Effect on mortality and reinfarction of adding fruits and vegetables to a prudent diet in the Indian experiment of infarct survival (IEIS)

Effect of maturity and processing on total, insoluble and soluble dietary fiber contents of Indian green leafy vegetables

Vegetables are very important in the diet and provide minerals, vitamins, antioxidants and fiber. A beneficial role of dietary fiber in human nutrition is known but the data on the effect of maturity and processing of Indian vegetables on dietary fiber and its fractions are not available. Hence, the present study was undertaken to generate data on total (TDF), insoluble (IDF) and soluble (SDF) dietary fiber contents of green leafy vegetables (GLV) and to assess the effect of leaf maturity and cooking on these parameters. Sixteen GLV (namely, agathi, alternanthera, amaranth, basella, cabbage, colocasia, coriander, curry leaves, drumstick, fenugreek, hibiscus, mint, portulaca, rumex, spinach and tender tamarind leaves) were analysed for TDF, IDF and SDF by the enzymatic and gravimetric method of the Association of Official Analytical Chemists. Among the GLV analysed, the TDF and IDF contents were the lowest (2.5 g% and 1.6 g%) in basella and were the highest (16.3 g% and 13.4 g%) in curry leaves. The SDF content ranged from 0.7 g% in spinach to 2.9 g% in curry leaves. The SDF as a percentage of the TDF ranged from 11.3% in tender tamarind leaves to 36.0% in basella, but the majority of GLV had around 25% of the TDF as SDF. Significant (P < 0.01) variation was observed between inter-species and intra-species in TDF, IDF and SDF contents of all the GLV. As the leaf matured from tender to mature and to coarse stage, the TDF and IDF contents of amaranth, basella, hibiscus, rumex and spinach increased significantly (P < 0.05), The SDF content significantly (P < 0.05) increased from tender to mature stage in all five GLV, but there was no further increase from mature to coarse stage except in rumex, where a significant (P < 0.01) increase (25%) was observed. Processing/cooking of GLV had no significant effect on their TDF, IDF and SDF contents.

Frequency of fruit and vegetable consumption and coronary heart disease in France and Northern Ireland: the PRIME study

Fruit and vegetable consumption is associated with low CHD risk in the USA and Northern Europe. There is, in contrast, little information about these associations in other regions of Europe. The goal of the present study was to assess the relationship between frequency of fruit and vegetable intake and CHD risk in two European populations with contrasting cardiovascular incidence rates; France and Northern Ireland. The present prospective study was in men aged 50–59 years, free of CHD, who were recruited in France (n 5982) and Northern Ireland (n 2105). Fruit and vegetable intake was assessed by a food-frequency questionnaire. Incident cases of acute coronary events and angina were recorded over a 5-year follow-up. During follow-up there was a total of 249 ischaemic events. After adjustment on education level, smoking, physical activity, alcohol consumption, employment status, BMI, blood pressure, serum total and HDL-cholesterol, the relative risks (RR) of acute coronary events were 0·67 (95% CI 0·44, 1·03) and 0·64 (95% CI 0·41, 0·99) in the 2nd and 3rd tertiles of citrus fruit consumption, respectively (P for trend <0·03). Similar results were observed in France and Northern Ireland. In contrast, the RR of acute coronary events for ‘other fruit’ consumption were 0·70 (95% CI 0·31, 1·56) and 0·52 (95% CI 0·24, 1·14) respectively in Northern Ireland (trend P<0·05) and 1·29 (95% CI 0·69, 2·4) and 1·15 (95% CI 0·68, 1·94) in France (trend P=0·5; interaction P<0·04). There was no evidence for any association between vegetable intake and total CHD events. In conclusion, frequency of citrus fruit, but not other fruits, intake is associated with lower rates of acute coronary events in both France and Northern Ireland, suggesting that geographical or related factors might affect the relationship between fruit consumption and CHD risk.

