Peanuts have been recognized as a valuable protein source since the 1800s. Additionally, peanut butter became highly valued during World War II when meat was not readily available. A one-ounce serving of peanuts—about a handful—is considered a good source of protein based on the United States Department of Agriculture Nutrient Database, providing 7 grams of high quality, plant-based protein to your diet. Peanuts are classified as a both a legume botanically and a nut nutritionally, which means that it enjoys the best of both worlds. For example, peanuts contain more protein than any other nut, with levels comparable to or better than one serving of beans.
Since the protein in peanuts is plant-based, it carries with it additional components promoting positive health benefits like fiber and unique bioactives, unlike animal protein. Peanuts are high in arginine, an amino acid, which is one of the building blocks of protein. This amino acid is a precursor to nitric oxide, a compound that expands your blood vessels. It may help decrease blood pressure and reduce heart disease risk.
In fact, one early study, called the Optimal Macronutrient Intake Trial for Heart Health (OMNIHeart), compared three diets to determine effects on blood pressure as well as the optimal diet pattern for reducing the risk of cardiovascular disease. The first diet was based on the Dietary Approaches to Stop Hypertension (DASH) diet, which emphasized carbohydrates. The second diet had a higher fat level from healthy unsaturated fats. The third diet had higher protein levels, more than half of which were from plant sources, including peanuts and peanut butter.
The OMNIHeart study showed that, in addition to the benefits of substituting healthy fat for carbohydrates in the DASH diet, substituting healthy protein also further reduced blood pressure and the risk of heart disease.
Adding peanuts to your diet is a great way to add healthy protein. Plus, you’ll be consuming key nutrients and bioactives like arginine that can improve your blood pressure, decrease chronic disease risk, and promote longevity.
Healthy Fats: Monounsaturated and Polyunsaturated Fat
Peanuts, peanut butter, and peanut oil are full of healthy fats. More than 80% of the fats in peanuts are from heart-healthy unsaturated fats. At least half of that fat is monounsaturated fat, the kind found in olive oil and avocados. Further, more than 30% is polyunsaturated fat, another good fat key for the heart.
A “Key Recommendation” in the 2015-2020 Dietary Guidelines for Americans is to eat more plant-based proteins such as peanuts because they contain healthy monounsaturated and polyunsaturated fats and other important nutrients.
At Penn State University, a human study was conducted that providing people diets including peanuts and peanut butter or peanut oil as sources of high monounsaturated fat. The study compared this diet to 1) a low-fat diet higher in carbohydrates, 2) a diet high in olive oil, also high in monounsaturated fat, or 3) a traditional American diet high in saturated fat. Compared to the American diet, subjects following the high monounsaturated fat peanut diets lowered their total cholesterol levels by 11% and “bad” LDL cholesterol levels by 14%, while their “good” HDL cholesterol levels were maintained. The benefits of the peanut diets on cholesterol levels were comparable to the olive oil diet. In addition, the peanut diets reduced triglyceride levels, which were increased in the low-fat diet.
Data clearly shows that the amount and type of fat we eat can impact health in various ways. Choosing peanuts, peanut butter, and peanut oil will help you to consume more healthy fats—the type best for heart health.
Bad Fats: Saturated and Trans Fat
Simply stated, because peanuts are high in healthy fats, that means that they are low in so-called bad fats—the ones that may not be as favorable to our health. “Bad” fats include saturated fat and trans fat; saturated fat is found most often in animal products, while trans fat comes from the processing of adding hydrogens to unsaturated oils.
Peanuts, peanut butter, and peanut oil are all low in saturated fat. Peanuts and their oil naturally do not have any trans fat. Additionally, a 2001 U.S. Department of Agriculture study tested 11 commercial brands of peanut butter and found that in all brands, levels of trans fat were not detectable. Major health organizations such as the American Heart Association and the Institute of Medicine also recommend keeping intake of saturated and trans fats as low as possible.
Scientific studies show that when healthy fats replace bad fats in our diets, the risk of cardiovascular disease can be reduced. But that’s not all—this swap can also reduce the risk of developing chronic diseases as well as lower inflammation. Peanuts, peanut butter, and peanut oil are natural options that can help you keep with the guidelines and add healthy fats to your diet. Plus, since peanuts are a plant food, they are cholesterol-free!
Last reviewed: February 2019
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