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Rahelić D, Jenkins A, Bozikov V, Pavić E, Jurić K, Fairgrieve C, Romić D, Kokić S, Vuksan V. Glycemic index in diabetes. Coll Antropol 2011; 35:1363-1368. [PMID: 22397288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Glycemic Index (GI) is a rating system that ranks carbohydrate-containing foods according to their postprandial blood glucose response relative to the same quantity of available carbohydrate of a standard such as white bread or glucose. The concept of GI was first introduced in the early 80's by Jenkins and coworkers. Since then, numerous trials have been undertaken, many indicating benefits of a low GI diet on glycemic control, as well as lipid profiles, insulin and C-peptide levels, inflammatory and thrombolytic factors, endothelial function and regulation of body weight. As a result, a low-GI diet may prevent or delay the vascular complications of diabetes. However, despite many studies supporting the benefits of the Glycemic Index as part of the treatment of diabetes mellitus, several areas of controversy have been raised in the literature and are addressed here. Clinicians treating diabetic patients should be aware of the potential benefits of low-GI foods in the prevention and treatment of diabetes and its complications.
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Affiliation(s)
- Dario Rahelić
- University of Zagreb, Dubrava University Hospital, Division of Endocrinology, Diabetes and Metabolic Disease, Zagreb, Croatia.
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De Souza LR, Jenkins AL, Sievenpiper JL, Jovanovski E, Rahelić D, Vuksan V. Korean red ginseng (Panax ginseng C.A. Meyer) root fractions: differential effects on postprandial glycemia in healthy individuals. J Ethnopharmacol 2011; 137:245-250. [PMID: 21619921 DOI: 10.1016/j.jep.2011.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 04/15/2011] [Accepted: 05/10/2011] [Indexed: 05/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Variations in ginsenoside profile may predict the postprandial glucose (PPG)-lowering efficacy of ginseng. Previously we reported differential PPG-lowering effects with two Korean red ginseng (KRG) root. FRACTIONS: body and rootlets, of variable ginsenoside profiles. Whether this effect is reproducible with a different KRG source is unclear. We therefore tested two root fractions from a KRG source with elevated ginsenoside levels to assess its effect on PPG. MATERIALS AND METHODS After a 12-h overnight fast, 13 healthy individuals (6M:7F; age=28 ± 10 y; BMI=24.1 ± 3 kg/m2; FBG=4.77 ± 0.04 mmol/L) randomly received either 3g of KRG-body, rootlets or placebo, on three separate visits. Treatments were consumed 60 min prior to a standard test meal with capillary blood samples at -60, 0, 15, 30, 45, 60, 90 and 120 min. RESULTS The KRGrootlets had>6 fold total ginsensosides than the KRG-body but did not significantly affect PPG. Despite a reduced ginsenoside profile, KRG-body lowered PPG levels at 45, 60, 90 and 120 min during the test (p<0.05), rendering an overall reduction of 27% in incremental area under the glucose curve compared to the control (p<0.05). CONCLUSIONS Comparing the results with a previously studied batch of KRG suggests a potential therapeutic dose range for ginsenosides. This observation should be clinically verified with acute screening and ginsenoside composition analysis.
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Affiliation(s)
- Leanne R De Souza
- Clinical Nutrition and Risk Factor Modification Center and Li Ka Shing Knowledge Institute, St. Michael's Hospital, 70 Richmond St. E., Toronto, Ontario, Canada, M5C1N8
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Vuksan V, Sievenpipper J, Jovanovski E, Jenkins AL. Current Clinical Evidence for Korean Red Ginseng in Management of Diabetes and Vascular Disease: A Toronto's Ginseng Clinical Testing Program. J Ginseng Res 2010. [DOI: 10.5142/jgr.2010.34.4.264] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Vuksan V, Peeva V, Rogovik A, Beljan-Zdravkovic U, Stavro M, Jenkins A, Dias AG, Devanesen S, Sievenpiper J, Hanna A. The metabolic syndrome in healthy, multiethnic adolescents in Toronto, Ontario: the use of fasting blood glucose as a simple indicator. Can J Cardiol 2010; 26:e128-32. [PMID: 20352142 DOI: 10.1016/s0828-282x(10)70360-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The prevalence of the metabolic syndrome (MetS) is increasing worldwide and prevention represents a major challenge. Usually identified in middle age, the MetS has pediatric roots and there are variable incidence rates between ethnic groups. Due to the difficulty of diagnosis, it remains largely undetected in adolescents. OBJECTIVES To assess the presence of the MetS features in healthy, normal-weight, multiethnic adolescents and to determine whether fasting blood glucose (FBG) could function as a simple indicator of its presence. METHODS A convenience sample of secondary school students was used in a cross-sectional study. General linear model ANCOVA adjusted for multiple pairwise comparisons by the post hoc Tukey-Kramer test was used to assess differences among the tertiles of FBG. RESULTS A total of 182 adolescents from 62 Greater Toronto Area secondary schools in Ontario were recruited (44% Caucasian, 34% South Asian and 22% Chinese), with a mean (+/- SD) age of 17.4+/-0.9 years, a mean body mass index of 22.1+/-3.4 kg/m2 and a mean FBG of 4.92+/-0.4 mmol/L. Analysis with general linear model ANCOVA across the tertiles of FBG (3.83 mmol/L to 4.78 mmol/L, 4.79 mmol/L to 5.08 mmol/L, and 5.09 mmol/L to 6.45 mmol/L) showed significant linear increases of body mass index (P<0.005), waist circumference (P<0.001), systolic blood pressure (P<0.001) and diastolic blood pressure (P<0.05) with increasing FBG. Stepwise multiple regression analysis indicated systolic blood pressure (beta=0.0078, partial R2=0.039, P=0.007) and waist circumference (beta=0.0081, partial R2=0.025, P=0.035) were independent predictors of the increased FBG level. CONCLUSIONS MetS markers were present in a sample of healthy multiethnic adolescents in the Greater Toronto Area. FBG could be used as a simple indicator of the MetS to allow for early detection of the presence of the MetS and the introduction of preventive lifestyle measures. Further studies with larger sample sizes should address the accuracy of FBG for diagnosing the MetS.
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Affiliation(s)
- Vladimir Vuksan
- Clinical Nutrition and Risk Factor Modification Centre, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario.
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Jovanovski E, Jenkins A, Dias AG, Peeva V, Sievenpiper J, Arnason JT, Rahelic D, Josse RG, Vuksan V. Effects of Korean red ginseng (Panax ginseng C.A. Mayer) and its isolated ginsenosides and polysaccharides on arterial stiffness in healthy individuals. Am J Hypertens 2010; 23:469-72. [PMID: 20134405 DOI: 10.1038/ajh.2010.5] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Preclinical studies indicate a role of Korean red ginseng (KRG) in the modulation of vascular function; however, clinical evidence is scarce. Therefore, the objective of this study was to investigate the effect of KRG root on peripheral blood pressure (BP) and augmentation index (AI), an emerging method to assess cardiovascular risk beyond conventional BP measurements. Furthermore, in an attempt to elucidate which of the major components of KRG is responsible for these effects, the ginsenoside and polysaccharide fractions isolated from the same KRG root were also investigated. METHODS The study was designed as an acute randomized, controlled, double blind, crossover trial. A total of 17 healthy fasted individuals (gender: 9 males:8 females, age: 30 +/- 9 years, body mass index: 25 +/- 3 kg/m(2), systolic BP (SBP): 110 +/- 10.1, diastolic BP (DBP): 65 +/- 7 mm Hg) received, on separate occasions, four treatments consisting of: 3 g of either placebo, KRG root, or a KRG root bioequivalent dose of ginsenoside or polysaccharide fractions. BP and AI were measured by applanation tonometry at baseline, 1, 2, and 3 h post-treatment. RESULTS Compared to placebo, 3 g of KRG significantly lowered radial AI by 4.6% (P = 0.045), whereas the ginsenoside fraction comparably decreased AI by 4.8% (P = 0.057), and no effect was observed with the polysaccharides. There were no differences in BP between treatments. CONCLUSION Although preliminary, this study is the first to demonstrate that KRG may improve arterial stiffness as measured by AI. In addition, it appears that ginsenosides may be the principal pharmacologically active component of the root, rather than the polysaccharide fraction. This study supports the results seen with KRG in the preclinical studies and warrants further investigation on acute and long-term endothelial parameters.
