Dietary polyunsaturates and serum alpha-tocopherol in adults
Christiansen, M.M.; Wilcox, E.B.
Journal of the American Dietetic Association 63(2): 138-142
1973
ISSN/ISBN: 0002-8223 PMID: 4718425 Document Number: 62056
The effect of diets with and without an increased amount of polyunsaturated fatty acids (PUFA) on serum alpha -tocopherol content and on susceptibility of erythrocytes to peroxide haemolysis was measured in normal subjects, 10 men and 10 women. For 24 weeks, half of the subjects ate a self-selected modified diet which had a polyunsaturated:saturated fatty acid ratio of 1.0 or greater, compared with 0.45 for controls. Dietary tocopherol:fatty acid ratios (E:PUFA) were calculated. Tocopherol values in the same individual showed wide variation from week to week but mean tocopherol values were within normal limits and were about the same for men and women. Serum tocopherol values did not appear to be directly influenced by the E:PUFA ratio, but were related to dietary tocopherol. The high polyunsaturated fat diet did not cause a decrease in serum tocopherol under the conditions of the study. The mean tocopherol values of persons on the modified diet increased while that of control subjects remained the same but the increase was not statistically significant. Other measures of vitamin E status, creatine:creatinine ratio and erythrocyte haemolysis, showed no evidence of tocopherol deficiency in tissues. An increased susceptiblity of red blood cells to haemolysis by hydrogen peroxide was not found in the experimental group. When haemolysis percentage was plotted against serum tocopherol concentration or on a scatter diagram to show changes in the values of these two variables, no linear relation was observed. The modified fat-controlled diet did not cause a related serum tocopherol deficiency, but did cause a slight increase in serum tocopherol. The use of increased amounts of highly unsaturated fats as readily available vegetable oils contributed substantial amounts of tocopherol to the diets.