In particular, nuts and peanuts are getting attention for their heart benefits. A study published in JAMA Internal Medicine on March 2, 2015, found that among 72,000 Americans in the southern United States and 135,000 people in China, eating peanuts (a legume) and nuts (such as almonds and walnuts) was associated with a reduction of 17% to 21% in the risk of dying from any cause, especially heart disease. This study was not a randomized trial, and therefore it cannot prove that a regular diet of nuts has such positive health effects. However, two previous randomized trials did find that such a diet was heart-healthy. “Nuts and peanuts are rich in unsaturated fatty acids, known for reducing inflammation, improving blood vessel function, and lowering LDL cholesterol,” says Debbie Krivitsky, director of clinical nutrition at the Cardiovascular Disease Prevention Center at Harvard-affiliated Massachusetts General Hospital. The American Heart Association recommends eating four servings of unsalted, unoiled nuts per week. A serving size is a small handful (1.5 ounces) of whole nuts or 2 tablespoons of nut butter.