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Vuksan V, Choleva L, Perrin‐Houdon S, Rogovik A, Fairgrieve C, Jenkins A. Improved Postprandial Glycemia and Appetite Scores after Addition of the Ancient Grain Salba (Salvia Hispanica L.) vs Flax to an OGTT: Possible Effect of Viscosity. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.231.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- Risk Factor Modification CenterSt. Michael's HospitalTorontoONCanada
- Nutritional SciencesUniversity of TorontoTorontoONCanada
| | - Lauryn Choleva
- Risk Factor Modification CenterSt. Michael's HospitalTorontoONCanada
- Nutritional SciencesUniversity of TorontoTorontoONCanada
| | | | - Alexander Rogovik
- Risk Factor Modification CenterSt. Michael's HospitalTorontoONCanada
| | | | - Alexandra Jenkins
- Risk Factor Modification CenterSt. Michael's HospitalTorontoONCanada
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Vuksan V, Rogovik A, Peeva V, Beljan‐Zdravkovic U, Stavro M, Jenkins A, Dias A, Devanesen S, Fairgrieve C, Hanna A. Metabolic syndrome in healthy, multiethnic adolescents in Toronto: the use of fasting blood glucose as a simple indicator. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.933.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- St. Michael's HospitalTorontoONCanada
- University of TorontoTorontoONCanada
| | | | | | | | | | | | - Andre Dias
- St. Michael's HospitalTorontoONCanada
- University of TorontoTorontoONCanada
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Jenkins A, Bateman E, Brissette C, Guendelman Y, Fairgrieve C, Vuksan V. Acute Response of Equicaloric Test Meals Varying in Glycemic Index and Glycemic Load on Postprandial Glycemia, Arterial Stiffness and Blood Pressure in Healthy Adults. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.324.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Emma Bateman
- Risk Factor Modification CentreSt Michael's HospitalTorontoONCanada
| | | | - Yael Guendelman
- Risk Factor Modification CentreSt Michael's HospitalTorontoONCanada
| | | | - Vladimir Vuksan
- Risk Factor Modification CentreSt Michael's HospitalTorontoONCanada
- Nutritional SciencesUniversity of TorontoTorontoONCanada
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Bhardwaj J, Bateman E, Sam C, Jovanovski E, Fairgrieve C, Jenkins A, Vuksan V. Efficacy of Rg3‐Enriched Korean Red Ginseng (Steamed Panax Ginseng C.A. Meyer) Extract on Arterial Stiffness and Blood Pressure in Healthy Volunteers. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.739.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jyoti Bhardwaj
- Department of Nutritional SciencesUniversity of TorontoTorontoONCanada
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Emma Bateman
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Clarissa Sam
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Elena Jovanovski
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | | | - Alexandra Jenkins
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Vladimir Vuksan
- Department of Nutritional SciencesUniversity of TorontoTorontoONCanada
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
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Petersen BL, Ward LS, Bastian ED, Jenkins AL, Campbell J, Vuksan V. A whey protein supplement decreases post-prandial glycemia. Nutr J 2009; 8:47. [PMID: 19835582 PMCID: PMC2766379 DOI: 10.1186/1475-2891-8-47] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 10/16/2009] [Indexed: 12/15/2022] Open
Abstract
Background Incidence of diabetes, obesity and insulin resistance are associated with high glycemic load diets. Identifying food components that decrease post-prandial glycemia may be beneficial for developing low glycemic foods and supplements. This study explores the glycemic impact of adding escalating doses of a glycemic index lowering peptide fraction (GILP) from whey to a glucose drink. Methods Ten healthy subjects (3M, 7F, 44.4 ± 9.3 years, BMI 33.6 ± 4.8 kg/m2) participated in an acute randomised controlled study. Zero, 5, 10 and 20 g of protein from GILP were added to a 50 g glucose drink. The control (0 g of GILP) meal was repeated 2 times. Capillary blood samples were taken fasting (0 min) and at 15, 30, 45, 60, 90 and 120 minutes after the start of the meal and analyzed for blood glucose concentration. Results Increasing doses of GILP decreased the incremental areas under the curve in a dose dependant manner (Pearson's r = 0.48, p = 0.002). The incremental areas (iAUC) under the glucose curve for the 0, 5, 10, and 20 g of protein from GILP were 231 ± 23, 212 ± 23, 196 ± 23, and 138 ± 13 mmol.min/L respectively. The iAUC of the 20 g GILP was significantly different from control, 5 g GILP and 10 g GILP (p < 0.001). Average reduction in the glucose iAUC was 4.6 ± 1.4 mmol.min/L per gram of ingested GILP. Conclusion Addition of GILP to a oral glucose bolus reduces blood glucose iAUC in a dose dependent manner and averages 4.6 ± 1.4 mmol.min/L per gram of GILP. These data are consistent with previous research on the effect of protein on the glycemic response of a meal.
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Abstract
In randomized controlled trials, viscous soluble fibers have demonstrated acute and long-term metabolic improvements in type 2 diabetes, such as reductions in hemoglobin A1c, fasting and post-prandial glycemia, insulinemia, and cardiovascular risk factors. In addition, they may be helpful in weight control through promoting feelings of fullness. Increasing consumption of foods containing fiber or use of fiber supplements could play an important role in managing diabetes with positive outcomes on vascular complications and reduced cardio-vascular disease risk.
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Affiliation(s)
- Vladimir Vuksan
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, 70 Richmond Street East, Suite 100, Toronto, ON, M5C 1N8, Canada.
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Vuksan V, Panahi S, Lyon M, Rogovik AL, Jenkins AL, Leiter LA. Viscosity of fiber preloads affects food intake in adolescents. Nutr Metab Cardiovasc Dis 2009; 19:498-503. [PMID: 19157816 DOI: 10.1016/j.numecd.2008.09.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 09/11/2008] [Accepted: 09/16/2008] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIMS Dietary fiber that develops viscosity in the gastrointestinal tract is capable of addressing various aspects of food intake control. The aim of this study was to assess subsequent food intake and appetite in relation to the level of viscosity following three liquid preloads each containing 5 g of either a high (novel viscous polysaccharide; NVP), medium (glucomannan; GLM), or low (cellulose; CE) viscosity fiber. METHODS AND RESULTS In this double-blind, randomized, controlled and crossover trial, 31 healthy weight adolescents (25 F:6 M; age 16.1+/-0.6 years; BMI 22.2+/-3.7 kg/m(2)) consumed one of the three preloads 90 min prior to an ad libitum pizza meal. Preloads were identical in taste, appearance, nutrient content and quantity of fiber, but different in their viscosities (10, 410, and 700 poise for CE, GLM, and NVP, respectively). Pizza intake was significantly lower (p=0.008) after consumption of the high-viscosity NVP (278+/-111 g) compared to the medium-viscosity GLM (313+/-123 g) and low-viscosity CE (316+/-138 g) preloads, with no difference between the GLM and CE preloads. Appetite scores, physical symptoms and 24-h intake did not differ among treatment groups. CONCLUSION A highly viscous NVP preload leads to reduced subsequent food intake, in terms of both gram weight and calories, in healthy weight adolescents. This study provides preliminary evidence of an independent contribution of viscosity on food intake and may form a basis for further studies on factors influencing food intake in adolescents.
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Affiliation(s)
- V Vuksan
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Wolever TMS, Vuksan V, Relle LK, Jenkins AL, Josse RG, Wong GS, Jenkins DJA. Glycaemic index of fruits and fruit products in patients with diabetes. Int J Food Sci Nutr 2009. [DOI: 10.3109/09637489309027544] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Jenkins A, Kacinik V, Lyon M, Wolever T, Vuksan V. Reduction of the glycemic index by a Novel Viscous Polysaccharide when added or incorporated into commonly consumed foods. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.351.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alexandra Jenkins
- Glycemic Index Laboratories, IncTorontoONCanada
- Risk Factor Modification CentreSt Michaels' HospitalTorontoONCanada
| | | | - Michael Lyon
- Canadian Center for Functional MedicineCoquitlamBCCanada
- Food, Nutrition and Health ProgramUniversity of British ColombiaVancouverBCCanada
| | | | - Vladimir Vuksan
- Glycemic Index Laboratories, IncTorontoONCanada
- Li Ka Shing Knowledge Centre, St Michael's HopsitalTorontoONCanada
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Vuksan V, Dias A, Lee A, Jovanovski E, Rogovik A, Jenkins A. Comparable Dose‐Response Glucose Lowering Effect with Whole vs finely Ground, Novel Omega‐3 rich Grain Salba (Salvia Hispanica L) Baked into White Bread. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.351.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- Department of Nutritional Sciences, Faculty of MedicineUniversity of TorontoTorontoONCanada
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Andre Dias
- Department of Nutritional Sciences, Faculty of MedicineUniversity of TorontoTorontoONCanada
| | - Amy Lee
- Department of Nutritional Sciences, Faculty of MedicineUniversity of TorontoTorontoONCanada
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Elena Jovanovski
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Alex Rogovik
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
| | - Alexandra Jenkins
- Risk Factor Modification CentreSt. Michael's HospitalTorontoONCanada
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Jenkins AL, Jenkins DJA, Wolever TMS, Rogovik AL, Jovanovski E, Bozikov V, Rahelić D, Vuksan V. Comparable postprandial glucose reductions with viscous fiber blend enriched biscuits in healthy subjects and patients with diabetes mellitus: acute randomized controlled clinical trial. Croat Med J 2009; 49:772-82. [PMID: 19090602 DOI: 10.3325/cmj.2008.49.722] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIM To compare the blood glucose-lowering effect of a highly viscous fiber blend (VFB) added to a starchy snack on postprandial glycemia between healthy participants and participants with diabetes mellitus. METHODS Ten healthy participants (4 men and 6 women, aged 28+/-2.6 years, body mass index [BMI], 24.3+/-0.8 kg/m(2)) and 9 participants with diabetes mellitus type 2 (3 men and 6 women, aged 68+/-3.8 years, BMI 28.8+/-1.2 kg/m(2)) on four separate occasions took either 50 g available carbohydrates as control biscuits, biscuits with 10 g of highly viscous fiber blend, white bread with 12 g of margarine, or white bread alone. Postprandial blood glucose response, glycemic index (GI), and palatability were determined. RESULTS Mean (95% confidence interval) GI values of the viscous fiber blend biscuits were 26 (16-36) and 37 (27-47) GI units for healthy participants and participants with diabetes mellitus, respectively. These values were significantly lower than those of white bread, white bread with 12 g of margarine, and control biscuits (P<0.001, paired t test) both in healthy participants (GI 100, 108 [57-159], and 101 [44-158], respectively) and participants with diabetes mellitus (GI 100, 103 [79-127], and 94 [78-110], respectively). Viscous fiber blend significantly reduced the glycemic index by 74% (7.4 GI units/g of fiber) in healthy participants and by 63% (6.3 GI units/g of fiber) in participants with diabetes. The GI did not differ between control meals in both healthy participants and participants with diabetes. There were no significant differences in palatability among the types of meals, although participants with diabetes found the viscous fiber blend biscuits more palatable (P=0.002, t test). CONCLUSION Viscous fiber blend is a very potent and palatable soluble fiber addition to a starchy snack, which is able to reduce the glycemic response to a similar extent in both healthy participants and individuals with diabetes mellitus. Biscuits with low GI, and possibly other viscous fiber blend fortified starchy foods, may potentially be a useful replacement of high GI snack foods in the diet.
