The association of diet and thrombotic risk factors in healthy male vegetarians and meat-eaters

The association between meat intake and the risk of coronary heart disease in Korean men using the Framingham risk score: A prospective cohort study

BACKGROUND AND AIMS

Research suggests that meat intake may increase the risk of coronary heart disease (CHD), but most studies take place in Western countries, where the types and amount of meat products consumed differ from those in Asian countries. We aimed to identify the association between meat intake and CHD risk in Korean male adults, using the Framingham risk score.

METHODS AND RESULTS

We used data from the Korean Genome and Epidemiology Study (KoGES) Health Examinees (HEXA) study, including 13,293 Korean male adults. We estimated the association of meat intake with ≥20% 10-year CHD risk using Cox proportional hazards regression models to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). Subjects with the highest total meat intake had a 53% (model 4: HR 1.53, 95% CI 1.05-2.21) increased 10-year CHD risk compared to those with the lowest intake. Those with the highest red meat intake had a 55% (model 3: HR 1.55, 95% CI 1.16-2.06) increased 10-year CHD risk compared to those with the lowest intake. No association was observed between poultry or processed meat intake and 10-year CHD risk.

CONCLUSIONS

Consumption of total meat and red meat was associated with a higher risk of CHD in Korean male adults. Further studies are needed to provide criteria for the appropriate meat intake by meat type to reduce CHD risk.

Lipid extract from blue mussel (Mytilus edulis) improves glycemic traits in Chinese type 2 diabetic mellitus patients: a double-blind randomized controlled trial

BACKGROUND

Studies have shown that blue mussel lipid extract (BMLE) has strong anti-inflammatory activity in both rheumatoid arthritis patients and animal arthritis models. Chronic inflammation was closely related to type 2 diabetes mellitus (T2DM). Though the beneficial effects cannot be completely attributed to n-3 polyunsaturated fatty acids, the aim of this study was to investigate whether BMLE can improve glycemic traits of T2DM patients.

METHOD

In a double-blind randomized controlled trial, 133 Chinese T2DM participants were randomized to either fish oil (FO, n = 44), BMLE (n = 44), or corn oil (CO, n = 45) groups for 60 days. The participants were asked to take the corresponding oil capsules (two capsules per day, 0.8 g per capsule), which provided 1.6 g day^-1 of FO (29.9% eicosapentaenoic acid + 20.4% docosahexaenoic acid), BMLE (20.7% eicosapentaenoic acid + 26.7% docosahexaenoic acid), or CO (53.5% linoleic acid).

RESULTS

The fasting serum concentration of insulin (P = 0.005) and the homeostasis model of insulin resistance (P = 0.026) were significantly decreased in the BMLE group, whereas no significant change was found in the FO or CO groups. There was no significant difference between groups on serum glycosylated hemoglobin. Tumor necrosis factor-α was significantly decreased in the BMLE group (P = 0.003), but not in the FO or CO groups. A significant decrease of interleukin-1β was observed in the BMLE and CO groups (P = 0.004 and P = 0.011 respectively), but not in the FO group. The total cholesterol was significantly decreased in the BMLE and CO groups (P < 0.001 and P < 0.001 respectively), but not in the FO group. Triacylglycerol was significantly decreased in the BMLE group (P = 0.007), but not in the FO or CO groups. High-density lipoprotein cholesterol was significantly lower in the BMLE and CO groups than in the FO group (P = 0.003).

CONCLUSION

Blue mussel lipid supplements improved glycemic traits, inflammatory cytokines, and lipids profile in Chinese T2DM patients (Chinese Clinical Trial Registration number: ChiCTR1900025617). © 2022 Society of Chemical Industry.

A vegan diet improves insulin resistance in individuals with obesity: a systematic review and meta-analysis

BACKGROUND

A vegan diet has benefits on weight reduction and on the parameters of glucose and lipid metabolism. This meta-analysis aimed to investigate the efficacy of plant-based diets on insulin resistance and blood lipids in patients with obesity.

METHODS

PubMed, Embase, and the Cochrane Library were searched for available papers published up to March 2021. The primary outcome was insulin resistance which was assessed by Homeostasis Model Assessment Insulin Resistance (HOMA-IR), other metabolic parameters measures including the pre/post-diet changes in triglycerides, HDL-cholesterol, total cholesterol, LDL-cholesterol. All analyses were performed using the random-effects model.

RESULTS

Six studies (seven datasets) were included. Compared with baseline, the plant-based diet improved the HOMA-IR (SMD = 1.64, 95%CI 0.95, 2.33; I² = 91.8%, P_{heterogeneity} < 0.001), total cholesterol (SMD = 2.51, 95% CI 0.88, 4.13; I² = 98.0%, P_{heterogeneity} < 0.001), HDL-cholesterol (SMD = 1.55, 95% CI 0.66, 2.44; I² = 92.0%, P_{heterogeneity} < 0.001), and LDL-cholesterol (SMD = 2.50, 95% CI 1.30, 3.70; I² = 94.4%, P_{heterogeneity} < 0.001), but not the triglycerides (SMD = - 0.62, 95% CI - 1.92, 0.68; I² = 97.8%, P_{heterogeneity} < 0.001). The sensitivity analyses showed that the results were robust.

CONCLUSIONS

In obese individuals with insulin resistance, a vegan diet improves insulin resistance and dyslipidemia, except for triglycerides.

Nutrient Intake and Nutrition Status in Vegetarians and Vegans in Comparison to Omnivores - the Nutritional Evaluation (NuEva) Study

Introduction

In recent years, vegetarian and vegan diets became increasingly important as they are associated with beneficial health outcomes. Therefore, the NuEva study compares the impact of flexitarian, vegetarian, or vegan diets with omnivorous nutritional habits on nutrient intake and risk factors for non-communicable diseases.

Methods

A dietary protocol was kept over five days and blood and 24h urine samples were collected to examine the impact of dietary habits [omnivores, n = 65 (Median/Interquartile range: 33/17 yrs.), flexitarians, n = 70 (30/17 yrs.), ovo-lacto vegetarians, n = 65 (28/14 yrs.), vegans, n = 58 (25/10 yrs.)] on nutrient intake, nutrient concentrations in plasma, serum or 24h urine, body composition, and blood lipids.

Results

The increased exclusion of animal based foods in the diet (omnivores < flexitarians < vegetarians < vegans) is associated with a decreased intake of energy, saturated fat, cholesterol, disaccharides, and total sugar as well an increased intake of dietary fibers, beta carotene, vitamin E and K. The combined index of the B12 status (4cB12 score) in vegetarians (0.02/0.75) was lower compared to omnivores (0.34/0.58; p ≤ 0.05) and flexitarians (0.24/0.52; p ≤ 0.05). In omnivores vitamin A, vitamin E, ferritin, and the urinary excretion of selenium, iodine, and zinc were higher than in vegans (p ≤ 0.05). In contrast, vegans had the highest concentrations of biotin, folate, and vitamin C. Flexitarians, vegetarians, and vegans had a lower body weight, BMI, and body fat percentage in comparison to omnivores (p ≤ 0.05). In omnivores the concentrations on total cholesterol, total cholesterol/HDL cholesterol ratio, LDL cholesterol, LDL cholesterol/HDL cholesterol ratio, apolipoprotein B, and apolipoprotein B/ apolipoprotein A1 ratio were higher than in vegetarians and vegans (p ≤ 0.05).

Conclusion

The NuEva study confirms the position of the Academy of Nutrition and Dietetics that adequately planned vegetarian diets are healthy, nutritionally adequate, and may provide health benefits in the prevention and treatment of non-communicable diseases. Nevertheless, critical nutrients were identified for all groups studied. This highlights the need to develop individual nutritional concepts to ensure an adequate nutrient intake.

