Seasonal folate serum concentrations at different nutrition.

Folic acid (vitamin B9) rich sources are leafy green vegetables, legumes, whole grains, egg yolk, liver, and citrus fruit. In winter and early spring, there could be insufficient supply of vegetables and fruit and thus lower intake of folic acid and possible deficient folic acid blood concentrations. The aim of the study was to assess serum vitamin B9 concentrations depending on the season (the last third of winter - March, the last third of spring - May/June and the beginning of autumn - September) and different nutritional habits (apparently healthy adults non-smoking, non-obese 366 subjects; 204 persons of general population on traditional mixed diet; and 162 long-term lacto-ovo vegetarians). In general population group, the mean concentration of folate in March was low (narrowly above lower reference limit) with high incidence of deficient values - 31.5%. In May/ June vs. March was folate concentration significantly higher with deficient values in 13.2% of individuals. The highest serum values were observed in September with 11.1% of deficient values. In vegetarian vs. non-vegetarian group, significantly higher folate concentrations were found in each season with no deficient values. Folate and vitamin B12 are the regulators of homocysteinemia; plant food lacks of vitamin B12. The deficient folate serum values in March caused the mild hyperhomocysteinemia in 12.3% of individuals vs. only 5.9% and 4.8% of subjects in groups investigated in May/June and September. In spite of high folate concentrations in all investigations and no deficient value, 19.6-22.8% of vegetarians suffer from mild hyperhomocysteinemia as a consequence of deficient vitamin B12 concentrations in one quarter of subjects. As far as the general population is concerned, our findings suggest that winter and early spring are critical seasons in regards to optimal serum folate concentrations.

The association between high plasma homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet.

BACKGROUND: A long-term vegetarian diet is generally poor in vitamin B group. The lack of vitamin B(12) together with vitamin B(6) and folate deficiency is closely related to homocysteine metabolism. Hyperhomocysteinemia was found to be associated with increased bone turnover markers and increased fracture risk. Thus, hyperhomocysteinemia, vitamin B(12) and folate deficiency may be regarded as novel risk factors for micronutrient deficiency-related osteoporosis. AIM OF THE STUDY: To assess the possible impact of a vegetarian diet on bone mineral density in cohort of Slovak vegetarian women. METHODS: Fasting serum glucose, albumin, calcium, phosphorous and creatinine as well as bone markers, serum vitamin B(12), folate and plasma levels of total homocysteine were assessed in two nutritional groups (vegetarians vs. nonvegetarians) of apparently healthy women (age range 20-70 years). Bone mineral density of the femoral neck, trochanter, total femur and lumbar spine was measured in all subjects. RESULTS: Vegetarians had a significantly lower weight (p < 0.05), higher PTH (p < 0.01) and homocysteine (p < 0.001). Vitamin B(12) was significantly higher in nonvegetarians (p < 0.001). No differences were observed in folate levels. Univariate analysis showed significant association between homocysteine and B(12) (p < 0.01), folate (p < 0.001), creatinine (p < 0.001), total proteins (p < 0.049), age (p < 0.001) and vegetarian food intake (p < 0.001). Vegetarians had a significantly lower TrFBMD (p < 0.05) and ToFBMD (p < 0.05). Age and CTx were significant predictors in all sites of measured BMD and PTH. A strong correlation between homocysteine and FNBMD (r = -0.2009, p < 0.002), TrFBMD (r = -0.1810, p < 0.004) and ToFBMD (r = -0.2225, p < 0.001) was found in all subjects. CONCLUSION: Homocysteine is one of the predictors of bone mineral density, and hyperhomocysteinemia is associated with lower bone mineral density. In healthy adults, homocysteine levels are dependent on age as well as on nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of osteoporosis development than nonvegetarian women.

The relationship between micronuclei in human lymphocytes and selected micronutrients in vegetarians and non-vegetarians.

