Is Peanut Oil Healthy? A Deep Dive Into Its Nutrition Profile

Shopping for healthy cooking oils can get a little…complicated. Not only are there a ton of oils to choose from, but conflicting information about fats can make it difficult to decide which oils you should add to your cart and which you should leave on the shelf.

The peanut plant (Arachis hypogaea L.) is native to South America1 but is now grown all over the world, including across the United States. These plants produce bright yellow flowers above ground but develop their fruit underground, which is why peanuts are also known as groundnuts. Peanuts have a mild, earthy taste and creamy texture, thanks to their high fat content.

Because peanuts are high in fat, they're used to produce cooking oil along with other fat-based products like soap and animal feed.

Peanut oil has a high smoke point—the temperature at which an oil begins to smoke—of around 445 degrees Fahrenheit 2(229.4 degrees Celsius2), which is why it's commonly used in high-heat cooking methods like frying and stir-frying. When an oil reaches its smoke point, the fats start to break down3 and form harmful compounds such as alcohols, aldehydes, and ketones, which affect the flavor of the oil. This is why oils with higher smoke points are preferred for high-heat cooking. 

Peanut oil is mostly composed of unsaturated fatty acids—including monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs)—which make up around 80% of peanut oil6. The other 20% comes from saturated fat.

The monounsaturated fat oleic acid7 is the main fat in peanut oil. It's also rich in linoleic acid, a type of omega-6 polyunsaturated fat.

In terms of nutrition and potential health benefits, there's a difference between refined and unrefined peanut oil. Although the chemical refining process produces oil with desirable qualities like a longer shelf life, lower allergy risk, and a more neutral taste and color, it also strips12 the oil of nutrients7 that contribute to its health benefits.

Studies show that oleic acid—the main fat found in peanut oil—has anti-inflammatory13 properties and may have a positive effect on body weight.

A recent review14 published in Advances in Nutrition found that diets enriched in oleic acid may protect against obesity by interacting with AMP-activated protein kinase (AMPK)—an enzyme that plays an important role in appetite regulation and energy intake.

One tablespoon of peanut oil provides 14% of your daily vitamin E needs5. Vitamin E is the collective term for a group of fat-soluble compounds that function as antioxidants in the body. Antioxidants16 help protect cells by inhibiting oxidation—a chemical reaction that generates harmful compounds that can damage lipids, proteins, and DNA.

More than 90% of U.S. adults fall short of the RDA for vitamin E. Having low blood levels of vitamin E could negatively impact cellular health and even increase the risk of heart disease.

Peanut oil is a good source of phytosterols17 (fatty compounds that have antioxidant and anti-inflammatory properties) such as beta-sitosterol, campesterol, and stigmasterol. 

Although the body needs both omega-6 fats and omega-3 fats, omega-6s20 tend to be dominant in most people's diets. Omega-3 fats, which are mostly concentrated in seafood, have powerful anti-inflammatory properties and are important for cognitive health and immune function. Omega-6 fats, which tend to be more pro-inflammatory, are found in vegetable oils like canola oil, soybean oil, and peanut oil. Peanut oil is high in the omega-6 fat linoleic acid.

Because most Western diets are very high in ultra-processed foods made with vegetable oils and low in whole foods like seafood, it creates an imbalance between omega-3s and omega-6s, which can stoke inflammation20 and increase disease risk.

Even though you don't have to completely avoid oils high in omega-6 fats, it's important to follow a balanced diet high in omega-3s.

If your diet is too high in refined oils, like refined peanut oil, it could increase your risk of certain health issues.

A 2020 study21 published in the Journal of Nutrition found that Chinese adults with high intakes of cooking oils like peanut oil and refined blended plant oils were at a higher risk for developing Type 2 diabetes compared to those who didn't consume those oils. 

The researchers suggested that because these oils were almost exclusively used for high-heat cooking methods like deep-frying and stir-frying, heat-associated changes to the oil like the formation of trans fats and lipid peroxidation could contribute to inflammation, which plays a role in diabetes.

When oils that contain polyunsaturated fats, like peanut oil, are heated to high temperatures, it generates toxic compounds called lipid oxidation products (LOPs)22, which damage cells and increase the risk of heart disease, certain cancers, and neurological diseases.

Like with soybean oil, there is concern about aflatoxins with peanut oil. Found on agricultural crops that have been stored in hot and humid regions, aflatoxins are a highly toxic metabolite23 produced by a certain type of fungi.

Aflatoxin exposure can lead to hepatotoxicity, teratogenicity, and immunotoxicity23, and has been associated with an increased risk of liver cancer.

There is some carryover of aflatoxins from the whole peanuts to the oil, with one study showing a 15-35% carryover and another showing 1-12% in roasted peanuts.

Moral of the story: Peanut oil can be a part of a healthy diet, but it shouldn't be your main source of fat.

Fried foods, no matter if they're fried in peanut oil, lard, or another vegetable oil, should be limited in order to reduce disease risk and promote overall health.

Unrefined peanut oil provides a good source of vitamin E and phytosterols and can be used to make flavorful salad dressings, marinades, and sauces, but it's important to include other sources of fat in your diet as well.