Global thrombosis test for assessing thrombotic status and efficacy of antithrombotic diet and other conditions

Because of the high mortality from myocardial infarction and stroke, there is a great demand for finding novel methods of diagnosis, prevention and treatment of these diseases. Most of the current tests measure important determinants of thrombosis such as platelet function, coagulation and fibrinolysis in isolation; therefore, a global test measuring the actual thrombotic status would be more useful in clinical conditions. We obtained considerable experience by using the global thrombosis test, which determines the actual thrombotic status by taking into account the measured platelet reactivity, coagulation and fibrinolytic activities. In animal experiments, we found significant correlation between the ex vivo global thrombosis test measurements and the in vivo thrombotic status. The published evidence for the benefit of an antithrombotic diet with regular physical exercise is also described.

There is a great concern in the general population how to detect the risk of thrombotic events and prevent the high mortality from stroke, myocardial infarction, sudden death and cancer-associated thrombosis. Our experience on antithrombotic fruits and vegetables intake and regular exercise assessed by the global thrombosis test suggested a potentially unique way of preventing these life-threatening diseases. In addition, global thrombosis testing may offer some benefit in detecting risk of thrombotic of forthcoming thrombotic events in cancer and COVID-19 virus-infected patients.

Red meat and processed meat consumption and the risk of dyslipidemia in Korean adults: A prospective cohort study based on the Health Examinees (HEXA) study

BACKGROUND AND AIMS

There has been conflicting results on the effect of red meat and processed meat intake on the dyslipidemia risk. Moreover, studies in Asian population with lower meat intake than the Western population are lacking. In this study, we aimed to investigate the association between red and processed meat consumption and the dyslipidemia risk by sex among Koreans.

METHODS AND RESULTS

A total of 20,407 participants from a prospective cohort were divided into quintiles according to their red meat consumption and tertiles according to their processed meat consumption based on the validated semi-quantitative food frequency questionnaire. The Cox proportional hazards regression analysis was used to estimate the relative risk and 95% confidence interval of dyslipidemia according to red and processed meat consumption. Higher red meat consumption was associated with a 34% and 10% increased risk of hypercholesterolemia in both men and women, and further, a 58% and 17% increased risk of hyper-low-density lipoprotein cholesterolemia and dyslipidemia, in men, compared to the lowest consumption group. Higher processed meat consumption was associated with a 38% and 9% increased risk of hypercholesterolemia, 29% and 18% increased risk of hypertriglyceridemia, and 32% and 10% increased risk of dyslipidemia in both men and women, respectively, compared to the lowest consumption group.

CONCLUSION

The results of the present study can provide compelling evidence on Asian population that red and processed meat consumption can lead to a higher risk of dyslipidemia.

Effect of hay with or without concentrate or pellets on growth performance and meat quality of Ujimqin lambs on the Inner Mongolian Plateau

This study aimed to evaluate growth performance and meat quality of Ujimqin lambs fed native grass hay without or with concentrate (HC) or pellets. Ninety non-castrated 6-month-old male lambs of good health and similar body weight (26.83 ± 0.26 kg) were randomly divided into three groups (five lambs per cage). The average daily gain and intake of the pellets and HC groups were significantly greater (p < .05) than those in the hay group. The carcass weight, net meat mass, loin eye area, and backfat thickness were significantly greater (p < .05) in the HC groups. The intramuscular fat was significantly greater (p < .05) in the pellets and HC groups, while the shear force was significantly decreased (p < .05) in pellets and HC groups. The C16:0, C18:0, C18:1n9c, and C18:2n6 contents were significantly greater (p < .05) in the HC and pellet groups, while the C18:3n3 content was significantly greater (p < .05) in the hay group. Collectively, the present study suggested that feeding native grass hay with concentrate or pellets improved the growth in lambs.

A Study Protocol for a Parallel-Designed Trial Evaluating the Impact of Plant-Based Diets in Comparison to Animal-Based Diets on Health Status and Prevention of Non-communicable Diseases-The Nutritional Evaluation (NuEva) Study

Background and Aims: Currently, there is a continuing upward trend for plant-based lifestyles in Germany and Europe. The implementation of vegetarian and vegan lifestyles is characterized by omitting defined food groups such as fish, meat, sausage (vegetarians), or dairy products and honey (vegans). This carries the risk of an undersupply of valuable nutrients. The NuEva study is designed to examine this hypothesis and to evaluate the impact of plant-based diets on health status and disease risk.

Methods: The NuEva study is a parallel-designed trial with at least 55 participants for each diet (vegetarian, vegan, flexitarian [rare meat/sausage consumption, once or twice per week]), and participants who consume a traditional Western diet as the control group. In the screening period critical nutrients are identified for the studied diets by analysis of a broad spectrum of nutrients in the human samples (fatty acids, vitamins, minerals, trace elements, nutrient metabolites).

Results: Based on the data from the screening period, defined menu plans, ensuring an adequate nutrient intake in accordance with the nutritional guidelines are prepared for each group. The plans are adapted and personalized to individual energy requirements based on the basal metabolic rate and physical activity level. The compliance with the NuEva concept and their impact on nutrient status and cardiovascular risk factors are validated during the intervention period of the NuEva study over 1 year. To investigate the impact of the studied diets on the microbiome, feces samples are collected at the beginning and after the 12 months intervention period (follow up: 12 months).

Conclusion: The NuEva study is designed to investigate the impact of common diets on health and disease status, with focus on prevention of cardiovascular diseases. In addition, the effectiveness of the prepared nutritional coaching strategy, ensuring optimal nutrient intake in accordance with the guidelines, is validated during the intervention period of the NuEva study.

Clinical Trial Registration: Registered under ClinicalTrials.gov Identifier no. NCT03582020.

Long-term association of red meat consumption and lipid profile: A 13-year prospective population-based cohort study

OBJECTIVES

The long-term associations between red meat consumption and lipid profile are not completely known. This longitudinal study assessed the association of red meat consumption with lipid profile in healthy Iranian adults using repeated measurements of red meat intake.

METHODS

The population-based longitudinal study was conducted within the framework of the Isfahan Cohort Study on a subsample of 1376 healthy adults, aged ≥35 y, for whom complete information was available in all three phases of the study. A simplified qualitative 48-item food frequency questionnaire, blood pressure, anthropometric measurements, and fasting serum lipids and blood sugar were evaluated in three phases. Mixed-effects linear regression was applied to examine the longitudinal associations between red meat consumption and lipid profile.

RESULTS

After adjustment for potential confounders, each single-serving increase in red meat and organ meat consumption was significantly associated with an increment in triacylglycerol (β = 6.30; 95% confidence interval [CI], 3.97-8.63), total cholesterol (β = 3.03; 95% CI, 2.02-4.04), low-density lipoprotein (β = 3.40; 95% CI, 2.64-4.17), high-density lipoprotein (β = 0.60; 95% CI, 0.28-0.93), ratio of low-density to high-density lipoprotein (β = 0.03; 95% CI, 0.01-0.05), and non-high-density lipoprotein (β = 2.42; 95% CI, 1.41-3.43). However, processed meat consumption had no significant association with lipid profile.

CONCLUSIONS

Total red meat intake had a significant, direct association with lipid profile after a 13-year follow-up period in a cohort of the healthy Iranian population.

Changes in biochemical parameters by gender and time: Effect of short-term vegan diet adherence

Background

Vegetarian diets adapted for various reasons that may include religious, ethical, and health considerations have reasonable health benefits including weight loss, and favorable metabolic changes. However, studies that assessed health benefits associated with vegan diet practices during the Ethiopian Orthodox Christian (EOC) Lenten fasting remains limited. This study has, therefore, assessed how short-term vegan diet associated with metabolic traits, including weight, body mass index (BMI), circumference, blood pressure, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), through longitudinal cross-sectional study design.

Methods

Seventy-five subjects (34 females and 41 males) with a mean age of [+SD] 27.3 + 5.8 years (range, 18 and 35) took part in the study. The study followed three assessment sessions: at baseline, during the Lenten (week 7), and 7 weeks after the end of the Lenten (week 14). An automatic chemistry analyzer (Mindray, BE-2000, China) used for lipid profile analysis. We used paired sample t-test in pre and post-performance and repeated measures ANOVA with Bonferroni post hoc adjustment between time points. The statistical significance was set at p < 0.05.