A vegetarian diet results in higher intake of vitamins and micronutrients, which - although providing antioxidant defence - may lead to deficiency in other micronutrients involved in DNA metabolism and stability (such as vitamins belonging to the B group). The principal difference among various vegetarian diets is the extent to which animal products are avoided. We have performed a pilot study to determine the relationship between the micronucleus frequency in lymphocytes and diet, and we compared the levels of Vitamins C and E, beta-carotene, B(12), folic acid, homocysteine and total antioxidant capacity in healthy vegetarians and non-vegetarians. The vegetarian group, consisting of 24 volunteers (13 women and 11 men), were matched for age and sex with 24 volunteers (12 women and 12 men) with a traditional dietary habit. Among the vegetarians were 13 lacto-ovo-vegetarians with average duration of vegetarian diet 10.8 years (ranging from 5 to 26 years) and 11 lacto-vegetarians with average duration of vegetarian diet 8.2 years (ranging from 3 to 15 years). Homocysteine, Vitamins C and E and beta-carotene levels in plasma were assayed by HPLC, and serum folate and Vitamin B(12) were determined with Elecsys Immunoassay tests. The total antioxidant capacity of plasma was estimated by measuring the ferric-reducing activity in a spectrophotometric assay. Micronuclei were measured in cytokinesis-blocked lymphocytes. Vegetarians had significantly higher levels of Vitamin C and beta-carotene (but not Vitamin E) in plasma compared with non-vegetarians (P<0.001). There were no significant differences in serum levels of folic acid and Vitamin B(12) between the monitored groups. Levels of folic acid in vegetarians correlated with length of vegetarianism (r=0.62, P=0.001, N=24). Vegetarians had elevated levels of homocysteine compared with non-vegetarians (P=0.007), as did vegetarian women compared with non-vegetarian women (P=0.031). We did not find any differences in total antioxidant capacity or in micronucleus frequency between the groups. Micronuclei correlated with age (r=0.62, P<0.001, N=48), women having higher frequencies than men. Multifactorial regression analysis showed significant effects of age, sex and total antioxidant capacity on micronucleus frequency (N=48, P<0.001).

Association of metabolic syndrome risk factors with selected markers of oxidative status and microinflammation in healthy omnivores and vegetarians.

Conditions predisposing to metabolic syndrome (MetS) are associated with increased oxidative stress and inflammation. We studied, in vegetarians (n = 90) and omnivores (n = 46), the impact of the dietary regimen on the occurrence of MetS risk factors (RFs: BMI, blood pressure, glucose metabolism and lipid profile) in relation to oxidative status (advanced glycation end products (AGEs), advanced oxidation protein products (AOPPs), malondialdehyde, ferric reducing ability of plasma, vitamins A, E, C, beta-carotene and superoxide dismutase activity) and microinflammation (C-reactive protein, leukocytes and neopterin). The proportion of subjects without/positive for one or two MetS RFs was comparable between the groups. From the components of MetS only immunoreactive insulin levels differed significantly (95% CI: omnivores: 5.0-7.1 microU/mL, vegetarians: 4.5-5.4, p = 0.03). Omnivores had lower AOPP (omnivores: 0.29-0.36 micromol/g albumin, vegetarians: 0.36-0.52, p = 0.01) and beta-carotene levels than vegetarians, they consumed more calories, proteins, fat and saturated fatty acids, and less fibres, beta-carotene and vitamin C. Multiple regression analysis revealed vitamin E and AOPP levels as the most important independent determinants of MetS RFs. The vegetarian diet seems to exert beneficial effects on MetS RFs associated microinflammation. Whether the vegetarian diet may counteract the deleterious effects of elevated AOPPs and AGEs, remains to be elucidated.

No evidence of insulin resistance in normal weight vegetarians. A case control study.