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Affiliation(s)
- Alexandra L Jenkins
- Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital and Li Ka Shing Knowledge Institute, 70 Richmond St. E., Toronto, Ontario, Canada
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Vuksan V, Jenkins AL, Jenkins DJA, Rogovik AL, Sievenpiper JL, Jovanovski E. Using cereal to increase dietary fiber intake to the recommended level and the effect of fiber on bowel function in healthy persons consuming North American diets. Am J Clin Nutr 2008; 88:1256-62. [PMID: 18996860 DOI: 10.3945/ajcn.2008.25956] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Dietary fiber intake remains low despite increasing evidence for its health benefits, including laxation. OBJECTIVE We aimed to assess the effects of increasing fiber intake on bowel habits and gastrointestinal tolerance in healthy persons consuming a typical Canadian or US diet. DESIGN Under a randomized crossover design, 23 free-living participants consumed a typical Canadian or US diet (35% fat, 12 g fiber/d) and received 25.0-28.7 g fiber/d from each of 5 breakfast cereals: All-Bran (AB), Bran Buds with Corn (BBC), Bran Buds with Psyllium (BBP), BBC with viscous fiber blend (VFB), or a low-fiber control for 3 wk, with each study arm separated by a washout of >/=1 wk. Seven-day stool collections and a symptom diary were obtained during the last week of each study arm. RESULTS All study cereals induced significant (P < 0.05) increases in fecal bulk from the control diet at 128 +/- 38 g to 199 +/- 56, 199 +/- 57, 247 +/- 87, and 197 +/- 63 g with consumption of AB, BBC, BBP, and VFB, respectively; less intestinal transit time; and significantly (P < 0.05) greater bowel movement frequency. Despite the increased activity of the bowel, a positive level of comfort was maintained. BBP was more effective than other cereals in terms of increasing fecal wet weight (P < 0.05). CONCLUSION Water-insoluble dietary fibers (ie, AB and BBC) and their mixtures with water-soluble fibers (ie, BBP and VFB) in the form of breakfast cereals (2.5 servings/d) proved to be a practical way of increasing fiber intake to recommended levels, while maintaining a good level of tolerance.
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Affiliation(s)
- Vladimir Vuksan
- Clinical Nutrition & Risk Factor Modification Center, St Michael's Hospital, Toronto, Canada.
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Retnakaran R, Shen S, Hanley AJ, Vuksan V, Hamilton JK, Zinman B. Hyperbolic relationship between insulin secretion and sensitivity on oral glucose tolerance test. Obesity (Silver Spring) 2008; 16:1901-7. [PMID: 18551118 DOI: 10.1038/oby.2008.307] [Citation(s) in RCA: 262] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The utility of the disposition index as a measure of beta-cell compensatory capacity rests on the established hyperbolic relationship between its component insulin secretion and sensitivity measures as derived from the intravenous glucose tolerance test (IVGTT). If one is to derive an analogous measure of beta-cell compensation from the oral glucose tolerance test (OGTT), it is thus necessary to first establish the existence of this hyperbolic relationship between OGTT-based measures of insulin secretion and insulin sensitivity. In this context, we tested five OGTT-based measures of secretion (insulinogenic index, Stumvoll first phase, Stumvoll second phase, ratio of total area-under-the-insulin-curve to area-under-the-glucose-curve (AUC(ins/gluc)), and incremental AUC(ins/gluc)) with two measures of sensitivity (Matsuda index and 1/Homeostasis Model of Assessment for insulin resistance (HOMA-IR)). Using a model of log(secretion measure) = constant + beta x log(sensitivity measure), a hyperbolic relationship can be established if beta is approximately equal to -1, with 95% confidence interval (CI) excluding 0. In 277 women with normal glucose tolerance (NGT), the pairing of total AUC(ins/gluc) and Matsuda index was the only combination that satisfied these criteria (beta = -0.99, 95% CI (-1.66, -0.33)). This pairing also satisfied hyperbolic criteria in 53 women with impaired glucose tolerance (IGT) (beta = -1.02, (-1.72, -0.32)). In a separate data set, this pairing yielded distinct hyperbolae for NGT (n = 245) (beta = -0.99, (-1.67, -0.32)), IGT (n = 116) (beta = -1.18, (-1.84, -0.53)), and diabetes (n = 43) (beta = -1.37, (-2.46, -0.29)). Moreover, the product of AUC(ins/gluc) and Matsuda index progressively decreased from NGT (212) to IGT (193) to diabetes (104) (P < 0.001), consistent with declining beta-cell function. In summary, a hyperbolic relationship can be demonstrated between OGTT-derived AUC(ins/gluc) and Matsuda index across a range of glucose tolerance. Based on these findings, the product of these two indices emerges as a potential OGTT-based measure of beta-cell function.
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Affiliation(s)
- Ravi Retnakaran
- Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, Ontario, Canada.
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Panahi S, Ezatagha A, Temelli F, Vasanthan T, Vuksan V. Beta-glucan from two sources of oat concentrates affect postprandial glycemia in relation to the level of viscosity. J Am Coll Nutr 2008; 26:639-44. [PMID: 18187427 DOI: 10.1080/07315724.2007.10719641] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Soluble dietary fiber has been shown to attenuate the postprandial rise in blood glucose levels and reduce the risk of type 2 diabetes and cardiovascular disease. This effect seems to be related to its rheological properties including viscosity. We examined the intra-fiber variability between two different processing methods of concentrating beta-glucan from oats (aqueous vs. enzymatic) in relation to the level of viscosity of beta-glucan and its effect on postprandial glycemia in healthy individuals. DESIGN In an acute, randomized, double-blind, crossover study, 11 healthy subjects (gender: 5M:6F; age: 34 +/- 5 years; BMI: 23 +/- 0.8 kg/m(2)) were randomly assigned, on three separate occasions, to consume one of three fiber-matched treatments along with a 75 g oral glucose drink. The enzymatically processed beta-glucan (Oat-A) differed from beta-glucan processed through the aqueous method (Oat-B) solely with regard to viscosity. Finger-prick capillary blood samples were obtained at fasting and at 15, 30, 45, 60, 90 and 120 min after the start of the test drink. The viscosities of the fiber drinks were determined (Paar Physica UDS200 viscometer). RESULTS Rheological measurements demonstrated that Oat-A had a significantly higher viscosity than Oat-B and control at 5, 15, 30, 60, and 120 min (p < 0.001). The incremental area under the glucose curve (AUC) on Oat-A was 19.6% and 17% lower than that of Oat-B and control, respectively (p < 0.01). CONCLUSIONS This study shows that processing oat beta-glucan through enzymatic, rather than by aqueous methods, preserves the viscosity and improves postprandial glycemic control.