Results

The EOC fasting with vegan diet induced significantly lower blood pressure, weight, BMI, TC, HDL-C, LDL-C, and TC: HDL-C ratios, during Lenten (that is vegan diet consumption), but a regain noted in these parameters 7-weeks after Lenten (that is omnivore diet). On gender differences, vegan diet associated with significantly lower blood pressure, TC, and LDL-C in females compared with age-matched male counterparts. Some methodological limitations of this study are discussed with particular reference to lack of a randomized control group and self-reported data that limit this study in establishing a causal relationship through observed associations.

Conclusions

Vegan diet consumption even for short period corroborate ideal metabolic traits, with more favorable changes noted in women than age-matched men counterparts. These findings might help to define vegetarian diets as part of religious fasting (beyond its spiritual goals) as a non-pharmacological prescription in different populations, and our findings add to growing evidence in these subjects.

Cardiometabolic risk factors in vegans; A meta-analysis of observational studies

Background

There is increasing evidence that plant based diets are associated with lower cardiovascular risk.

Objective

To evaluate effects of a vegan compared to an omnivorous diet on cardio-metabolic risk factors.

Methods

Meta-analysis of observational studies published between 1960 and June 2018 that reported one or more cardio-metabolic risk factors in vegans and controls eating an omnivorous diet were undertaken. Macro-nutrient intake and cardio-metabolic risk factors were compared by dietary pattern. The Newcastle Ottawa Scale (NOS) was used to assess the quality of each study. The inverse-variance method was used to pool mean differences. Statistical analyses were performed using RevMan software version 5•2 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen.

Results

40 studies with 12 619 vegans and 179 630 omnivores were included. From food frequency questionnaires in 28 studies, vegans compared to omnivores consumed less energy (-11%, 95% confidence interval -14 to -8) and less saturated fat (- 51%, CI -57 to -45). Compared to controls vegans had a lower body mass index (-1.72 kg/m², CI -2.30 to -1.16), waist circumference (-2.35 cm, CI -3.93 to -0.76), low density lipoprotein cholesterol (-0.49 mmol/L CI -0.62 to -0.36), triglycerides (-0.14 mmol/L, CI -0.24 to -0.05), fasting blood glucose (-0.23 mmol/, CI -0.35 to -0.10), and systolic (-2.56 mmHg, CI -4.66 to -0.45) and diastolic blood pressure (-1.33 mmHg, CI -2.67 to -0.02), p<0.0001 for all. Results were consistent for studies with < and ≥ 50 vegans, and published before and after 2010. However in several large studies from Taiwan a vegan diet was not associated with favourable cardio-metabolic risk factors compared to the control diets.

Conclusion

In most countries a vegan diet is associated with a more favourable cardio- metabolic profile compared to an omnivorous diet.

A brief history of meat in the human diet and current health implications

Anthropological investigations have confirmed many times over, through multiple fields of research the critical role of consumption of animal source foods (ASF) including meat in the evolution of our species. As early as four million years ago, our early bipedal hominin ancestors were scavenging ASFs as evidenced by cut marks on animal bone remains, stable isotope composition of these hominin remains and numerous other lines of evidence from physiological and paleo-anthropological domains. This ASF intake marked a transition from a largely forest dwelling frugivorous lifestyle to a more open rangeland existence and resulted in numerous adaptations, including a rapidly increasing brain size and altered gut structure. Details of the various fields of anthropological evidence are discussed, followed by a summary of the health implications of meat consumption in the modern world, including issues around saturated fat and omega-3 fatty acid intake and discussion of the critical nutrients ASFs supply, with particular emphasis on brain function.

Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition

BACKGROUND

Interest in vegetarian diets is growing in Italy and elsewhere, as government agencies and health/nutrition organizations are emphasizing that regular consumption of plant foods may provide health benefits and help prevent certain diseases.

METHODS AND RESULTS

We conducted a Pubmed search, up to September, 2015, for studies on key nutrients (proteins, vitamin B12, iron, zinc, calcium, vitamin D, and n-3 fatty acids) in vegetarian diets. From 295 eligible publications the following emerged: Vegetarians should be encouraged to supplement their diets with a reliable source of vitamin B12 (vitamin-fortified foods or supplements). Since the plant protein digestibility is lower than that of animal proteins it may be appropriate for vegetarians to consume more proteins than recommended for the general population. Vegetarians should also be encouraged to habitually consume good sources of calcium, iron and zinc - particularly vegetables that are low in oxalate and phytate (e.g. Brassicaceae), nuts and seeds, and calcium-rich mineral water. Calcium, iron, and zinc bioavailability can be improved by soaking, germination, and sour-dough leavening that lower the phytate content of pulses and cereals. Vegetarians can ensure good n-3 fatty acid status by habitually consuming good sources of a-linolenic acid (walnuts, flaxseeds, chia seeds, and their oils) and limiting linoleic acid intake (corn and sunflower oils).

CONCLUSIONS

Well-planned vegetarian diets that include a wide variety of plant foods, and a reliable source of vitamin B12, provide adequate nutrient intake. Government agencies and health/nutrition organizations should provide more educational resources to help Italians consume nutritionally adequate vegetarian diets.

Prospective associations of meat consumption during childhood with measures of body composition during adolescence: results from the GINIplus and LISAplus birth cohorts

BACKGROUND

Higher meat and protein intakes have been associated with increased body weight in adults, but studies evaluating body composition are scarce. Furthermore, our knowledge in adolescents is limited. This study aimed to investigate the prospective associations of intakes of different meat types, and their respective protein contents during childhood, with body composition during adolescence.

METHODS

Dietary (using food frequency questionnaires) and body composition (measured by bioelectrical impedance) data were collected from the 10- and 15-year follow-up assessments respectively, of the GINIplus and LISAplus birth cohort studies. Sex-stratified prospective associations of meat and meat protein intakes (total, processed, red meat and poultry) with fat mass index (FMI) and fat free mass index (FFMI), were assessed by linear regression models (N = 1610).

RESULTS

Among males, higher poultry intakes at age 10 years were associated with a higher FMI at age 15 years [β = 0.278 (SE = 0.139), p = 0.046]; while higher intakes of total and red meat were prospectively associated with higher FFMI [0.386 (0.143), p = 0.007, and 0.333 (0.145), p = 0.022, respectively]. Additionally in males, protein was associated with FFMI for total and red meat [0.285 (0.145) and 0.356 (0.144), respectively].

CONCLUSIONS

Prospective associations of meat consumption with subsequent body composition in adolescents may differ by sex and meat source.

Vegetarian diets and gut microbiota: important shifts in markers of metabolism and cardiovascular disease

Vegetarian diets have been associated with a lower incidence of several chronic diseases. The benefits of plant-based diets are related mainly to the improvement of metabolic parameters that can indicate risk for such diseases. Some metabolic factors, such as oxidative balance, lipid profile, and glucose homeostasis, can be improved directly by diet, but paradoxically, some characteristics of vegetarian diets may promote a negative scenario that increases the risk of certain chronic diseases. Additionally, many benefits of a vegetarian diet are mediated by the gut microbiota, members of which not only have taxonomic and functional differences but also produce diverse, specific metabolites that vary according to whether the host consumes an omnivorous or a vegetarian diet. This review examines the modulation of human metabolism and gut microbiota by vegetarian and omnivorous dietary patterns and explores how this modulation may affect the risk of cardiovascular disease.

