LEVELS OF LIPID-PEROXIDATION IN SELECTED POPULATION GROUPS

The levels of conjugated dienes of fatty acids, which are the first pr oduct of lipid peroxidation, were estimated in vegetarians aged 18 to 39 years and compared to corresponding values of a non-vegetarian grou p of the same age. A similar comparison was performed between groups o f probands from Dolny Kubin, an area with low incidence of colorectal tumors, and Bratislava, where the incidence of this disease is very hi gh. Nutritional conditions in terms of lipid intake were evaluated by dietetic questionnaires and by estimation of plasma cholesterol levels . The values of lipid peroxidation were correlated with vitamin C cont ent which participates as an antioxidant in the neutralization of free oxygen radicals. Increased amounts of conjugated dienes were found in the plasma of vegetarians. Both the dietetic survey and low cholester ol levels (significant as compared to non-vegetarians) indicated a pre dominant intake of vegetable fats (and thus of unsaturated fatty acids ). In addition, low levels of vitamin C in leucocytes were found in th is group. Vitamin C content in non-vegetarians was above the lower lim it of physiological range. This can explain the reduced levels of conj ugated dienes as well. The levels of lipid peroxidation in the group f rom Dolny Kubin were significantly lower than those from Bratislava. H igher lipid peroxidation in the group from Bratislava did not correlat e with physiological levels of vitamin C in this group. Values in the group from Dolny Kubin were significantly lower, particularly in males they were well below 39.7 mumol.1(-1). Polluted environment in a larg e industrialized city like Bratislava probably significantly contribut es to this effect. One of the conclusions of this report is the necess ity to study the mechanisms of detoxification of reactive oxygen speci es.