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Affiliation(s)
- Shirin Panahi
- University of Toronto, Faculty of Medicine, Department of Nutritional Sciences, Toronto, ON, M5S 3E2, Canada
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Vuksan V, Dias A, Chiavaroli L, Lee A. The Effects of Escalating Quantities of Salvia hispanica L. (Salba) on Postprandial Glycemia and Appetite in Healthy Individuals. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.305.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- Nutritional SciencesUniversity of TorontoTorontoCanada
- Risk Factor Modification CenterSt Michael's HospitalTorontoCanada
| | - Andre Dias
- Nutritional SciencesUniversity of TorontoTorontoCanada
- Risk Factor Modification CenterSt Michael's HospitalTorontoCanada
| | - Laura Chiavaroli
- Nutritional SciencesUniversity of TorontoTorontoCanada
- Risk Factor Modification CenterSt Michael's HospitalTorontoCanada
| | - Amy Lee
- Nutritional SciencesUniversity of TorontoTorontoCanada
- Risk Factor Modification CenterSt Michael's HospitalTorontoCanada
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71
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Jenkins A, Vuksan V, Kacinik V, Lyon M. Glycemic Index Reduction by a Viscous Polysaccharide Blend Independent of Food Form: Determination of the Glycemic Reduction Index Potential (GRIP). FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.305.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Vladimir Vuksan
- Nutritional SciencesUniversity of TorontoTorontoCanada
- Risk Factor Modification CenterSt Michael's HospitalTorontoCanada
| | | | - Michael Lyon
- Canadian Centre for Functional MedicineCoquitlamCanada
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Vuksan V, Sung MK, Sievenpiper JL, Stavro PM, Jenkins AL, Di Buono M, Lee KS, Leiter LA, Nam KY, Arnason JT, Choi M, Naeem A. Korean red ginseng (Panax ginseng) improves glucose and insulin regulation in well-controlled, type 2 diabetes: results of a randomized, double-blind, placebo-controlled study of efficacy and safety. Nutr Metab Cardiovasc Dis 2008; 18:46-56. [PMID: 16860976 DOI: 10.1016/j.numecd.2006.04.003] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 04/18/2006] [Accepted: 04/19/2006] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND AIM To address the paucity of randomized clinical studies assessing ginseng on long-term outcomes in type 2 diabetes, we assessed the clinical antidiabetic efficacy and safety of 12 weeks of supplementation with a Korean red ginseng (KRG) preparation, dose, and mode of administration, selected from an acute, clinical, screening model. METHODS AND RESULTS Nineteen participants with well-controlled type 2 diabetes (sex: 11 M:8 F, age: 64+/-2 years, BMI: 28.9+/-1.4 kg/m(2), HbA(1c): 6.5%) completed the study. Using a double-blind, randomized, crossover design, each participant received the selected KRG preparation (rootlets) and placebo at the selected dose (2 g/meal=6 g/day) and mode of administration (preprandial oral agent [-40 min]) for 12 weeks as an adjunct to their usual anti-diabetic therapy (diet and/or medications). Outcomes included measures of efficacy (HbA1c and fasting- and 75-g oral glucose tolerance test [OGTT]-plasma glucose [PG], plasma insulin [PI], and insulin sensitivity index [ISI] indices); safety (liver, kidney, haemostatic, and blood-pressure function); and compliance (returned capsules, diet-records, and body-weight). There was no change in the primary endpoint, HbA(1c). The participants, however, remained well-controlled (HbA1c=6.5%) throughout. The selected KRG treatment also decreased 75 g-OGTT-PG indices by 8-11% and fasting-PI and 75 g-OGTT-PI indices by 33-38% and increased fasting-ISI (homeostasis model assessment [HOMA]) and 75 g-OGTT-ISI by 33%, compared with placebo (P<0.05). Safety and compliance outcomes remained unchanged. CONCLUSIONS Although clinical efficacy, as assessed by HbA1c, was not demonstrated, 12 weeks of supplementation with the selected KRG treatment maintained good glycemic control and improved PG and PI regulation safely beyond usual therapy in people with well-controlled type 2 diabetes. Further investigation with similarly selected KRG treatments may yield clinical efficacy.
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Affiliation(s)
- Vladimir Vuksan
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada.
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Vuksan V, Whitham D, Sievenpiper JL, Jenkins AL, Rogovik AL, Bazinet RP, Vidgen E, Hanna A. Supplementation of conventional therapy with the novel grain Salba (Salvia hispanica L.) improves major and emerging cardiovascular risk factors in type 2 diabetes: results of a randomized controlled trial. Diabetes Care 2007; 30:2804-10. [PMID: 17686832 DOI: 10.2337/dc07-1144] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine whether addition of Salba (Salvia hispanica L.), a novel whole grain that is rich in fiber, alpha-linolenic acid (ALA), and minerals to conventional treatment is associated with improvement in major and emerging cardiovascular risk factors in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS Using a single-blind cross-over design, subjects were randomly assigned to receive either 37 +/- 4 g/day of Salba or wheat bran for 12 weeks while maintaining their conventional diabetes therapies. Twenty well-controlled subjects with type 2 diabetes (11 men and 9 women, aged 64 +/- 8 years, BMI 28 +/- 4 kg/m2, and A1C 6.8 +/- 0.9%) completed the study. This study was set in the outpatient clinic of the Risk Factor Modification Center, St. Michael's Hospital, Toronto, Canada. RESULTS Compared with the control treatment, Salba reduced systolic blood pressure (SBP) by 6.3 +/- 4 mmHg (P < 0.001), high-sensitivity C-reactive protein (hs-CRP) (mg/l) by 40 +/- 1.6% (P = 0.04), and vonWillebrand factor (vWF) by 21 +/- 0.3% (P = 0.03), with significant decreases in A1C and fibrinogen in relation to the Salba baseline but not with the control treatment. There were no changes in safety parameters including liver, kidney and hemostatic function, or body weight. Both plasma ALA and eicosapentaenoic polyunsaturated fatty acid levels were increased twofold (P < 0.05) while consuming Salba. CONCLUSIONS Long-term supplementation with Salba attenuated a major cardiovascular risk factor (SBP) and emerging factors (hs-CRP and vWF) safely beyond conventional therapy, while maintaining good glycemic and lipid control in people with well-controlled type 2 diabetes.
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Affiliation(s)
- Vladimir Vuksan
- Risk Factor Modification Centre, St. Michael's Hospital, 70 Richmond St. East, Toronto, Ontario, Canada, M5C 1N8.
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Dascalu A, Sievenpiper JL, Jenkins AL, Stavro MP, Leiter LA, Arnason JT, Vuksan V. Five batches representative of Ontario-grown American ginseng root produce comparable reductions of postprandial glycemia in healthy individualsThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products. Can J Physiol Pharmacol 2007; 85:856-64. [DOI: 10.1139/y07-030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Evidence indicates that the glycemia-lowering effect of American ginseng root may be batch dependent. We therefore evaluated the effect of 5 root batches, representative of Ontario-grown American ginseng, on postprandial glucose and insulin indices. Twelve healthy subjects (5 male, 7 female), mean ± SE age 26.5 ± 2 years, body mass index 23.96 ± 3.41 kg/m2, fasting blood glucose 4.77 ± 0.04 mmol/L, were assigned to consume 9 g of American ginseng from 5 farms (A–E), administered in randomized sequence on 5 separate visits, and a water-control during the 6th and last visit. Treatments were consumed 40 min before a 2-hour 75-gram oral glucose tolerance test. Plasma glucose and insulin were measured at baseline, before, and during the test. Compared with control, batches A and C reduced glucose incremental area under the curve (IAUC) by 35.2% (156 vs. 240 mmol·min/L) and 32.6% (162 vs. 240 mmol·min/L), respectively. Batches A, C, and E reduced incremental peak glucose by 1.3, 1.2, and 1.1 mmol/L, respectively. Batch C reduced the insulin IAUC by 27.7% (15.8 vs. 21.8 nmol·min/L). Effects on glucose and insulin parameters were not different across ginseng treatments. The mean of the 5 ginseng treatments reduced peak postprandial glucose by 1.0 mmol/L, glucose IAUC by 27.7% (173 vs. 240 mmol·min/L), and insulin IAUC by 23.8% (16.6 vs. 21.8 nmol·min/L) relative to control. (All results statistically significant at p < 0.05.) American ginseng decreased postprandial glycemia and insulinemia; however, 40% of the batches did not reduce glycemia with the anticipated magnitude, irrespective of their saponin composition.
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Affiliation(s)
- Anamaria Dascalu
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - John L. Sievenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Alexandra L. Jenkins
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Mark P. Stavro
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Lawrence A. Leiter
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - John Thor Arnason
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Vladimir Vuksan
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E2, Canada
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK
- Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, 70 Richmond Street East, Toronto, ON M5C 1N8, Canada
- Division of Endocrinology and Metabolism, St. Michael’s Hospital, Toronto, ON M5C 2T2, Canada
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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Abstract
AIMS Placebo effects in clinical trials remain uncertain. To investigate a placebo effect on acute postprandial plasma glucose, we conducted a follow-up investigation on a previous study. METHODS The effect of placebo (9 g encapsulated cornstarch +500 ml water, taken at -40 min) on the plasma glucose response to a 75-g oral glucose tolerance test (OGTT) was assessed in a previous study in 12 healthy subjects (gender, five male, seven female; age 27 +/- 6 years; body mass index 24 +/- 3.4 kg m(-2)). This was compared with the effect of a water control (500 ml water taken alone at -40 min) on the same outcome in the same subjects in a follow-up study. RESULTS Cornstarch placebo decreased plasma glucose area under the curve during the 75-g OGTT by 28% [Delta (95% confidence interval) -63.3 min mmol(-1) l(-1) (-218.33, 91.66), P < 0.02] compared with the water control (P < 0.05). CONCLUSIONS Postprandial plasma glucose outcomes may be vulnerable to placebo effects.