Association of serum fatty acid and estimated desaturase activity with hypertension in middle-aged and elderly Chinese population

We aimed to investigate the cross-sectional associations of serum fatty acid (FA) and related Δ-desaturase with hypertension among 2,447 community-dwellers aged 35-79 years living in Zhejiang Province, China. Individual FA was determined in serum, Δ(5)-desaturase (D5D) and Δ(6)-desaturase (D6D) activities were indirectly estimated by FA product/precursor ratios. Participants in the highest quartile of D5D component scores (20:4n-6, 20:5n-3, 22:6n-3 and D5D) have significantly lower odds of hypertension compared with individuals in the lowest (multivariate-adjusted odds ratio (OR) = 0.68, 95% CI: 0.46-0.98). When further stratified by gender, high D5D component scores were significantly associated with lower odds of hypertension in women (OR = 0.53, 95% CI: 0.35-0.80), but not in men (OR = 0.78, 95% CI: 0.52-1.18). Multivariate-adjusted prevalent OR for an interquartile increment of individual FA and estimated desaturase was 1.27 (95% CI: 1.08-1.50) for 16:0, 1.15 (95% CI: 1.01-1.30) for 16:1n-7, 0.89 (95% CI: 0.80-0.99) for 22:6n-3, 1.32 (95% CI: 1.01-1.72) for D6D (18:3n-6/18:2n-6), and 0.74 (95% CI: 0.56, 0.98) for D5D (20:4n-6/20:3n-6). Present findings suggested that high serum 22:6n-3 and D5D as well as low 16:0, 16:1n-7 and D6D were associated with a low prevalence of hypertension in this Chinese population.

Exploratory serum fatty acid patterns associated with blood pressure in community-dwelling middle-aged and elderly Chinese

Background

Epidemiological studies have assessed relationships between circulating levels of fatty acid (FA) and blood pressure (BP), and their results remain controversial. Nevertheless, data are sparse on serum FA as biomarker and BP in China. The aim of the study was to investigate the association between serum FA and BP in Chinese populations.

Methods

We conducted a cross-sectional study nested within a community-based cohort of 2447 Chinese participants aged 35–79 years who completed a baseline assessment between October 2012 and April 2013. Baseline assessment included the collection of fasting blood samples, anthropometric measurements and a personal interview using a validated questionnaire. Serum FA was determined by gas-liquid chromatography. Exploratory factor analyses were employed to identify FA-factor as a reflection of serum FA pattern. A multiple regression model was conducted to estimate adjusted mean of BP with 95 % confidence interval (CI) by tertile groups of the generated FA-factor scores.

Results

Hypertensive patients have significantly higher serum 14:0, 16:0, 16:1n-7, 18:3n-6, 20:3n-6 and Δ⁶-desaturase index (18:3n-6/18:2n-6) as well as lower 18:2n-6, 22:6n-3 and Δ⁵-desaturase index (20:4n-6/20:3n-6) compared with normotensive participants. Factor 1 (low linoleic acid/high saturated FA pattern: 14:0, 16:0, 16:1n-7, 18:2n-6, 18:3n-6, 20:3n-6) and Factor 2 (n-3 PUFA pattern: 20:5n-3, 22:5n-3, 22:6n-3, 18:1n-9) were identified as indicators of the serum FA pattern. After adjustment for age, gender, body mass index, hypertension treatment, smoking, alcohol intake, education, profession, exercise habit, salt intake, family history of hypertension, heart rate, blood lipids and fasting blood-glucose levels, per a standard deviation (SD) increment of Factor 1 scores was associated with an increment of 2.44 (95 % CI: 1.73, 3.15) mm Hg for systolic BP, whereas per a SD increment of Factor 2 scores was associated with a reduction of 1.40 (95 % CI: 0.80, 2.04) mm Hg for diastolic BP.

Conclusions

The serum FA pattern characterized by low proportions of 14:0, 16:0, 16:1n-7 and 18:3n-6 as well as high 18:2n-6 and 22:6n-3 was beneficially associated with BP levels in this Chinese population. This evidence well supports the current dietary recommendations in the communities to replace saturated fat with polyunsaturated fat.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-016-0226-3) contains supplementary material, which is available to authorized users.

Inverse Association of Serum Docosahexaenoic Acid With Newly Diagnosed Hypertension: A Community-based Case-control Study

Observational studies on circulating fatty acid (FA) and primary prevention of hypertension have yielded inconsistent results, and the association among the Chinese population is not fully clear. The aim of the study was to discern important FAs that can discriminate hypertensive patients from normotensive persons, and investigate associations between the important FAs and risk of hypertension.We conducted a case-control study nested within a community-based cohort of 2447 Chinese participants aged 35 to 79 years who completed a baseline assessment between October 2012 and April 2013. In all, 480 patients with newly diagnosed hypertension were identified at baseline and 480 normotensive individuals were randomly selected as matched normotensive controls. Controls were individually matched to cases by age (±2 y), sex, and recruitment center, with a 1:1 case-to-control ratio. Serum FA profile was compared between cases and controls by orthogonal partial least squares-discriminant analyses. Odds ratio (OR) with 95% confidence interval (CI) for newly diagnosed hypertension was estimated by a conditional logistical analysis.After adjustment for body mass index, education, profession, family history of hypertension, salt intake, heart rate, blood lipids, and fasting glucose levels, serum FA profile in hypertensive patients was typically characterized by higher 16:0 and 16:1n-7, and lower 18:2n-6 and 22:6n-3, compared with normotensive controls. Docosahexaenoic acid (22:6n-3) and palmitoleic acid (16:1n-7) were identified as the important FA contributing most to the intergroup separations. When comparing the highest and lowest quartile of FA composition, newly diagnosed hypertension was negatively associated with 22:6n-3 (OR 0.65; 95% CI, 0.45-0.93; P for trend = 0.02), but positively associated with 16:1n-7 (OR 2.14; 95% CI, 1.46-3.12; P for trend < 0.001). The associations remained pronounced after multiple adjustments and in further stratified analyses.In distinguishing hypertensive patients and normotensive persons, 22:6n-3 was considered as an important n-3 FA. Increased serum proportion of 22:6n-3 was associated with decreased odds of newly diagnosed hypertension, which suggests that high levels of 22:6n-3 in serum or perhaps in diet may be beneficial for prevention of hypertension in the Chinese population.

Effects of Vegetarian Diets on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Vegetarian diets exclude all animal flesh and are being widely adopted by an increasing number of people; however, effects on blood lipid concentrations remain unclear. This meta-analysis aimed to quantitatively assess the overall effects of vegetarian diets on blood lipids.

METHODS AND RESULTS

We searched PubMed, Scopus, Embase, ISI Web of Knowledge, and the Cochrane Library through March 2015. Studies were included if they described the effectiveness of vegetarian diets on blood lipids (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride). Weighted mean effect sizes were calculated for net changes by using a random-effects model. We performed subgroup and univariate meta-regression analyses to explore sources of heterogeneity. Eleven trials were included in the meta-analysis. Vegetarian diets significantly lowered blood concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol, and the pooled estimated changes were -0.36 mmol/L (95% CI -0.55 to -0.17; P<0.001), -0.34 mmol/L (95% CI -0.57 to -0.11; P<0.001), -0.10 mmol/L (95% CI -0.14 to -0.06; P<0.001), and -0.30 mmol/L (95% CI -0.50 to -0.10; P=0.04), respectively. Vegetarian diets did not significantly affect blood triglyceride concentrations, with a pooled estimated mean difference of 0.04 mmol/L (95% CI -0.05 to 0.13; P=0.40).

CONCLUSIONS

This systematic review and meta-analysis provides evidence that vegetarian diets effectively lower blood concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol. Such diets could be a useful nonpharmaceutical means of managing dyslipidemia, especially hypercholesterolemia.

Fish-Free Diet in Patients with Phenylketonuria Is Not Associated with Early Atherosclerotic Changes and Enhanced Platelet Activation

Background and Purpose

Since patients with phenylketonuria (PKU) have to follow a lifelong restriction of natural protein to lower phenylalanine-intake, they never eat fish. This diet may lead to a chronic deficit of omega-3 and omega-6 fatty acids with the risk of early atherosclerotic changes. The aim of the study was to analyse the fatty acid profile of PKU patients and to correlate the results with surrogate markers of early atherosclerotic changes [enhanced carotid intima media thickness (CIMT) and ß-stiffness index] and platelet activation.

