Gender and dietary fat affect alpha-tocopherol status in F344/N rats

For four weeks, groups of eight male and eight female F344/N rats were fed diets containing 15.5, 20, 30 or 40% of energy (en%) as fat. The fat was composed of corn oil and beef tallow with 9 en% from linoleate in all diets. Females had greater mean hepatic alpha-tocopherol levels, whereas males had greater plasma alpha-tocopherol and cholesterol concentrations. In males, the plasma ratio of alpha-tocopherol/cholesterol was significantly greater than in females (P < 0.05). Plasma alpha-tocopherol increased with increasing en% fat (r = 0.51, P < 0.001) in both sexes, but dietary fat did not alter hepatic alpha-tocopherol levels. These results suggest that plasma alpha-tocopherol may serve as a biomarker of total dietary fat intake and that in F344/N rats gender differences affect alpha-tocopherol and cholesterol status.