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Affiliation(s)
- John L Sievenpiper
- Risk Factor Modification Centre, St Michael's Hospital and Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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76
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Abstract
BACKGROUND Body mass index (BMI) is widely used to assess risk for cardiovascular disease and type 2 diabetes. Cut points for the classification of obesity (BMI >30 kg/m2) have been developed and validated among people of European descent. It is unknown whether these cut points are appropriate for non-European populations. We assessed the metabolic risk associated with BMI among South Asians, Chinese, Aboriginals, and Europeans. METHODS AND RESULTS We randomly sampled 1078 subjects from 4 ethnic groups (289 South Asians, 281 Chinese, 207 Aboriginals, and 301 Europeans) from 4 regions in Canada. Principal components factor analysis was used to derive underlying latent or "hidden" factors associated with 14 clinical and biochemical cardiometabolic markers. Ethnic-specific BMI cut points were derived for 3 cardiometabolic factors. Three primary latent factors emerged that accounted for 56% of the variation in markers of glucose metabolism, lipid metabolism, and blood pressure. For a given BMI, elevated levels of glucose- and lipid-related factors were more likely to be present in South Asians, Chinese, and Aboriginals compared with Europeans, and elevated levels of the blood pressure-related factor were more likely to be present among Chinese compared with Europeans. The cut point to define obesity, as defined by distribution of glucose and lipid factors, is lower by approximately 6 kg/m2 among non-European groups compared with Europeans. CONCLUSIONS Revisions may be warranted for BMI cut points to define obesity among South Asians, Chinese, and Aboriginals. Using these revised cut points would greatly increase the estimated burden of obesity-related metabolic disorders among non-European populations.
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Affiliation(s)
- Fahad Razak
- Population Health Research Institute, McMaster University, Hamilton, ON, Canada
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Sievenpiper JL, Sung MK, Di Buono M, Seung-Lee K, Nam KY, Arnason JT, Leiter LA, Vuksan V. Korean red ginseng rootlets decrease acute postprandial glycemia: results from sequential preparation- and dose-finding studies. J Am Coll Nutr 2006; 25:100-7. [PMID: 16582025 DOI: 10.1080/07315724.2006.10719519] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Fractionation of a ginseng source to produce differences in the ginsenoside profile might influence its effect on postprandial glycemia. To explore this possibility and identify an efficacious ginseng for a longterm study, we conducted a preparation-finding study of different Korean red ginseng (KRG) root fractions followed by a dose-finding study of the most efficacious fraction. METHODS A double-blind, randomized, within-subject design was used in both studies. In the preparation-finding study, 7 healthy subjects (sex: 3m:4f, age: 32 +/- 4 y, BMI: 24 +/- 2 kg/m2) received 6 g placebo and KRG-rootlets, -body, and -H2O extract 40 min before a 50 g-OGTT with finger-prick blood samples at -40-, 0-, 15-, 30-, 45-, 60-, 90-, 120-min. In the dose-finding study, 12 healthy subjects (sex: 9M,3F, age: 29 +/- 3 y, BMI: 22.5 +/- 1 kg/m2) received 0 g (placebo), 2 g, 4 g, and 6 g of the most efficacious root fraction following the same protocol. Ginsenosides were analyzed using HPLC-UV. RESULTS In the preparation-finding study, a wide variation in the ginsenoside profiles was achieved across the 3 KRG fractions. This variation coincided with differential effects. The main effects of KRG-rootlets (p = 0.050) and time (p < 0.001) and their interaction (p < 0.1) were significant. This was reflected in a 29% reduction in area under the curve (AUC) by KRG-rootlets compared with placebo (p = 0.052). Conversely, neither KRG-H2O extract nor KRG-body affected glycemia. Stepwise-multiple regression models identified Rg1 as the sole predictor of mean- and AUC postprandial blood glucose. In the dose-finding study, KRG-rootlets were tested as the most efficacious fraction. A significant effect of KRG-rootlets treatment (mean of 3 doses) but not dose was found. The mean of 3 doses decreased AUC by 17% compared with placebo (p = 0.057). CONCLUSIONS Together the studies indicate 2 g KRG-rootlets is sufficient to achieve reproducible reductions in postprandial glycemia. But the longterm sustainability of KRG selected using this approach remains to be tested.
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Affiliation(s)
- John L Sievenpiper
- Department of nutritional sciences, Faculty of Medicine, University of Toronto, Canada
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78
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Jovanovski E, Dascalu A, Jenkins A, Sievenpiper JL, Vuksan V. American Ginseng From Five Different Sources Has Differential Effects On Postprandial Blood Glucose. FASEB J 2006. [DOI: 10.1096/fasebj.20.5.a1019-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Jovanovski
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Anamaria Dascalu
- Risk Factor Modification CentreSt. Michael's Hospital61 Queen st EastTorontoOntarioM5C 2T2Canada
| | - Alexandra Jenkins
- Risk Factor Modification CentreSt. Michael's Hospital61 Queen st EastTorontoOntarioM5C 2T2Canada
| | - John L. Sievenpiper
- Risk Factor Modification CentreSt. Michael's Hospital61 Queen st EastTorontoOntarioM5C 2T2Canada
| | - Vladimir Vuksan
- Risk Factor Modification CentreSt. Michael's Hospital61 Queen st EastTorontoOntarioM5C 2T2Canada
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Ezatagha A, Dascalu A, Sievenpiper JL, Jovanovski E, Panahi S, Jenkins A, Vuksan V. Do all placebos fit the definition of a “placebo”? The variation in glycemic response of different placebos in healthy individuals. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adish Ezatagha
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - Anamaria Dascalu
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - John L. Sievenpiper
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - Elena Jovanovski
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - Shirin Panahi
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - Alexandra Jenkins
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
| | - Vladimir Vuksan
- Department of Nutritional SciencesUniversity of Toronto6129–61 Queen St ETorontoOntarioM5C 2T2Canada
- Risk Factor Modification CentreSt. Michael’s Hospital6129–61 Queen St. ETorontoOntarioM5C 2T2Canada
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Stavro PM, Woo M, Leiter LA, Heim TF, Sievenpiper JL, Vuksan V. Long-term intake of North American ginseng has no effect on 24-hour blood pressure and renal function. Hypertension 2006; 47:791-6. [PMID: 16520410 DOI: 10.1161/01.hyp.0000205150.43169.2c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ginseng is consumed by 10% to 20% of adults in Asia and by up to 5% in Western countries. Despite observational evidence suggesting a link between its intake and the development of hypertension, there remains no long-term scrutiny for its effect on blood pressure (BP). We therefore undertook a randomized, placebo-controlled, double-blinded, crossover trial in 52 hypertensive individuals to determine the effect of 12-week North American ginseng intake on 24-hour BP; we also measured serum cystatin C as a marker of renal function. After a 4-week placebo run-in, we randomly assigned 52 participants to 3 g/day of ginseng or placebo for 12 weeks. This was followed by an 8-week washout and a subsequent 12-week period in which the opposite treatment was administered. At run-in and at weeks 0 and 12 of each treatment period, participants were fitted with an ambulatory BP monitor to assess 24-hour BP. The primary outcome was the treatment difference at week 12 in mean 24-hour systolic BP. Secondary outcomes were treatment differences at week 12 in other ambulatory BP parameters and serum cystatin C. Forty participants (77%) completed the trial, with 3 removed from main analysis (n=2, antihypertensive drug changes; n=1, incomplete ambulatory monitoring). In the remaining 37, 12-week ginseng treatment was associated with a neutral effect on all ambulatory BP parameters compared with placebo; an intention-to-treat analysis supported this. Ginseng did not affect serum cystatin C level. Overall, long-term ginseng use had no effect on 24-hour BP and renal function in hypertensive individuals.
