This research was the part of the comprehensive study of genetics, immune, and nutritional aspects of aging in vegetarian population.
Materials and Methods:
Our study population consists of the group of 105 younger women (52 nonvegetarians and 53 vegetarians) and group of elderly women (35 nonvegetarians and 34 vegetarians). Following immune assays were used: Proliferative activity of T- and B-lymphocytes stimulated with mitogens and antigens, phagocytic activity of leukocytes (flow cytometry). Basic hematological parameters were measured.
Statistical analysis showed significant differences in hematological parameters between vegetarian and nonvegetarian population. People eating vegetarian diet had significantly lower white blood cell count and red blood cell count in both, older (P < 0.01; P < 0.001) and younger (P < 0.01, P < 0.001) populations in comparison with nonvegetarian subjects. Hematological parameters were decreased, but in normal reference range. Reduced white blood cell counts were discovered in individual cell populations. Younger vegetarians had significantly lower count of neutrophils (P < 0.001), monocytes (P < 0.05), and eosinophils (P < 0.01) compared with younger nonvegetarians. In older vegetarians, significantly lower lymphocyte (P < 0.001) and basophile (P < 0.01) counts were found.
Immune function analysis displayed significantly lower phagocytosis of monocytes and granulocytes in an older vegetarian population (vs. older nonvegetarians (P < 0.05, P < 0.001). Similar effect of diet was observed as decreased phagocytic activity of granulocytes in younger vegetarians. Regardless of age, respiratory burst of phagocytic cells was also significantly decreased in women vegetarians versus nonvegetarians (P < 0.05, P < 0.001). Older vegetarians revealed significantly suppressed proliferative response of T-lymphocytes to mitogens (P < 0.001).
In conclusion, our data indicate that a vegetarian diet might have a possible impact on human immune response.