Nuts are an important source of healthy fats and protein in traditional diets. After analyzing 20 prospective cohort studies, researchers found that those eating the most nuts (peanuts and tree nuts total) had a 24%, 11%, 19%, 18%, and 19% lower risk of coronary heart disease, stroke, cardiovascular disease, total cancer, and all-cause mortality, respectively. The scientists estimate that even eating just one 15-20g serving of nuts each day (about 2-3 tablespoons) is associated with a protective effect.
BMC Medicine. 2016 Dec;14(1):207. (D Aune et al.)