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Affiliation(s)
- P Mark Stavro
- Risk Factor Modification Centre, St Michael's Hospital, Toronto, Ontario, Canada
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81
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Vuksan V, Rogovik A, Ezatagha A, Panahi S, Jenkins A, Breitman P, Sievenpiper J. Viscosity rather than quantity determines lipid lowering effects of dietary fiber in individuals consuming typical North American diet. FASEB J 2006. [DOI: 10.1096/fasebj.20.5.a1027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- St. Michael's Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
| | - Alex Rogovik
- St. Michael's Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
| | - Adish Ezatagha
- St. Michael's Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
| | - Shirin Panahi
- St. Michael's Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
| | | | - Pearl Breitman
- St. Michael's Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
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82
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Vuksan V, Whitham D, Rogovik A, Sievenpiper J, DiBuono M, Jenkins A, Bazinet R. Effect of Novel Grains as a source of ù‐3 Fatty Acids and Functional food Components on Major and Emerging Risk Factors for Cardiovascular Disease in Type 2 Diabetes. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a430-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir Vuksan
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
- Nutritional SciencesUniversity of Toronto150 College StTorontoONM5C 3E2Canada
| | - Dana Whitham
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
| | - Alex Rogovik
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
| | - John Sievenpiper
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
- Nutritional SciencesUniversity of Toronto150 College StTorontoONM5C 3E2Canada
| | - Marco DiBuono
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
| | - Alexandra Jenkins
- Risk Factor Modification CentreSt Michael’s Hospital61 Queen St ETorontoONM5C 2T2Canada
| | - Richard Bazinet
- Nutritional SciencesUniversity of Toronto150 College StTorontoONM5C 3E2Canada
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83
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Jovanovski E, Ezatagha A, Panahi S, Dascalu A, Stavro M, Vuksan V. Root Fractions of Korean Red Ginseng (Panax Ginseng) Have Differential Effect on Blood Pressure and Blood Glucose Control In Healthy Individuals. FASEB J 2006. [DOI: 10.1096/fasebj.20.5.a1108-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Jovanovski
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Adish Ezatagha
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Shirin Panahi
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Anamaria Dascalu
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Mark Stavro
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
| | - Vladimir Vuksan
- Risk Factor Modification CentreSt. Michael's Hospial61 Queen St EastTorontoOntarioM5C 2T2Canada
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84
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Rogovik A, Jenkins A, Breitman P, Vuksan V. A blend of highly viscous polysaccharide decreases relative CVD risk in healthy individuals and those with diabetes and metabolic syndrome. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a578-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alex Rogovik
- St. Michael’s Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
| | | | - Pearl Breitman
- St. Michael’s Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
| | - Vladimir Vuksan
- St. Michael’s Hospital61 Queen St. E.TorontoOntarioM5C2T2Canada
- Nutrition SciencesUniversity of Toronto150 College St.TorontoOntarioM5C3E2Canada
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85
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Panahi S, Ezatagha A, Jovanovski E, Dascalu A, Jenkins A, Temelli F, Vasanthan T, Rogovik A, Vuksan V. β‐glucan from oat and barley concentrates affect postprandial glycemia and insulinemia in relation to the level of viscosity. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shirin Panahi
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Adish Ezatagha
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Elena Jovanovski
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Anamaria Dascalu
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Alexandra Jenkins
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Feral Temelli
- Department of AgricultureFood and Nutritional ScienceUniversity of Alberta4–10 Agriculture‐Forestry CentreEdmontonAlbertaT6G 2P5Canada
| | - Thava Vasanthan
- Department of AgricultureFood and Nutritional ScienceUniversity of Alberta4–10 Agriculture‐Forestry CentreEdmontonAlbertaT6G 2P5Canada
| | - Alex Rogovik
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
| | - Vladimir Vuksan
- Nutritional SciencesFaculty of MedicineUniversity of Toronto150 College StreetTorontoOntarioM5S3E2Canada
- St. Michael’s Hospital61 Queen Street EastTorontoOntarioM5C 2T2Canada
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86
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Breitman PL, Ezatagha A, Panahi S, Vuksan V. INDUCED FIBER VISCOSITY TRIPLES ITS EFFECT ON POSTPRANDIAL BLOOD GLUCOSE RESPONSE. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a599-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Pearl L. Breitman
- Nutritional SciencesUniversity of Toronto61 Queen Street East, 6th FloorTorontoOntarioM5C2T2Canada
| | - Adish Ezatagha
- Nutritional SciencesUniversity of Toronto61 Queen Street East, 6th FloorTorontoOntarioM5C2T2Canada
| | - Shirin Panahi
- Nutritional SciencesUniversity of Toronto61 Queen Street East, 6th FloorTorontoOntarioM5C2T2Canada
| | - Vladimir Vuksan
- Nutritional SciencesUniversity of Toronto61 Queen Street East, 6th FloorTorontoOntarioM5C2T2Canada
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Abstract
An early observational study suggested that ginseng could elevate blood pressure. This caused concern because 4.5% of American adults use ginseng, with a popular choice being North American ginseng. To date, North American ginseng lacks hemodynamic evaluation; therefore, we conducted a randomized, double-blinded, controlled trial to investigate its effect on blood pressure in 16 hypertensive individuals (mean+/-SD age 61.1+/-8.1 years; systolic/diastolic blood pressure 132.4+/-12.8/83.3+/-8.1 mm Hg; 13 on antihypertensives). We used 6 batches of North American ginseng root that varied in quality and ginsenoside content, representing the spectrum of this ginseng on the market. On 8 mornings, each participant was fitted with an ambulatory blood pressure monitor, which measured blood pressure during a 30-minute baseline period. Each participant then consumed in a randomized and double-blind fashion 3 g of encapsulated treatment: placebo (on 2 mornings) or powdered North American ginseng (on 6 mornings). After treatment, blood pressure was measured every 10 minutes for 160 minutes, and its change at each post-treatment time point relative to baseline was determined per individual and averaged, and the mean was obtained for the overall 160-minute period. None of the North American ginsengs or their mean differed from placebo in their effect on overall (160 minutes) mean blood pressure change. None affected blood pressure versus placebo at the 10-minute intervals; but their mean versus placebo increased systolic and diastolic blood pressure at 140 and 160 minutes, respectively, and lowered diastolic blood pressure at 100 minutes. The findings together suggested that North American ginseng exerts a neutral acute effect on blood pressure in hypertensive individuals.
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Affiliation(s)
- P Mark Stavro
- Risk Factor Modification Centre, St. Michael's Hospital, 61 Queen St E, 6th Floor, Suite 138, Toronto, Ontario, M5C 2T2, Canada
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88
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Vuksan V, Sievenpiper JL. Herbal remedies in the management of diabetes: lessons learned from the study of ginseng. Nutr Metab Cardiovasc Dis 2005; 15:149-160. [PMID: 15955462 DOI: 10.1016/j.numecd.2005.05.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 04/27/2005] [Accepted: 05/05/2005] [Indexed: 11/16/2022]
Abstract
The only example of an approved antidiabetic drug that was developed from a herbal source with a long history of use for diabetes is the biguanide Metformin from French lilac (Galega officinalis). Clinical data are beginning to emerge that support antidiabetic indications for several other herbs. This viewpoint discusses the state of the evidence for their clinical antidiabetic efficacy. One of the most studied herbs, ginseng (Panax spp.), is used as a model to illustrate the challenges associated with achieving reproducible clinical efficacy. It is concluded that the best evidence for clinical efficacy in diabetes remains for ginseng. But overall insufficient evidence exists to claim a diabetes indication for herbs. The experience with ginseng suggests that although reproducible efficacy may be achieved using an acute postprandial clinical screening model to select an efficacious ginseng batch, dose, and time of administration, there is a need to develop a basis for standardization that ties the composition of herbs to efficacy. In absence of such standardization, the use of herbs in diabetes must be approached cautiously.
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Affiliation(s)
- Vladimir Vuksan
- Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Canada.
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89
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Razak F, Anand S, Vuksan V, Davis B, Jacobs R, Teo KK, Yusuf S. Ethnic differences in the relationships between obesity and glucose-metabolic abnormalities: a cross-sectional population-based study. Int J Obes (Lond) 2005; 29:656-67. [PMID: 15782225 DOI: 10.1038/sj.ijo.0802937] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES To evaluate whether body mass index (BMI) and other anthropometric indices of visceral obesity vary by ethnic group in their distribution and their relationship to metabolic abnormalities. DESIGN Cross-sectional study. PARTICIPANTS Canadian men and women, aged 35-75 years, of South Asian (n=342), Chinese (n=317), European (n=326) and Aboriginal (n=301) descent were recruited using stratified random sampling. PRIMARY MEASURES Anthropometric indices (BMI, waist to hip ratio (WHR) and waist circumference (WC)), metabolic markers (fasting glucose, HbA1c, the ratio of total cholesterol/HDL) and clinical markers (systolic blood pressure) were assessed. RESULTS In subjects with BMI<30 kg/m2, the mean marker levels in people with elevated WC (>88 cm in women, >102 cm in men) vs people with normal WC were 6.16 vs 5.34 mmol/l for fasting glucose, 6.05 vs 5.66% for HbA1c and 5.46 vs 4.68 for the ratio of total cholesterol to HDL (P<0.001 in each case). At nearly every given level of BMI, non-European ethnic groups displayed significantly higher marker levels than Europeans. For example, for a given BMI, age and sex, the difference between European and non-European groups in HbA1c levels was 0.53% (95% confidence interval (CI): 0.37-0.69) for South Asians, 0.37% (95% CI: 0.2-0.54) for Chinese and 0.95% (95% CI: 0.78-1.12) for Aboriginal People. CONCLUSIONS Uniform cut-points for the classification of obesity using BMI, WHR or WC result in marked variation in the levels of glucose-metabolic abnormalities between ethnic groups. Existing action thresholds for these anthropometric indices do not apply to non-European ethnic groups and warrant revision.
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Affiliation(s)
- F Razak
- Population Health Research Institute, McMaster University, Hamilton General Hospital, Hamilton, ON, Canada
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90
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Kelemen LE, Anand SS, Hegele RA, Stampfer MJ, Rosner B, Willett WC, Montague PA, Lonn E, Vuksan V, Teo KK, Devanesen S, Yusuf S. Associations of plasma homocysteine and the methylenetetrahydrofolate reductase C677T polymorphism with carotid intima media thickness among South Asian, Chinese and European Canadians. Atherosclerosis 2005; 176:361-70. [PMID: 15380460 DOI: 10.1016/j.atherosclerosis.2004.06.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 05/13/2004] [Accepted: 06/01/2004] [Indexed: 11/19/2022]
Abstract
BACKGROUND Few studies have evaluated the associations of plasma homocysteine concentration, the methylenetetrahydrofolate reductase (MTHFR) C677T genotype and B vitamin concentration with intima media thickness (IMT) in multiethnic populations. METHODS In the Study of Health Assessment and Risk in Ethnic groups (SHARE), we measured carotid IMT, fasting serum folate, serum B12, plasma pyridoxal-5'-phosphate (PLP) and plasma homocysteine and determined the MTHFR C677T genotype in a cross-sectional study of 818 South Asian, Chinese and European Canadians without previous history of CVD, cancer or diabetes during 1996-1998. RESULTS Plasma homocysteine was inversely related to serum folate, serum B12, plasma PLP, B vitamin supplement use and Chinese ethnicity, and was positively associated with hypertension, smoking, IMT, MTHFR 677T/T genotype and South Asian ethnicity. Although ethnicity was not a statistically significant modifier, among carriers of the MTHFR 677T/T genotype with serum folate < or =14 nmol/L compared to >14 nmol/L, plasma homocysteine was significantly higher among South Asians (50.9% increase, P < 0.001) and Europeans (52.4% increase, P < 0.001) but not Chinese (11.0% increase, P > 0.05). Plasma homocysteine > 11.7 micromol/L was associated with a 5.9% (95% CI: 1.9%, 10.0%) increase in IMT (approximately 0.04 mm) in the pooled-data analyses with similar increases noted in the ethnic-specific analyses. The 677T/T genotype was not associated with a significant change in IMT in the pooled-data analyses (2.7%; 95% CI: -1.7%, 7.2%) nor in ethnic-specific analyses compared to other genotypes, although there were only 63 677T/T homozygotes. CONCLUSION The combination of lower serum folate and the MTHFR 677T/T genotype is associated with increased plasma homocysteine among South Asians and Europeans, but the association is not evident among Chinese possibly because their serum folate may not have been low enough to compromise MTHFR activity. Plasma homocysteine > 11.7 micromol/L appears to be associated with a clinically important increase in IMT.
