Walnuts Reduce LDL Cholesterol

CAMBRIDGE, Mass.—Harvard researchers found high-walnut-enriched diets significantly decreased total and low-density lipoprotein (LDL) cholesterol during short-term trials (Am J Clin Nutr. 2009;90(1):56-63). Literature databases were searched for published trials that compared a specifically walnut-enhanced diet with a control diet. Researchers conducted a random-effects meta-analysis of weighted mean differences (WMDs) of lipid outcomes. Thirteen studies representing 365 participants were included in the analysis. Diets lasted four to 24 weeks with walnuts providing 10 to 24 percent of total calories.

When compared with control diets, diets supplemented with walnuts resulted in a significantly greater decrease in total cholesterol and in LDL-cholesterol concentrations. High-density lipoprotein (HDL) cholesterol and triglycerides were not significantly affected by walnut diets more than with control diets. Other results reported in the trials indicated walnuts provided significant benefits for certain antioxidant capacity and inflammatory markers and had no adverse effects on body weight.