Antioxidant vitamins reduce oxidative stress and ventricular remodeling in patients with acute myocardial infarction

We analyzed soluble vascular adhesion molecules (sVCAM-1), reactive oxygen metabolites (ROMs) level, total antioxidant status (TAS) and telediastolic left ventricular volume (TLVV) in patients with myocardial infarction undergoing reperfusion therapy and treated with antioxidant vitamins (AT) or placebo (P) before and for 1 month after reperfusion. After reperfusion, sVCAM-1 serum concentration, reactive oxygen metabolites level, and TLVV were significantly higher in patients treated with placebo than in those treated with antioxidant vitamins, while TAS was significantly higher in patients treated with antioxidant supplementation. We observed that 48 hours after reperfusion sVCAM-1 (P) vs sVCAM-1 (AT) was 2.03+/-0.5 vs 1.63+/-0.7 microg/ml with p < 0.01; ROMs (P) vs ROMs (AT) were 335.60+/-35.80 vs 307.50+/-47.10 U.CARR with p < 0.05; TAS (P) vs TAS (AT) was 526.47+/-44.24 vs 737.65+/-51.15 micromol/l with p < 0.01; 1 week after reperfusion TLVV (P) vs TLVV (AT) was 125.12+/-29.80 vs 119.40+/-29.40 ml with p < 0.05; 1 month after reperfusion TLVV (P) vs TLVV (AV) was 132.00+/-33.50 vs 123.40+/-21.60 ml with p < 0.05. In the first period after infarction, vitamin treatment improves the antioxidant system and reduces oxidative stress, inflammatory process and left ventricular remodeling.

The associations between blood lipids and the Food Guide Pyramid: findings from the Third National Health and Nutrition Examination Survey

BACKGROUND

Dietary recommendations are based on nutrients, foods, and food groups, but the relationship between the Food Guide Pyramid (FGP) food groups and serum lipids has not been studied.

METHODS

NHANES III data were obtained for US adults who met the following criteria: aged 20-59 years, reliable participant, and typical 24-h recall. We examined whether serum lipids (serum total cholesterol (STC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triacylglycerol) were related to FGP food group intake (dairy, fruit, grain, meat, and vegetable).

RESULTS

A sample of 9111 participants qualified for this analysis. Fruit intakes were inversely related to STC, HDL-C, and LDL-C (P = 0.012, P = 0.001, and P = 0.014, respectively) and directly related to triacylglycerol levels (P = 0.003). Grain intake was inversely associated with both STC and HDL-C (P = 0.020 and P = 0.000). Dairy and meat intakes were directly related to LDL-C (P = 0.026 and P = 0.020).

CONCLUSIONS

Food groups are related to serum lipids. Universal definitions for food groups are needed in research and nutrition education. Studying the relationships between food groups and serum lipids is important for future dietary recommendations related to serum lipids.

Role of dietary factors in ethnic differences in early risk of cardiovascular disease and type 2 diabetes

BACKGROUND

The disparity in the prevalence of cardiovascular disease and type 2 diabetes between African Americans and whites has been well established, and ethnic differences in several risk factors for these diseases are evident in childhood.

OBJECTIVE

The current study explored whether dietary factors explain ethnic differences in serum lipids and insulin profiles in children, independent of body composition and social class background.

DESIGN

The sample included 95 African American and white children (mean age: 10.0 y). Macronutrient and food group intakes were derived from three 24-h recalls. Cardiovascular disease and type 2 diabetes risk were determined on the basis of total cholesterol, triacylglycerol, insulin sensitivity (S(i)), and acute insulin response (AIR). Data were analyzed by using t tests, analysis of covariance, and multiple regression.

RESULTS

African American children had lower triacylglycerol (P < 0.01), lower S(i) (P < 0.001), and higher AIR (P < 0.001) than whites. Intake of fruit and vegetables was significantly higher, and dairy intake lower, in African American than in white children after adjustment for social class and total energy intake. Several direct relations were observed between diet and insulin action: carbohydrate and fruit intakes were positively associated with S(i) (P = 0.02), and vegetable intake was negatively associated with AIR (P = 0.01). However, neither macronutrient nor food group intake accounted for the ethnic differences in triacylglycerol and AIR.

CONCLUSIONS

The African American children in our sample showed a greater disease risk than did the white children, even after body composition, social class background, and dietary patterns were adjusted for.

