The California Walnut Commission provided nuts to those study participants following the Mediterranean guidelines.
"There are two reasons why walnuts were part of the nut group, and that's because walnuts are traditionally a part of the Mediterranean diet," said Registered Dietitian Carol Burke Sloan with the commission. "And secondly, there's been much research on the cardiovascular benefits of eating walnuts, and because they were looking at lowering the risk of heart disease, walnuts were a very important part of this diet."
Roughly 99 percent of all U.S. produced walnuts come from California.
