Walnut-Rich Diet Boosts Heart-Health in Diabetics
Lee Swanson Research Update
A new study from Yale finds that daily consumption of walnuts, rich in polyunsaturated fatty acids, may improve the health of blood vessels, thereby decreasing the risk of heart disease.
Supplementing the diet of middle-aged diabetics with 56 grams of walnuts led to significant improvements in the function of the blood vessel lining (endothelium), and there was also a trend toward improved cholesterol levels, according to findings published in Diabetes Care.
The study adds to a growing body of science supporting the health benefits, and the heart benefits in particular, of increased consumption of nuts. Previous studies have reported benefits for almonds, macadamia nuts and pistachios.
Indeed, a recent study funded by the California Walnut Commission found that the fatty acids present in walnuts and fish oil may work in different ways to reduce the risk of coronary heart disease.
According to findings published in the American Journal of Clinical Nutrition (89:1657S-1663S, 2009), a diet supplemented with walnuts led to reductions in cholesterol levels, while a fish diet led to reductions in blood levels of triglycerides.
For the new study, David Katz and his co-workers from the Yale University School of Medicine recruited 24 type 2 diabetics with an average age of 58 and randomly assigned them to an ad libitum diet with or without 56 grams of walnuts for eight weeks.
At the end of the intervention period, blood flow was measured using flow-mediated dilation (FMD) and found to have "significantly improved" by 2.3 percent in the walnut group, compared to 1.2 percent in the non-supplemented group.
Furthermore, blood sugar levels and total cholesterol levels were also decreased from baseline values. However, these values did not reach significance compared to the non-walnut-eating group.
"A walnut-enriched ad libitum diet improves endothelium-dependent vasodilation in type 2 diabetics, suggesting a potential reduction in overall cardiac risk," concluded the researchers.
Diabetes Care Published online ahead of print.