Time to go buy some walnuts. Researchers in Spain found adults who ate a half-a-cup of walnuts each day for two years had lower cholesterol levels and a reduced risk of heart disease. Specifically, those who ate walnuts had 8.5 percent lower cholesterol, including modest reductions in their LDL (or “bad”) cholesterol. It’s also thought eating nuts can improve the quality of LDL particles. The American Heart Association says walnuts are high in omega 3 fatty acids—the heart-healthy fat famously found in oily fish.