Health effects of vegetables and fruit: assessing mechanisms of action in human experimental studies

Epidemiologic data support the association between high intake of vegetables and fruits and low risk of chronic disease. There are several biologically plausible reasons why consumption of vegetables and fruit might slow or prevent the onset of chronic diseases. Vegetables and fruit are rich sources of a variety of nutrients, including vitamins, trace minerals, and dietary fiber, and many other classes of biologically active compounds. These phytochemicals can have complementary and overlapping mechanisms of action, including modulation of detoxification enzymes, stimulation of the immune system, reduction of platelet aggregation, modulation of cholesterol synthesis and hormone metabolism, reduction of blood pressure, and antioxidant, antibacterial, and antiviral effects. Although these effects have been examined primarily in animal and cell-culture models, experimental dietary studies in humans have also shown the capacity of vegetables and fruit and their constituents to modulate some of these potential disease-preventive mechanisms. The human studies have relied on intermediate endpoints related to disease risk. Design methodologies used include multiple-arm trials, randomized crossover studies, and more compromised designs such as nonrandomized crossovers and pre- and posttreatment analyses. Length of treatment ranged from a single dose to years depending on the mechanism of interest. Stringency of dietary control varied from addition of supplements to a habitual diet to provision of all food for the duration of a treatment. Rigorously conducted experimental dietary studies in humans are an important link between population- and laboratory-based research.

Disease incidence and longevity are unaltered by dietary antioxidant supplementation initiated during middle age in C57BL/6 mice

The ability of augmented antioxidant consumption to alter disease incidence, lesion burden and/or longevity was studied in adult male C57BL/6 mice. Mice were fed modified AIN76 diet or modified AIN76 supplemented with vitamin E, glutathione (GSH), vitamin E and GSH, melatonin or strawberry extract starting at 18 months of age. All the mice in this study were heavier than reference populations of male C57BL/6 mice fed NIH-07 or NIH-31, which were maintained without a mid-life change in diet. Fatty liver, focal kidney atrophy and proteinacious casts in the renal tubules were observed more frequently in this study population than in the reference populations. Lesion burden and incidence of specific lesions observed amongst the various groups in this study did not differ. There were no differences observed for longevity of any of the study groups. The longevity observed in this study was similar to that previously reported for male C57BL/6 mice. Thus, diet supplementation with antioxidants initiated during middle age did not appear to affect age-associated lesions patterns, lesion burden or longevity for ad libitum fed male C57BL/6 mice.

Effect of a diet high in vegetables, fruit, and nuts on serum lipids

We assessed the effect of a diet high in leafy and green vegetables, fruit, and nuts on serum lipid risk factors for cardiovascular disease. Ten healthy volunteers (seven men and three women aged 33 +/- 4 years [mean +/- SEM]; body mass index, 23 +/- 1 kg/m2) consumed their habitual diet (control diet, 29% +/- 2% fat calories) and a diet consisting largely of leafy and other low-calorie vegetables, fruit, and nuts (vegetable diet, 25% +/- 3% fat calories) for two 2-week periods in a randomized crossover design. After 2 weeks on the vegetable diet, lipid risk factors for cardiovascular disease were significantly reduced by comparison with the control diet (low-density lipoprotein [LDL] cholesterol, 33% +/- 4%, P < .001; ratio of total to high-density lipoprotein [HDL] cholesterol, 21% +/- 4%, P < .001; apolipoprotein [apo] B:A-I, 23% +/- 2%, P < .001; and lipoprotein (a) [Lp(a)], 24% +/- 9%, P = .031). The reduction in apo B was related to increased intakes of soluble fiber (r = .84, P = .003) and vegetable protein (r = -.65, P = .041). On the vegetable compared with the control diet, the reduction in total serum cholesterol was 34% to 49% greater than would be predicted by differences in dietary fat and cholesterol. A diet consisting largely of low-calorie vegetables and fruit and nuts markedly reduced lipid risk factors for cardiovascular disease. Several aspects of such diets, which may have been consumed early in human evolution, have implications for cardiovascular disease prevention.