Methods

In 43 PKU patients and in 58 healthy controls we prospectively examined the fatty acid profile, CIMT, ß-stiffness index and platelet activation (flow cytometric determination of markers of platelet activation). CIMT was measured bilaterally by ultrasound. CIMT _mean was defined as the mean value of the sum of CIMT _left and CIMT _right.

Results

Despite of lower HDL-cholesterol and higher triglyceride concentrations in the PKU group, there was no significant difference in the omega-6 or omega-3 fatty acid profile, CIMT, ß-stiffness index between both groups. Platelet activation was not enhanced in the PKU group.

Conclusions

Fish-free diet does not induce early atherosclerotic changes or enhanced platelet activation in PKU patients.

Lipid extract from hard-shelled mussel (Mytilus coruscus) improves clinical conditions of patients with rheumatoid arthritis: a randomized controlled trial

Studies have suggested a lipid extract from hard-shelled mussel (Mytilus coruscus) (HMLE) possessed strong anti-inflammatory activity in arthritis model of rats. This study investigated whether HMLE could improve clinical conditions of rheumatoid arthritis patients. Fifty rheumatoid arthritis patients (28–75 years) were randomly assigned to receive HMLE capsules or receive placebo capsules for 6 months. Forty-two subjects and 50 subjects were included in per-protocol and intention-to-treat analysis, respectively. Significant differences in changes on disease activity score (DAS28) and clinical disease activity index (CDAI) after 6-month intervention (p < 0.01) were observed in both analyses with more evident efficacy shown in per-protocol population (∆DAS28 = 0.47; ∆CDAI = 4.17), which favored the benefits of the HMLE group. TNF-α (tumor necrosis factor α), interleukin (IL)-1β and PGE₂ (prostaglandin E2) but not IL-6, were significantly decreased in both groups, and the decrements were much larger in the HMLE group for TNF-α and PGE₂ after 6 months from baseline (p < 0.05). IL-10 was significantly increased in both groups and the change was much more evident in the HMLE group (p < 0.05). In conclusion, HMLE exhibited benefits for the clinical conditions of rheumatoid patients in relation to improvement in the balance between pro- and anti-inflammatory factors, which indicated its potential to serve as adjunctive treatment for rheumatoid arthritis. (ClinicalTrials.gov NCT02173587).

Omega-3 polyunsaturated fatty acids and vegetarian diets

While intakes of the omega-3 fatty acid α-linolenic acid (ALA) are similar in vegetarians and non-vegetarians, intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are low in vegetarians and virtually absent in vegans. Plasma, blood and tissue levels of EPA and DHA are lower in vegetarians than in non-vegetarians, although the clinical significance of this is unknown. Vegetarians do not exhibit clinical signs of DHA deficiency, but further research is required to ascertain whether levels observed in vegetarians are sufficient to support optimal health. ALA is endogenously converted to EPA and DHA, but the process is slow and inefficient and is affected by genetics, sex, age and dietary composition. Vegetarians can take practical steps to optimise conversion of ALA to EPA and DHA, including reducing intake of linoleic acid. There are no official separate recommendations for intake of fatty acids by vegetarians. However, we suggest that vegetarians double the current adequate intake of ALA if no direct sources of EPA and DHA are consumed. Vegetarians with increased needs or reduced conversion ability may receive some advantage from DHA and EPA supplements derived from microalgae. A supplement of 200-300 mg/day of DHA and EPA is suggested for those with increased needs, such as pregnant and lactating women, and those with reduced conversion ability, such as older people or those who have chronic disease (eg, diabetes).

Serum phospholipid omega-3 polyunsaturated fatty acids and insulin resistance in type 2 diabetes mellitus and non-alcoholic fatty liver disease

AIMS

To investigate the relationship between serum phospholipid omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and insulin resistance (IR) in patients with type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD).

METHODS

51 patients with T2DM and NAFLD (T2DM+NAFLD group), 50 with T2DM alone (T2DM group), 45 with NAFLD alone (NAFLD group), and 42 healthy control subjects (NC group) were studied. Serum ω-3 PUFA profiles were analyzed by gas chromatography, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and serum lipid concentrations were measured. Insulin resistance was assessed by the homeostasis model assessment method (HOMA-IR).

RESULTS

HOMA-IR levels were higher in the T2DM+NAFLD group than in the T2DM, NAFLD and NC groups (p<0.05), as were ALT, AST, GGT, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations (p<0.05). Conversely, serum ω-3 PUFA levels were significantly lower in the T2DM+NAFLD group than in the other groups (p<0.05). The ω-3 PUFA level was negatively correlated with HOMA-IR, TC, LDL-C and TG.

CONCLUSIONS

Serum phospholipid ω-3 PUFA levels were significantly decreased in patients with T2DM and NAFLD, and were negatively related with insulin resistance. Thus, reduced ω-3 PUFAs may play an important role in the development of T2DM and NAFLD.

Comparison of vegetarian diets and omnivorous diets on plasma level of HDL-c: a meta-analysis

Low plasma level of high density lipoprotein cholesterol (HDL-c) was an independent risk factor for cardio vascular disorder, and associated with poor outcomes in pulmonary arterial hypertension. To compare the effects of vegetarian diets and omnivorous diets on HDL-c in plasma, we identified cross-sectional and cohort studies related to HDL-c listed on PubMed and ISI Web of Knowledge as well as the corresponding references (until Nov, 2013). Twelve studies with a total of 4177 individuals were selected for meta-analysis. This meta-analysis indicates that vegetarian diets did not alter plasma HDL-c concentrations, as it wasn’t initially expected by the authors [Standardized Mean Difference (SMD) = 0.02 mmol/l; 95% confidence interval (CI): −0.19 to 0.22 mmol/l]. In Asia and Latin America countries, no significant differences in HDL-c levels between vegetarians and omnivores were found (SMD = −0.09 mmol/l; 95% CI: −0.43 to 0.25 mmol/l). In Europe and North America countries, the plasma level of HDL-c was also not different between the two diets (SMD = 0.09 mmol/l; 95% CI: −0.19 to 0.36 mmol/l). In light of this meta-analysis, we conclude that there is no evidence that plasma HDL-c levels differs in vegetarians and omnivores, even after adjusting for cultural circumstances.

Effect of the vegetarian diet on non-communicable diseases

A vegetarian diet generally includes plenty of vegetables and fruits, which are rich in phytochemicals, antioxidants, fiber, magnesium, vitamins C and E, Fe³⁺, folic acid and n-6 polyunsaturated fatty acid (PUFA), and is low in cholesterol, total fat and saturated fatty acid, sodium, Fe²⁺, zinc, vitamin A, B₁₂ and D, and especially n-3 PUFA. Mortality from all-cause, ischemic heart disease, and circulatory and cerebrovascular diseases was significantly lower in vegetarians than in omnivorous populations. Compared with omnivores, the incidence of cancer and type 2 diabetes was also significantly lower in vegetarians. However, vegetarians have a number of increased risk factors for non-communicable diseases such as increased plasma homocysteine, mean platelet volume and platelet aggregability compared with omnivores, which are associated with low intake of vitamin B₁₂ and n-3 PUFA. Based on the present data, it would seem appropriate for vegetarians to carefully design their diet, specifically focusing on increasing their intake of vitamin B₁₂ and n-3 PUFA to further reduce already low mortality and morbidity from non-communicable diseases.

Human evolution and diet: a modern conundrum of health versus meat consumption, or is it?

Despite negative press reports on the effect of meat and other animal-source foods (ASFs) on human health and a vocal minority who contend that humans evolved as vegetarians, scientific evidence contradicts these views. For several million years before the development of agriculture, our ancestors were heavily reliant on ASFs as a source of energy and critical substrates such as protein and long-chain omega-3 fatty acids. Numerous lines of evidence in the anthropological literature have confirmed this scenario. Studies on ASF composition and clinical trials on ASF consumption have provided clear evidence of a requirement for meat in the diet to provide nutrients essential to health, such as Vitamin B12, long-chain omega-3 fatty acids and bioavailable forms of iron and zinc. Other studies have demonstrated that lean ASFs have a role in cholesterol-lowering diets and are important for mental function. Finally, it is possible and desirable to produce meat of a lean nature that mimics the many healthy attributes of wild-game meats and, by emphasising pasture feeding over grain feeding, this can be achieved to a large extent in Australia.

