Background: Diets containing nuts reduce cardiovascular disease (CVD) risk factors. This has primarily been attributed to their fatty acid composition, but other constituents may also contribute. Peanuts, the most widely consumed "nut" (actually a legume), are a rich source of monounsaturated fatty acids (MUFA), magnesium and folate, but their effects on CVD risk factors are poorly characterized.
Objective: This study determined the effects of chronic peanut consumption on diet composition as well as serum lipids, magnesium and homocysteine concentrations in free-living subjects under different conditions of peanut intake.
Design: Fifteen normolipidemic adults participated in a 30-week cross-over intervention. Subjects were provided 500 (+136) kcal as peanuts during an eight-week free feeding (FF) diet. The same amount of peanuts was added during a three-week addition (ADD) diet or replaced an equal amount of other fats in the diet during an eight-week substitution (SUB) diet.
Results: Energy intake from fat was increased through greater intake of MUFA and polyunsaturated fatty acids, while saturated fatty acid intake remained relatively stable under all conditions. Triacylglycerol (TAG) was reduced by 24% during ADD (p < 0.05), by 17% during SUB (p < 0.05) and by 14% during four-weeks of FF, but then rebounded to baseline by week 8. Dietary fiber, magnesium, folate, alpha tocopherol, copper and arginine increased during all treatments (p < 0.05). Serum magnesium increased in 13 of 15 subjects during FF (p < 0.05). No changes were found in total plasma homocysteine concentration.
Conclusions: Regular peanut consumption lowers serum TAG, augments consumption of nutrients associated with reduced CVD risk and increases serum magnesium concentration.