A comparison of lymphocyte micronuclei and plasma micronutrients in vegetarians and non-vegetarians.

We performed a biochemical and cytogenetic epidemiological study to establish if there are significant differences between vegetarians (V) and non-vegetarians (NV) in their peripheral blood lymphocyte micronucleus (MN) index, which is a measure of chromosome damage rate. The levels of plasma vitamin C (VIT-C), vitamin E (VIT-E), vitamin B12 (B12) and folic acid were also analysed to assess if differences in chromosome damage rates were associated with these potentially antimutagenic micronutrients. Volunteers were classified as either 'vegetarian' if they had abstained from eating any flesh foods for at least 3 years prior to the study or 'non-vegetarian' if they consumed meat or meat products at least 5 days/week for at least 3 years before participation in the study. The volunteers in the study consisted of 47 male and 79 female V and 66 male and 72 female NV, all of whom were non-smokers for at least 3 years prior to the study. The age of the volunteers varied between 20 and 89 years. There was no significant difference in the slope of the age-related increase in MN index of V and NV of either sex. However, the MN index was significantly lower in NV males in the age group 20-40 years and significantly lower for V males in the 41-60 years age group. No difference between the MN index of older males was detectable and there also was no difference in the MN index of V and NV females across all age groups. V were generally found to have significantly higher plasma levels of VIT-C and folic acid, significantly lower levels of B12, and similar levels of VIT-E when compared with NV. VIT-C correlated positively with MN index in young males, but the reverse was true for B12. In young females folate and B12 appeared to correlate negatively with MN index. VIT-E had no apparent impact on MN index. These data suggest that the level of folate and B12 may be more important than VIT-C or VIT-E in minimizing chromosome damage rates in human lymphocytes. Overall, the data from this study do not support the hypothesis that V have a lower genetic damage rate than NV.