Serum levels of polyunsaturated fatty acids are low in Chinese men with metabolic syndrome, whereas serum levels of saturated fatty acids, zinc, and magnesium are high

The purpose of this study was to examine the hypothesis that serum levels of phospholipid (PL) fatty acids (FA) and minerals are associated with the components of metabolic syndrome (MetS) in the Chinese population and the profiles of changes may differ from patients with MetS from Western countries. The levels of serum PL, FA, and minerals were examined in 201 subjects (52 with MetS and 149 healthy controls without any MetS components) in China. The saturated FA proportion in serum was significantly higher, whereas the proportion of total polyunsaturated FA (PUFA), n-3 and n-6 PUFA (22:6n-3: -16%, P = .006; 20:4n-6: -36%, P < .001), and estimated δ-5 desaturase were significantly lower in the MetS group compared with those that are not MetS. Subjects with MetS had higher levels of serum Zn (P = .037) and Mg (P < .001) than subjects without MetS. The proportion of n-3 PUFA was significantly negatively correlated with body mass index and waist circumference. In conclusion, serum PL FA composition and serum minerals in Chinese men with MetS differed significantly from that of healthy individuals, reflecting a decrease in n-3 and n-6 PUFA, especially 22:6n-3 and 20:4n-6, and an increase in saturated FA, magnesium, and zinc. These changes may reflect improper dietary intake in subjects with MetS, and dietary modification could be useful to prevent MetS and as an adjunctive therapy.

Chemistry behind Vegetarianism

This review summarizes the effect of a habitual vegetarian diet on clinical complications in relation to chemistry and biochemistry. Omnivores have a significantly higher cluster of cardiovascular risk factors compared with vegetarians, including increased body mass index, waist to hip ratio, blood pressure, plasma total cholesterol (TC), triacylglycerol and LDL-C levels, serum lipoprotein(a) concentration, plasma factor VII activity, ratios of TC/HDL-C, LDL-C/HDL-C and TAG/HDL-C, and serum ferritin levels. Compared with omnivores, vegetarians, especially vegans, have lower serum vitamin B₁₂ concentration and n-3 polyunsaturated fatty acid (PUFA) levels in the tissue membrane phospholipids, which are associated with increased collagen and ADP stimulated ex vivo whole blood platelet aggregation, plasma 11-dehydrothromboxane B₂, and homocysteine levels and decreased plasma HDL-C. This may be associated with an increased thrombotic and atherosclerotic risk. It is suggested that vegetarians, especially vegans, should increase their dietary n-3 PUFA and vitamin B₁₂ intakes.

Vegetarian diets and public health: biomarker and redox connections

Vegetarian diets are rich in antioxidant phytochemicals. However, they may not act as antioxidants in vivo, and yet still have important signaling and regulatory functions. Some may act as pro-oxidants, modulating cellular redox tone and oxidizing redox sensitive sites. In this review, evidence for health benefits of vegetarian diets is presented from different perspectives: epidemiological, biomarker, evolutionary, and public health, as well as antioxidant. From the perspective of molecular connections between diet and health, evidence of a role for plasma ascorbic acid as a biomarker for future disease risk is presented. Basic concepts of redox-based cell signaling are presented, and effects of antioxidant phytochemicals on signaling, especially via redox tone, sulfur switches and the Antioxidant Response Element (ARE), are explored. Sufficient scientific evidence exists for public health policy to promote a plant-rich diet for health promotion. This does not need to wait for science to provide all the answers as to why and how. However, action and interplay of dietary antioxidants in the nonequilibrium systems that control redox balance, cell signaling, and cell function provide rich ground for research to advance understanding of orthomolecular nutrition and provide science-based evidence to advance public health in our aging population.

Diet as prophylaxis and treatment for venous thromboembolism?

BACKGROUND

Both prophylaxis and treatment of venous thromboembolism (VTE: deep venous thrombosis (DVT) and pulmonary emboli (PE)) with anticoagulants are associated with significant risks of major and fatal hemorrhage. Anticoagulation treatment of VTE has been the standard of care in the USA since before 1962 when the U.S. Food and Drug Administration began requiring randomized controlled clinical trials (RCTs) showing efficacy, so efficacy trials were never required for FDA approval. In clinical trials of 'high VTE risk' surgical patients before the 1980s, anticoagulant prophylaxis was clearly beneficial (fatal pulmonary emboli (FPE) without anticoagulants = 0.99%, FPE with anticoagulants = 0.31%). However, observational studies and RCTs of 'high VTE risk' surgical patients from the 1980s until 2010 show that FPE deaths without anticoagulants are about one-fourth the rate that occurs during prophylaxis with anticoagulants (FPE without anticoagulants = 0.023%, FPE while receiving anticoagulant prophylaxis = 0.10%). Additionally, an FPE rate of about 0.012% (35/28,400) in patients receiving prophylactic anticoagulants can be attributed to 'rebound hypercoagulation' in the two months after stopping anticoagulants. Alternatives to anticoagulant prophylaxis should be explored.

METHODS AND FINDINGS

The literature concerning dietary influences on VTE incidence was reviewed. Hypotheses concerning the etiology of VTE were critiqued in relationship to the rationale for dietary versus anticoagulant approaches to prophylaxis and treatment.Epidemiological evidence suggests that a diet with ample fruits and vegetables and little meat may substantially reduce the risk of VTE; vegetarian, vegan, or Mediterranean diets favorably affect serum markers of hemostasis and inflammation. The valve cusp hypoxia hypothesis of DVT/VTE etiology is consistent with the development of VTE being affected directly or indirectly by diet. However, it is less consistent with the rationale of using anticoagulants as VTE prophylaxis. For both prophylaxis and treatment of VTE, we propose RCTs comparing standard anticoagulation with low VTE risk diets, and we discuss the statistical considerations for an example of such a trial.

CONCLUSIONS

Because of (a) the risks of biochemical anticoagulation as anti-VTE prophylaxis or treatment, (b) the lack of placebo-controlled efficacy data supporting anticoagulant treatment of VTE, (c) dramatically reduced hospital-acquired FPE incidence in surgical patients without anticoagulant prophylaxis from 1980 - 2010 relative to the 1960s and 1970s, and (d) evidence that VTE incidence and outcomes may be influenced by diet, randomized controlled non-inferiority clinical trials are proposed to compare standard anticoagulant treatment with potentially low VTE risk diets. We call upon the U. S. National Institutes of Health and the U.K. National Institute for Health and Clinical Excellence to design and fund those trials.

Vegetarian diets are associated with healthy mood states: a cross-sectional study in seventh day adventist adults

Background

The physical health status of vegetarians has been extensively reported, but there is limited research regarding the mental health status of vegetarians, particularly with regard to mood. Vegetarian diets exclude fish, the major dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), critical regulators of brain cell structure and function. Omnivorous diets low in EPA and DHA are linked to impaired mood states in observational and experimental studies.

Methods

We examined associations between mood state and polyunsaturated fatty acid intake as a result of adherence to a vegetarian or omnivorous diet in a cross-sectional study of 138 healthy Seventh Day Adventist men and women residing in the Southwest. Participants completed a quantitative food frequency questionnaire, Depression Anxiety Stress Scale (DASS), and Profile of Mood States (POMS) questionnaires.

Results

Vegetarians (VEG:n = 60) reported significantly less negative emotion than omnivores (OMN:n = 78) as measured by both mean total DASS and POMS scores (8.32 ± 0.88 vs 17.51 ± 1.88, p = .000 and 0.10 ± 1.99 vs 15.33 ± 3.10, p = .007, respectively). VEG reported significantly lower mean intakes of EPA (p < .001), DHA (p < .001), as well as the omega-6 fatty acid, arachidonic acid (AA; p < .001), and reported higher mean intakes of shorter-chain α-linolenic acid (p < .001) and linoleic acid (p < .001) than OMN. Mean total DASS and POMS scores were positively related to mean intakes of EPA (p < 0.05), DHA (p < 0.05), and AA (p < 0.05), and inversely related to intakes of ALA (p < 0.05), and LA (p < 0.05), indicating that participants with low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood.