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Affiliation(s)
- Linda E Kelemen
- Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN, USA.
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91
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Sievenpiper JL, Arnason JT, Leiter LA, Vuksan V. Decreasing, Null and Increasing Effects of Eight Popular Types of Ginseng on Acute Postprandial Glycemic Indices in Healthy Humans: The Role of Ginsenosides. J Am Coll Nutr 2004; 23:248-58. [PMID: 15190050 DOI: 10.1080/07315724.2004.10719368] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND It is unclear whether other ginseng sources can replicate the glycemic-lowering efficacy observed previously with American ginseng and whether ginsenosides are mediators. We assessed the effect of eight popular ginseng types on postprandial plasma glucose (PG) and insulin (PI) indices, linking effects to ginsenoside profiles. METHODS Using a double-blind, randomized, multiple-crossover design, 12 healthy participants (gender: 6M:6F, age: 34 +/- 3 y, BMI: 25.8 +/- 1.2 kg/m(2)) received 10 3g treatments: American, American-wild, Asian, Asian-red, Vietnamese-wild, Siberian, Japanese-rhizome, and Sanchi ginsengs and two placebos. Each treatment was given 40-minutes before a 75g-oral-glucose-tolerance-test (75g-OGTT) with blood drawn at -40, 0, 15, 30, 45, 60, 90, 120-minutes. HPLC-UV analysis quantified seven principal ginsenosides. RESULTS Two-factor analysis showed the main effects of ginseng-type and time were significant for PG and PI, with an interaction for PG (p < 0.05). Subsequent one-factor analysis showed an effect of ginseng-type on 90-min-PG and 90-min-PI (p < 0.05). This was reflected in effects on peak-PG, area under the curve (AUC)-PG and AUC-PI (p < 0.05). But the effect on 90-min-PI and AUC-PI were significant (p < 0.05) only in overweight participants (BMI > 25 kg/m(2), n = 6). Planned comparisons with placebo showed a tendency for American ginseng and Vietnamese ginseng to lower 90-min-PG (p < 0.06), while Asian ginseng raised peak-PG and AUC-PG, American-wild ginseng raised 120-min-PG, and Siberian ginseng raised 90-min-PG, 120-min-PG, and AUC-PG (p < 0.05). Stepwise-multiple-regression assessed the protopanaxadiol:protopanaxatriol (PPD:PPT)-ginsenoside ratio as the sole predictor (p < 0.05) for 90-min-PG (beta = -0.43, r(2) = 0.072), AUC-PG (beta = -0.25, r(2) = 0.06), 90-min-PI (beta = -0.26, r(2) = 0.065), AUC-PI (beta = -0.20, r(2) = 0.04). CONCLUSIONS Ginseng has variable glycemic effects, in which the PPD:PPT-ginsenoside ratio might be involved. But the low variance explained suggests the involvement of other unmeasured ginsenoside or non-ginsenoside components.
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Affiliation(s)
- John L Sievenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, and Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, ON, Canada
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92
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Affiliation(s)
- John L Sievenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto and Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada
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93
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Sievenpiper JL, Arnason JT, Vidgen E, Leiter LA, Vuksan V. A systematic quantitative analysis of the literature of the high variability in ginseng (Panax spp.): should ginseng be trusted in diabetes? Diabetes Care 2004; 27:839-40. [PMID: 14988315 DOI: 10.2337/diacare.27.3.839-a] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Sievenpiper JL, Arnason JT, Leiter LA, Vuksan V. Null and Opposing Effects of Asian Ginseng (Panax ginsengC.A. Meyer) on Acute Glycemia: Results of Two Acute Dose Escalation Studies. J Am Coll Nutr 2003; 22:524-32. [PMID: 14684758 DOI: 10.1080/07315724.2003.10719331] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE We have repeatedly reported that a batch of American ginseng with a specific ginsenoside (glycosidal saponin) profile decreases acute postprandial glycemia. We investigated whether Asian ginseng is able to replicate this glycemia-lowering efficacy in two separate acute dose escalation studies. METHODS Each study was conducted in a separate sample of 11 healthy subjects (gender: 8M:3F and 6M:5F, age: 29 +/- 2y and 27 +/- 3y, BMI: 28.5 +/- 2.1 kg/m(2) and 26.9 +/- 1.4 kg/m(2)) using a randomized, single-blind, placebo-controlled, multiple-crossover design. Treatments consisted of 0 (placebo), 1, 2, and 3 g of Asian ginseng for the first study and 0 (placebo), 3, 6, and 9 g Asian ginseng for the second study administered 40 minutes before a 75g-OGTT protocol with blood drawn at -40, 0, 15, 30, 45, 60, 90, and 120 minutes. Ginsenosides were analyzed by HPLC-UV. RESULTS Neither the main effect of pooled-treatment, nor dose, nor either factors interaction with time was significant for incremental plasma glucose and insulin. But the diagnostically and therapeutically relevant two-hour plasma glucose (2h-PG) value was significantly higher for pooled Asian ginseng treatment than placebo (5.46 +/- 0.31 versus 4.99 +/- 0.30 mmol/L, p = 0.050). Ginsenoside analyses showed that the Asian ginseng contained up to 96% lower and sevenfold higher quantities of various ginsenosides and their ratios than our previous efficacious batch of American ginseng. CONCLUSIONS Asian ginseng showed both null and opposing effects on indices of acute postprandial plasma glucose and insulin. This is in contrast to our findings with American ginseng. One explanation may be the marked ginsenoside differences. Practitioners and consumers should be aware of ginseng's variable effects.
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Affiliation(s)
- John L Sievenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, #6 138-61 Queen Street East, Toronto, Ontario M5C 2T2, CANADA
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95
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Kelemen LE, Anand SS, Vuksan V, Yi Q, Teo KK, Devanesen S, Yusuf S. Development and evaluation of cultural food frequency questionnaires for South Asians, Chinese, and Europeans in North America. J Am Diet Assoc 2003; 103:1178-84. [PMID: 12963948 DOI: 10.1016/s0002-8223(03)00985-4] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We developed three ethnic food frequency questionnaires (FFQs) to characterize the diets of South Asian, Chinese, and European immigrants. FFQs were developed from foods reported in the diet records and recalls of 29 South Asians, 25 Chinese, and 20 Europeans participating in a pilot study from 1995-1996 in Hamilton, Ontario, Canada. The FFQ and a seven-day diet record were then administered to 342 South Asians, 317 Chinese, and 346 Europeans participating in the Study of Health Assessment and Risk in Ethnic groups (SHARE) in three Canadian centers from 1996-1998. For FFQ validation, a subset of these participants completed a second seven-day diet record and second FFQ 8 to 10 months later. The FFQ generally underestimated macronutrient and overestimated micronutrient intake compared with the records. Consumption of most macronutrients was lower among South Asians. Energy-adjusted deattenuated correlation coefficients between the records and second FFQ ranged from 0.32 to 0.73 (South Asians), 0.17 to 0.84 (Chinese), and 0.30 to 0.83 (Europeans). The FFQs generally performed well and will be used to investigate diet-disease relations in SHARE. Lower correlations for dietary fats among Chinese persons (0.17 to 0.31) may be improved with more direct questions on the FFQ regarding brand, type, and amount of oil consumed in stirfry servings.
