Long-term effect of a trace amount of tea catechins with perilla oil on the plasma lipids in mice.

Cholesterol-free diets, which contain 0.003% tea catechins with perilla oil rich in alpha-linolenic acid, were given to male mice for periods of 6 and 15 months. Cholesterol levels decreased significantly in mice fed the catechin diet for 6 and 15 months compared to the animals fed the control diet. The phospholipid level of mice fed the catechin diet for 15 months was lower than that of animals fed the control diet. No marked difference in triglyceride levels between the catechin and control diet groups was observed. Hardly any enhancing effects of catechins on the percentages of n-3 polyunsaturated fatty acids in plasma lipids were found, although the eicosapentaenoic acid level at 15 months was reduced in the catechin diet group.