Conclusions

The vegetarian diet profile does not appear to adversely affect mood despite low intake of long-chain omega-3 fatty acids.

Docosahexaenoic acid decreases plasma homocysteine via regulating enzyme activity and mRNA expression involved in methionine metabolism

OBJECTIVE

The objective of this study was to investigate the regulatory effect of fish oil rich in omega-3 polyunsaturated fatty acids (PUFAs) on critical enzyme activity and mRNA expression involved in homocysteine (Hcy) metabolism.

METHODS

Thirty-six male Sprague-Dawley rats aged 3 wk, weighing 120 +/- 10 g, were randomly divided into three groups: the olive oil (OO) group, the tuna oil (TO) group, and the salmon oil (SO) group. The oil was orally administered every day using a stomach tube. Eight weeks later, plasma Hcy, phospholipids, omega-3 PUFAs, enzyme activity, and mRNA expression in tissues were determined.

RESULTS

Compared with the control group, phospholipids, total omega-3 PUFAs, and omega-3/omega-6 PUFAs in the liver and lung were significantly elevated in the TO and SO groups; 22:6omega-3 in the liver and lung was significantly increased in the TO group; and 20:5omega-3 in the two tissues was significantly elevated in the SO group. The level of plasma Hcy was significantly decreased with TO; methionine adenosyl transferase (MAT) activity was significantly increased and MAT mRNA expression was significantly upregulated with TO; cystathionine-gamma-lyase mRNA expression in TO was significantly upregulated; however, cystathionine beta-synthase and S-adenosylhomocysteine hydrolases were not significantly changed when compared with control.

CONCLUSION

TO rich in 22:6omega-3 decreases the concentration of Hcy despite increasing MAT activity and upregulating MAT mRNA expression through compensatory cystathionine-gamma-lyase mRNA expression, both of which are involved in Hcy metabolism.

Gender-specific fatty acid profiles in platelet phosphatidyl-choline and -ethanolamine

Previous studies suggested that women synthesise docosahexaenoic acid (DHA) more efficiently from their precursors than men. This study investigated the relationship between diet, platelet phospholipids fatty acids and gender. Dietary intake and platelet phosphatidyl-choline (PC) and phosphatidylethanolamine (PE) fatty acids were determined in Caucasian 40 men and 34 women. Absolute and %energy intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), and DHA, and the ratios of total n-6/n-3 PUFA and linoleic/alpha-linolenic acids did not differ between the sexes. However, women had higher DHA in PC (1.19 vs 1.05 wt%, p<0.05) and PE (3.62 vs 3.21 wt%, p<0.05) than men. Also EPA (1.10 vs 0.93 wt%, p<0.05) was higher in women's PE. Conversely, men had elevated AA and total n-6 fatty acids in PC. The higher platelet DHA levels and lower platelet AA/EPA and AA/DHA ratios in women of child-bearing age compared with men, may lead to less platelet aggregation and vaso-occlusion.

Effects of plant-based diets on plasma lipids

Dyslipidemia is a primary risk factor for cardiovascular disease, peripheral vascular disease, and stroke. Current guidelines recommend diet as first-line therapy for patients with elevated plasma cholesterol concentrations. However, what constitutes an optimal dietary regimen remains a matter of controversy. Large prospective trials have demonstrated that populations following plant-based diets, particularly vegetarian and vegan diets, are at lower risk for ischemic heart disease mortality. The investigators therefore reviewed the published scientific research to determine the effectiveness of plant-based diets in modifying plasma lipid concentrations. Twenty-seven randomized controlled and observational trials were included. Of the 4 types of plant-based diets considered, interventions testing a combination diet (a vegetarian or vegan diet combined with nuts, soy, and/or fiber) demonstrated the greatest effects (up to 35% plasma low-density lipoprotein cholesterol reduction), followed by vegan and ovolactovegetarian diets. Interventions allowing small amounts of lean meat demonstrated less dramatic reductions in total cholesterol and low-density lipoprotein levels. In conclusion, plant-based dietary interventions are effective in lowering plasma cholesterol concentrations.

Platelet phospholipid n-3 PUFA negatively associated with plasma homocysteine in middle-aged and geriatric hyperlipaemia patients

Studies showed that increased dietary intake of n-3 polyunsaturated fatty acids (PUFA) has a cardiovascular beneficial effect. Increased plasma phospholipid (PL) docosahexaenoic acid (22:6n-3) is associated with decreased plasma homocysteine (Hcy). The aim of this study was to investigate the relationship between platelet PL fatty acid and plasma Hcy in middle-aged and geriatric hyperlipaemia patients (50 males, 31 females) and 65 healthy subjects (43 males, 22 females) in Hangzhou, China. Plasma Hcy demonstrated significant positive correlation with adrenic acid (22:4n-6) (r = 0.188, P = 0.018) and negative correlation with 22:6n-3 (r = -0.277, P = 0.001) and the ratio of n-3/n-6 (r = -0.231, P = 0.003) in sex-, age- and BMI-controlled partial correlation analysis. The present results suggest that increased ratio of n-3/n-6 PUFA in platelet PL is associated with decreased thrombotic risks such as plasma Hcy in middle-aged and geriatric hyperlipaemia patients in Hangzhou.

Personal and professional correlates of US medical students' vegetarianism

OBJECTIVE

To determine prevalence and correlates of US medical students' self-identification as vegetarians.

DESIGN

Medical students were anonymously surveyed via questionnaire three times: at freshmen orientation, orientation to wards, and during senior year.

SUBJECTS

Medical students in the Class of 2003 (n=1,849) at 15 US medical schools (response rate 80%).

OUTCOME MEASURES

We examined self-reported vegetarianism, abstinence from meat items on a food frequency questionnaire, and associations between students' vegetarianism and their health-related outcomes.

STATISTICAL ANALYSES

Bivariate associations were tested with chi(2) tests.

RESULTS

During medical school, 7.2% of students self-identified as vegetarians; this percentage declined over time. Those who were vegetarians for health reasons (66% of vegetarians) ate more fruits and vegetables than those who were vegetarians for nonhealth reasons (P=0.02). Vegetarians were more likely (P<0.01) than nonvegetarians to eat more fruits and vegetables (P=0.002); be women (P=0.009); be Hindu, Buddhist, or Seventh Day Adventist (P< or =0.0004); be politically liberal (P=0.007); have a body mass index < or =25 (P=0.008); or, as freshmen, to perceive nutrition counseling as highly relevant to their intended practices (P=0.007). Vegetarian students were no more likely to counsel patients about nutrition than were nonvegetarians.

CONCLUSIONS

Prevalence of vegetarianism was higher among US medical students than among other US adults, although the prevalence declined during medical school. Medical students and physicians with healthful personal practices are more likely to encourage such behaviors in their patients, although the specific nutrition habit of vegetarianism among medical students was unassociated with their nutrition counseling practices.

Influence of habitual diet on antioxidant status: a study in a population of vegetarians and omnivores

BACKGROUND

Antioxidant status can be used as a biomarker to assess chronic disease risk and diet can modulate antioxidant defence.

OBJECTIVE

To examine effects of vegetarian diet and variations in the habitual intakes of foods and nutrients on blood antioxidants.

SUBJECTS AND SETTING

Thirty-one vegetarians (including six vegans) and 58 omnivores, non-smokers, in Northern Ireland.

DESIGN

A diet history method was used to assess habitual diet. Antioxidant vitamins, carotenoids, uric acid, zinc- and ferric-reducing ability of plasma (FRAP) were measured in fasting plasma and activities of glutathione peroxidase (GPX), superoxide dismutase (SOD) and glutathione S-transferase (GST) and level of reduced glutathione (GSH) were measured in erythrocytes.