BACKGROUND: Diets rich in carbohydrates with a low glycemic index and with high fiber content are associated with flat post-prandial rises of blood glucose, minimal post-prandial insulin secretion and maintenance of insulin sensitivity. Protective food commodities in the prevention of cardiovascular disease, insulin resistance syndrome or diabetes are crucial components of the vegetarian diet. AIM OF THE STUDY: Insulin resistance values were assessed in relation to different nutrition. Metabolic abnormality is a predictor of age-related diseases and can be more pronounced in obese subjects. Insulin resistance values in normal weight subjects of two different nutritional habits were correlated with age. METHODS: Fasting concentrations of glucose and insulin as well as calculated values of insulin resistance IR (HOMA) were assessed in two nutritional groups of apparently healthy adult subjects (age range 19 - 64 years) with normal weight (body mass index 18.6 - 25.0 kg/m(2)): a vegetarian group (95 long-term lacto-ovo-vegetarians; duration of vegetarianism 10.2 +/- 0.5 years) and a non-vegetarian control group (107 subjects of general population on traditional western diet). Intake of energy and main nutrients (fats, saccharides, proteins) was similar in both groups. RESULTS: Glucose and insulin concentrations and IR (HOMA) values were significantly lower in vegetarians (glucose 4.47 +/- 0.05 vs. 4.71 +/- 0.07 mmol/l; insulin 4.96 +/- 0.23 vs. 7.32 +/- 0.41 mU/l; IR (HOMA) 0.99 +/- 0.05 vs. 1.59 +/- 0.10). IR (HOMA) dependence on age was only significant in subjects on a western diet. A significant increase of IR was found already in the age range 31-40 years, compared to vegetarians and it continued in later age decades. Age independent and low insulin resistance values in vegetarians are a consequence of an effective diet prevention by long-term frequent consumption of protective food. Vegetarians had a significantly higher consumption of whole grain products, pulses, products from oat and barley. CONCLUSION: The results of age independent and low values of insulin resistance document a beneficial effect of long-term vegetarian nutrition in prevention of metabolic syndrome, diabetes and cardiovascular disease.

Does a vegetarian diet influence genomic stability?

BACKGROUND: The vegetarian lifestyle is supposedly healthy, and differences between vegetarians and non-vegetarians in biomarkers related to diseases such as cancer might be expected. AIM OF THE STUDY: To investigate the possible role of different diets in maintaining genomic stability. METHODS: The vegetarian group, consisting of 24 volunteers (13 women and 11 men), were matched for age and sex with 24 volunteers (12 women and 12 men) with a traditional dietary habit. Among vegetarians there were 13 lacto-ovo-vegetarians (8 women, 5 men) with average length of vegetarian diet 10.8 years (ranging from 5 to 26) and 11 lacto-vegetarians (5 women, 6 men) with average length of vegetarian diet 8.2 years (ranging from 3 to15). All volunteers were nonsmokers, non-consumers of alcohol and had similar education and patterns of physical activity. Chromosome aberrations, micronuclei and DNA damage (strand breaks, oxidised bases and H(2)O(2)-sensitivity) were examined in peripheral blood lymphocytes of vegetarians and non-vegetarians. Plasma antioxidant status was assessed with the FRAP assay. RESULTS: We did not find any differences in percentage of cells with chromosome aberrations or in the frequency of micronuclei between vegetarians and non-vegetarians or between lacto-ovo and lacto-vegetarians. There was no statistically significant difference in total antioxidant capacity between the groups. The group with traditional dietary habits had significantly higher levels of oxidative DNA damage (strand breaks and oxidised purines, P = 0.005) compared with vegetarians. A significant positive correlation between age and oxidative DNA damage (net FPG-sensitive sites) was found in non-vegetarians, while there was an opposite trend towards a negative association in vegetarians. On the other hand chromosome aberrations correlated with age in vegetarians (r = 0.48, P = 0.017) but not in non-vegetarians. CONCLUSIONS: Our results indicate that a vegetarian diet can lead to a slight decrease in oxidative DNA damage in lymphocytes, but other markers of genetic stability are not affected. The lowest level of DNA damage was found in lymphocytes of lactovegetarians, (especially oxidised pyrimidines, P = 0.0017), suggesting that this diet provides some protection against oxidative stress.