Serum lipid profiles in Japanese women and men during consumption of walnuts

Objective: To determine the serum cholesterol, apolipoproteins and LDL oxidizability in young Japanese women and men during walnut consumption and to evaluate its active principle. Design: Experimental study with a randomized design. Subjects: Twenty healthy women and 20 healthy men. Interventions: Subjects were randomly assigned to consume each of two mixed natural diets for 4 weeks in a cross-over design. Reference and walnut diets were designed and the walnut diet had 12.5% of the energy derived from walnuts (44-58 g/day). Results: The total cholesterol and serum apolipoprotein B concentrations, and the ratio of LDL cholesterol to HDL cholesterol was significantly lowered in women and men when fed on the walnut diet, than when on the reference diet (P [less than or equal to] 0.05). The LDL cholesterol concentration was significantly lowered in women on the walnut diet (0.22 mmol/l, P=0.0008), whereas this decrease was not significant in men (0.18 mmol/l, P=0.078). The most prominent change in the fatty acid composition of the cholesteryl esters from serum after the walnut diet was an elevation of x-linolenic acid in women (76%, P Conclusions: [alpha]-Linolenic acid in the walnut diet appears to be responsible for the lowering of LDL cholesterol in women. Sponsorship: Kyushu University (Fukuoka, Japan) and the California Walnut Commission (California, USA). doi:10.1038/sj.ejcn.1601400 Keywords: cholesterol; Japanese diet; [alpha]-linolenic acid; oxidized LDL; walnuts
Introduction In a controlled, randomized, cross-over, clinical study, Sabate et al (1993) showed greater cholesterol-lowering effects of the National Cholesterol Education Program Step I diet (30% fat energy) in healthy [...]