A recent study published in JAMA Internal Medicine showed that peanuts may protect against death, especially death from cardiovascular disease. Of the 200,000 people studied from around the world, those who frequently ate peanuts and nuts were considerably less likely to have died from any cause, especially heart disease, compared to people who didn’t include peanuts and nuts in their diets. Another recent study points to how and why peanuts may be offering such substantial cardioprotective benefit.
Peanuts Promote Vascular Function
When included as part of a high-fat meal, peanuts improved post-meal triglyceride levels and maintained endothelial function. Researchers randomly separated 15 overweight men into two groups: a control group that drank a high-fat shake with no peanuts included, and a variable group that drank a high-fat shake with 3 ounces of ground peanuts. Both shakes were matched for calories and macronutrients.
Researchers measured lipid, glucose, and insulin levels 5 times following each meal and also assessed flow-mediated dilation (FMD) to determine vascular function. They did this by cuffing the forearm to restrict blood flow, and then releasing and measuring dilation of the brachial artery.
The control group drinking the peanut-free shake experienced an average 1.2% decrease in FMD. The peanut drinkers, however, exhibited no decrease in vascular function, suggesting that when peanuts are part of a high-fat meal they help protect vascular function.
Vascular function is inextricably linked to cardiovascular health. Vascular dysfunction promotes atherosclerosis (hardening of the arteries) and the development of coronary plaques that pave the way for coronary artery disease. It’s been shown that when you eat a high-fat meal, vascular function is impaired until the fat from your meal clears your bloodstream. Suppressing this effect, as peanuts seem to do according to this most recent study, may help reduce your risk of cardiovascular disease.
Lead researcher Xiaoran Liu, a graduate student in the Department of Nutritional Sciences at Pennsylvania State University, explains: “Previous studies have shown that individuals who consume peanuts more than 2 times a week have a lower risk of coronary heart disease. This study indicates that the protective effect of peanut consumption could be due, in part, to its beneficial effect on artery health.”
Peanuts are actually a legume, and quite nutrient-dense. They are a wonderful source of vitamin E (8 grams for every 100 grams of peanuts) and provide 85% of the daily recommend value of niacin. They also boast a nutritional profile rich in protein, fiber, folate, and the minerals manganese, iron, zinc, calcium, selenium, magnesium, and potatssium.
Peanuts owe their heart healthy properties to their high monounsaturated fat content, particularly oleic acid, the celebrated fat found in olive oil. Monounsaturated fats have been proven to help raise HDL “good” cholesterol levels and lower LDL “bad” cholesterol levels. A randomized, double-blind study made up of 22 people showed that a diet high in monounsaturated fats (particularly from peanuts and peanut butter) lowered heart disease risk by 21% compared to the average Western diet.
Peanuts also contain polyphenolic antioxidants like resveratrol, which offers protective benefits against cancers, heart disease, stroke, degenerative nerve disease, Alzheimer’s disease, and viral/fungal infections. Peanuts are also high in p-coumaric acid, which has been linked to a decreased risk for stomach cancer because it helps to suppress the formation of cancer-causing nitrosamines in the stomach.