RESULTS

Vegetarians had approximately 15% higher levels of plasma carotenoids compared with omnivores, including lutein (P< or =0.05), alpha-cryptoxanthin P< or =0.05), lycopene (NS), alpha-carotene (NS) and beta-carotene (NS). The levels/activities of all other antioxidants measured were similar between vegetarians and omnivores. Total intake of fruits, vegetables and fruit juices was positively associated with plasma levels of several carotenoids and vitamin C. Intake of vegetables was positively associated with plasma lutein, alpha-cryptoxanthin, alpha-carotene and beta-carotene, whereas intake of fruits was positively associated with plasma beta-cryptoxanthin. Intake of tea and wine was positively associated with FRAP value, whereas intake of herbal tea associated positively with plasma vitamin C. Intakes of meat and fish were positively associated with plasma uric acid and FRAP value.

CONCLUSIONS

The overall antioxidant status was similar between vegetarians and omnivores. Good correlations were found between intakes of carotenoids and their respective status in blood.

Fatty acid composition of habitual omnivore and vegetarian diets

High-fat diets are implicated in the onset of cardiovascular disease (CVD), cancer, and obesity. Large intakes of saturated and trans FA, together with low levels of PUFA, particularly long-chain (LC) omega-3 (n-3) PUFA, appear to have the greatest impact on the development of CVD. A high n-6:n-3 PUFA ratio is also considered a marker of elevated risk of CVD, though little accurate data on dietary intake is available. A new Australian food composition database that reports FA in foods to two decimal places was used to assess intakes of FA in four habitual dietary groups. Analysis using the database found correlations between the dietary intakes of LC n-3 PUFA and the plasma phospholipid LC n-3 PUFA concentrations of omnivore and vegetarian subjects. High meat-eaters (HME), who consumed large amounts of food generally, had significantly higher LC n-3 PUFA intakes (0.29 g/d) than moderate meat-eaters (MME) (0.14 g/d), whose intakes in turn were significantly higher than those of ovolacto-vegetarians or vegans (both 0.01 g/d). The saturated FA intake of MME subjects (typical of adult male Australians) was not different from ovolacto-vegetarian intakes, whereas n-6:n-3 intake ratios in vegetarians were significantly higher than in omnivores. Thus, accurate dietary and plasma FA analyses suggest that regular moderate consumption of meat and fish maintains a plasma FA profile possibly more conducive to good health.

Toward a core nutraceutical program for cancer management

As previously suggested, it may be feasible to impede tumorevoked angiogenesis with a nutraceutical program composed of glycine, fish oil, epigallocatechin-3-gallate, selenium, and silymarin, complemented by a low-fat vegan diet, exercise training, and, if feasible, a salicylate and the drug tetrathiomolybdate. It is now proposed that the scope of this program be expanded to address additional common needs of cancer patients: blocking the process of metastasis; boosting the cytotoxic capacity of innate immune defenses (natural killer [NK] cells); preventing cachexia, thromboembolism, and tumor-induced osteolysis; and maintaining optimal micronutrient status. Modified citrus pectin, a galectin-3 antagonist, has impressive antimetastatic potential. Mushroombeta-glucans and probiotic lactobacilli can amplify NK activity via stimulatory effects on macrophages. Selenium, beta-carotene, and glutamine can also increase the number and/or cytotoxic activity of NK cells. Cachectic loss of muscle mass can be opposed by fish oil, glutamine, and beta-hydroxy-beta-methylbutyrate. Fish oil, policosanol, and vitamin D may have potential for control of osteolysis. High-dose aspirin or salicylates, by preventing NF-B activation, can be expected to aid prevention of metastasis and cachexia while down-regulating osteolysis, but their impacts on innate immune defenses will not be entirely favorable. A nutritional insurance formula crafted for the special needs of cancer patients can be included in this regimen. To minimize patient inconvenience, this complex core nutraceutical program could be configured as an oil product, a powder, and a capsule product, with the nutritional insurance formula provided in tablets. It would be of interest to test this program in nude mouse xenograft models.

A significant inverse relationship between concentrations of plasma homocysteine and phospholipid docosahexaenoic acid in healthy male subjects

The aim of this study was to investigate the possibility of a relationship between plasma homocysteine (Hcy) and phospholipid FA (PUFA) in healthy Australian males. One hundred thirty six healthy male subjects aged 20-55 yr were recruited from the Melbourne metropolitan area. Each volunteer completed a semiquantitative food frequency questionnaire and gave a blood sample. Plasma Hcy concentrations were determined by an established HPLC method; the plasma phospholipid FA were determined by standard methods. Plasma Hcy concentration was significantly negatively correlated with plasma phospholipid concentration of the PUFA 20:5n-3 (r = -0.226, P = 0.009), 22:5n-3 (r= -0.182, P= 0.036), 22:6n-3 (r= -0.286, P= 0.001), total n-3 (r = -0.270, P = 0.002) and the ratio n-3/n-6 PUFA (r = -0.265, P = 0.002), and significantly positively correlated with 20:4n-6 (r= 0.180, P= 0.037). In the partial correlation analysis, after controlling for serum vitamin B12 and folate concentration, plasma Hcy was significantly negatively correlated with the plasma phospholipid concentration of 22:6n-3 (r = -0.205, P = 0.019), total n-3 (r = -0.182, P= 0.038) and the ratio n-3/n-6 PUFA (r= -0.174, P= 0.048). Evidence indicates that an increased concentration of n-3 PUFA in tissues has a beneficial effect on cardiovascular health. Our findings provide further evidence that increased consumption of dietary n-3 PUFA increases the concentration of n-3 PUFA in plasma phospholipid, which is associated with a protective effect on cardiovascular diseases and lower plasma Hcy levels. The mechanism that might explain the association between plasma 22:6n-3 and Hcy levels is not clear.

Effects of docosahexaenoic acid supplementation on blood lipids, estrogen metabolism, and in vivo oxidative stress in postmenopausal vegetarian women

BACKGROUND

Vegetarians are generally deficient in long-chain n-3 fatty acids. Long-chain n-3 fatty acids have a beneficial effect on plasma lipid levels, and some studies showed that they had breast cancer suppression effect. One of the biomarkers of breast cancer risk is the ratio of urinary 2-hydroxyestrone (2-OHE(1)) to 16alpha-hydroxyestrone (16alpha-OHE(1)).

OBJECTIVE

To investigate the effect of docosahexaenoic acid (DHA, 22:6n-3) supplementation on blood lipids, estrogen metabolism and oxidative stress in vegetarians.

DESIGN

Single-blind, randomized, placebo-controlled trial.

INTERVENTIONS

Twenty-seven postmenopausal vegetarian women were recruited. After a 2-week run-in period with 6 g placebo corn oil, the subjects were subsequently randomized to receive either 6 g corn oil (n=13) or 6 g DHA-rich algae oil (2.14 g of DHA/day) (n=14) for 6 weeks. Two subjects in corn oil group withdrew before completion.

MAIN OUTCOME MEASURES

Plasma lipids, urinary 2-OHE(1) and 16alpha-OHE(1), urinary F(2)-isoprostanes and plasma alpha-tocopherol.

RESULTS

Plasma LDL-DHA and EPA level increased significantly by DHA supplementation. DHA decreased plasma cholesterol (C) levels (P=0.04), but did not influence the levels of plasma TG, LDL-C and HDL-C, alpha-tocopherol, urinary F(2)-isoprostanes, 2-OHE(1), 16alpha-OHE(1) and ratio of 2-OHE(1) to 16alpha-OHE(1) as compared to corn oil.

CONCLUSION

DHA supplementation at a dose of 2.14 g/day for 42 days decreases plasma cholesterol but neither does it show beneficial effects on estrogen metabolism, nor does it induce deleterious effects on the observed in vivo antioxidant or oxidative stress marker in postmenopausal vegetarian women.

SPONSORSHIP

A grant (# DOH89-TD-1062) from Department of Health, Executive Yuan, Taiwan.