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Affiliation(s)
- Linda E Kelemen
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
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Jenkins DJA, Kendall CWC, Marchie A, Jenkins AL, Connelly PW, Jones PJH, Vuksan V. The Garden of Eden—plant based diets, the genetic drive to conserve cholesterol and its implications for heart disease in the 21st century. Comp Biochem Physiol A Mol Integr Physiol 2003; 136:141-51. [PMID: 14527636 DOI: 10.1016/s1095-6433(02)00345-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is likely that plant food consumption throughout much of human evolution shaped the dietary requirements of contemporary humans. Diets would have been high in dietary fiber, vegetable protein, plant sterols and associated phytochemicals, and low in saturated and trans-fatty acids and other substrates for cholesterol biosynthesis. To meet the body's needs for cholesterol, we believe genetic differences and polymorphisms were conserved by evolution, which tended to raise serum cholesterol levels. As a result modern man, with a radically different diet and lifestyle, especially in middle age, is now recommended to take medications to lower cholesterol and reduce the risk of cardiovascular disease. Experimental introduction of high intakes of viscous fibers, vegetable proteins and plant sterols in the form of a possible Myocene diet of leafy vegetables, fruit and nuts, lowered serum LDL-cholesterol in healthy volunteers by over 30%, equivalent to first generation statins, the standard cholesterol-lowering medications. Furthermore, supplementation of a modern therapeutic diet in hyperlipidemic subjects with the same components taken as oat, barley and psyllium for viscous fibers, soy and almonds for vegetable proteins and plant sterol-enriched margarine produced similar reductions in LDL-cholesterol as the Myocene-like diet and reduced the majority of subjects' blood lipids concentrations into the normal range. We conclude that reintroduction of plant food components, which would have been present in large quantities in the plant based diets eaten throughout most of human evolution into modern diets can correct the lipid abnormalities associated with contemporary eating patterns and reduce the need for pharmacological interventions.
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Affiliation(s)
- David J A Jenkins
- Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, 61 Queen Street East, Ont., M5C 2T2, Toronto, Canada
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Sievenpiper JL, Arnason JT, Leiter LA, Vuksan V. Variable effects of American ginseng: a batch of American ginseng (Panax quinquefolius L.) with a depressed ginsenoside profile does not affect postprandial glycemia. Eur J Clin Nutr 2003; 57:243-8. [PMID: 12571655 DOI: 10.1038/sj.ejcn.1601550] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND We have repeatedly reported that American ginseng (AG) with a specific ginsenoside profile significantly decreases postprandial glycemia. Whether this effect is reproducible using AG with a different profile is unknown. We therefore investigated the effect of a different batch of AG on glycemia following a 75 g oral glucose tolerance test (OGTT). METHODS Using a randomized, single blind design, 12 normal subjects (six males and six females, aged 31+/-3 y, body mass index (BMI) 28+/-2 kg/m(2)) received 6 g AG or placebo 40 min before a 75 g OGTT. The protocol followed the guidelines for the OGTT, with venous blood samples drawn at -40, 0, 15, 30, 45, 60, 90 and 120 min. Ginsenosides in the AG were assessed by established methods for HPLC-UV. RESULTS Repeated measures analysis of variance demonstrated that there was no significant effect of the AG on incremental plasma glucose (PG) or insulin (PI) or their areas under the curve Indices of insulin sensitivity (insulin sensitivity index (ISI)) and release (deltaPI(30-0)/deltaPG(30-0)) calculated from the OGTT were also unaffected. The AG contained 1.66% total ginsenosides, 0.90% (20S)-protopanaxadiol (PPD) ginsenosides, and 0.75% (20S)-protopanaxatriol (PPT) ginsenosides, with the following key ratios: PPD:PPT of 1.2, Rb(1):Rg(1) of 8.1, and Rb(2):Rc of 0.18. CONCLUSIONS The present batch of AG was unable to reproduce the postprandial hypoglycemic effects we observed previously. Possible explanations for this discrepancy include marked decrements in total ginsenosides and the key ratios PPD:PPT, Rb(1):Rg(1), and Rb(2):Rc. These data suggest that the ginsenoside profile of AG might play a role in its hypoglycemic effects. The involvement of other components cannot, however, be precluded.
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Affiliation(s)
- J L Sievenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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98
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Gerstein HC, Anand S, Yi QL, Vuksan V, Lonn E, Teo K, Malmberg K, McQueen M, Yusuf S. The relationship between dysglycemia and atherosclerosis in South Asian, Chinese, and European individuals in Canada: a randomly sampled cross-sectional study. Diabetes Care 2003; 26:144-9. [PMID: 12502671 DOI: 10.2337/diacare.26.1.144] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Raised glucose levels extending from normal into the diabetic range (dysglycemia) are an emerging risk factor for clinical cardiovascular events. The relationship between dysglycemia and atherosclerosis (AS) in the general population and in different ethnic groups remains controversial. RESEARCH DESIGN AND METHODS Glucose tolerance, HbA1c, other metabolic risk factors for AS, and carotid mean maximal intimal media thickness were assessed in a random sample of 979 Canadians of South Asian, Chinese, and European descent. RESULTS The age and sex-adjusted intimal medial thickness increased 0.026 mm for every 0.9% increase in HbA1c in all participants (P < 0.0001) and in those of South Asian (P = 0.018), Chinese (P = 0.002), and European (P < 0.0001) descent. This progressive curvilinear relationship was most apparent at HbA1c levels >5.7%. The HbA1c-AS relationship persisted after adjustment for ethnicity, age, sex, diabetes status, abdominal obesity, insulin resistance, insulin secretion, fasting free fatty acids, blood pressure, and/or dyslipidemia (P < 0.004). Both diabetes (P = 0.002) and HbA1c (P < 0.0001) were determinants of the intimal medial thickness when included in separate statistical models. When included together in a single model, HbA1c (P < 0.0001) but not diabetes (P = 0.6) was a significant determinant. CONCLUSIONS The degree of AS is related to the level of HbA1c irrespective of diabetes status and independent of abdominal obesity and other markers of the metabolic syndrome. This progressive relationship between HbA1c and AS was observed within different ethnic groups.
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Affiliation(s)
- Hertzel C Gerstein
- McMaster University and the Population Health Research Institute, Hamilton, Ontario, Canada.
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Abstract
Current dietary guidelines of the American Diabetes Association emphasize the importance of minimizing risk factors for cardiovascular disease while maximizing diabetes control. Potential advantages are seen for increased monounsaturated fat intake, but only the quantity rather than the quality of the carbohydrate is considered important. However, review of the carbohydrate issue suggests that many cultures now at high risk of diabetes originally consumed starchy staples higher in fiber and with a lower glycemic index than eaten currently. Furthermore, diets high in cereal fiber have been associated with improved glycemic control, and low glycemic index diets resulted in reduction in glycosylated proteins in type 1 and 2 diabetes. Finally, large cohort studies have demonstrated beneficial effects of cereal fiber and low glycemic index carbohydrate foods in reducing the risk both for diabetes and cardiovascular disease. The effect of insoluble cereal fiber is not readily explained, but a low glycemic index may result from a slower rate of carbohydrate absorption. Increased meal frequency as a model for reducing the rate of carbohydrate absorption has been shown to reduce day-long glucose and insulin levels in type 2 diabetes and reduce serum lipids in nondiabetic subjects. Therefore, there appears to be a potential role for low glycemic index, high-cereal fiber foods for prevention and treatment of diabetes. Both the nature of the dietary fat and the carbohydrate should be considered as potentially modifiable factors that together with weight control and exercise may play a role in diabetes and cardiovascular disease prevention and treatment.
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Affiliation(s)
- David J A Jenkins
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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Jenkins AL, Jenkins DJA, Zdravkovic U, Würsch P, Vuksan V. Depression of the glycemic index by high levels of beta-glucan fiber in two functional foods tested in type 2 diabetes. Eur J Clin Nutr 2002; 56:622-8. [PMID: 12080401 DOI: 10.1038/sj.ejcn.1601367] [Citation(s) in RCA: 237] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2000] [Revised: 10/12/2001] [Accepted: 10/17/2001] [Indexed: 11/08/2022]
Abstract
OBJECTIVES To determine the extent to which beta-glucan reduces the glycemic index (GI) of oat products and whether high levels of beta-glucan impair palatability. DESIGN The study design was an open-label, randomized cross-over study with six treatment segments. SETTING Free-living outpatients. SUBJECTS Sixteen volunteers with type 2 diabetes (10 men, six women, 61+/-2 y, body mass index 29+/-2 kg/m(2), HbA1c 7.4+/-0.4%) were recruited from the St Michael's Hospital diabetes clinic. INTERVENTIONS Volunteers were given, in random order, 50 g available carbohydrate portions of: white bread; a commercial oat bran breakfast cereal (4.4 g% beta-glucan); and a prototype beta-glucan-enriched breakfast cereal and bar, both high in beta-glucan (8.1 and 6.5 g% beta-glucan, respectively) and sweetened with fructose. Capillary blood samples were taken fasting and then 30, 60, 90, 120, 150 and 180 min after the start of the meal. Palatability was recorded using two different methods. RESULTS The glycemic indices of the prototype beta-glucan cereal (mean+/-s.e.m.; 52+/-5) and beta-glucan bar (43+/-4.1) were significantly lower than the commercial oat bran breakfast cereal (86+/-6) and white bread (100; P<0.05). All foods were highly palatable and not significantly different. It was found that the GI of the test foods used in this study decreased by 4.0+/-0.2 units per gram of beta-glucan compared to our estimate of 3.8+/-0.6 for studies reported in the literature. CONCLUSION Addition of beta-glucan predictably reduces the GI while maintaining palatability. In a 50 g carbohydrate portion each gram of beta-glucan reduces the GI by 4 units, making it a useful functional food component for reducing postprandial glycemia. SPONSORSHIP Nestec, Switzerland.
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Affiliation(s)
- A L Jenkins
- Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada
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