Warning: This oil comes with potentially damaging side effects due to either the ingredient it's made from or the manufacturing process used to extract it. Because these negative effects overshadow the potential benefits, I do not recommend this oil for therapeutic use. Always be aware of the potential side effects of any herbal oil before using.
Many people have been awakened to the hidden health dangers lurking in vegetable oils like canola, soy and corn, and have now switched to healthful alternative oils like olive, avocado and coconut. Nut oils are also becoming popular, as are grapeseed, sesame and peanut oil — with peanut oil being a favorite when it comes to cooking. But is peanut oil ideal for your cooking needs? Keep reading and find out.
What is peanut oil?
Of the many kinds of oils1 peanut is a mildly sweet edible oil. Also called groundnut or arachis oil,2 it's made from Arachis hypogea, a low-growing, annual plant that is a member of the Fabaceae (Leguminosae) family. Despite the word "nut" in its name, peanut is actually a legume and grows underground,3 as opposed to other nuts like walnuts and pecans, which grow on trees (hence are called tree nuts).
Peanuts originated in South America,4 and they have a long place in history. According to the National Peanut Board, peanuts were used as sacrificial offerings by the Incans of Peru, who placed them alongside their mummies to help them cross over into the next life.
Ancient tribes in Central Brazil made a beverage from ground peanuts and maize. This is also where Europeans first came across this plant, and then brought it back to Spain. From there, the humble peanut spread to Asia and Africa, and then eventually to North America.5 As of 2018 the top four producers of peanuts worldwide are China, India, Nigeria and the United States.6
Types of peanut oil
Peanut kernels are eaten boiled or roasted, or crushed or chopped for use in cooking and confectionery. They also can be transformed into other products like peanut butter, peanut flour and peanut oil. According to The Peanut Institute, there are several types of peanut oil sold today:7
• Refined peanut oil — This is a processed product that's largely used in the fast food industry. The refining procedure includes bleaching and deodorizing. Since the process also removes the peanut proteins, this oil is nonallergenic and safe for people with peanut allergies.
According to The Peanut Institute, the refining process also produces an oil that prevents it from absorbing the flavors of the foods cooked in it, making it a favorite for restaurants that need to cook multiple items in the same batch of oil without the foods picking up each other's flavors.
• Gourmet roasted peanut oil — This oil is not refined and is valued because it retains many of the peanut's nutrients such as pytoesterols and vitamin E. Because it maintains its aromatic flavor, The Spruce Eats8 mentions that this type of peanut oil is often used for flavoring, rather than cooking, sometimes added into dressings, sauces and marinades or drizzled over a salad.
The Spruce Eats also mentions two other peanut oil products that some chefs might choose for certain recipes:
- Virgin or cold-pressed peanut oil — Since it's not refined, most of its natural flavors and aromas are still present. It has a light flavor that will not overpower the flavors of other ingredients.
- Peanut oil blends — These are varieties that have been blended with cheaper oils like soybean oil. As a result, you can buy them at a lower price. The oil it's blended with usually has a high smoking point as well.
For the best nutrients and unadulterated product, always look for packaging that says "100% peanut oil" on it. That way you don't have to worry about whether you're getting soybeans in your oil, which may be tainted with pesticide or herbicide residues.
Uses of peanut oil
Peanut oil is currently one of the most popular oils used in the kitchen, as it can be used for frying, sautéing or simply adding a mild nutty flavor to dishes. Asian cultures, particularly China, Laos, Vietnam and Cambodia, are fond of using peanut oil in their food preparation.9
Before you liberally use this oil for cooking, though, please remember that it has a high percentage of omega-6 fats, which can upset your omega 3 to 6 ratio, which can increase your risk of obesity, diabetes and heart disease.10 I advise you to limit your use of peanut oil for cooking or frying, and preferably use it without heating.
So what oil is best for cooking, then? Coconut oil is a much healthier choice. Not only it is stable enough to resist heat-induced damage, but it also contains high amounts of saturated fats, which are essential to your health. Peanut oil can also be used for aromatherapy; Stylecraze gives a few other ideas on how to use it:11
- Moisturize your skin by applying the oil to your face and washing it off after 20 minutes.
- Apply to your hair to help boost growth, moisturize split ends and regenerate damaged hair.
- Rub it on your scalp to help address dandruff and ease psoriasis.
Composition of peanut oil
The stability and shelf life of peanut oil are mainly brought on by its fatty acid composition.12 It is composed of 10.7% saturated fats, 71% monounsaturated fats and 20.9% polyunsaturated fats. The main fatty acids are oleic, palmitic and linoleic acids.13
Peanut oil has an extensive shelf life, provided it is stored properly. Unopened peanut oil can stay fresh for up to two years, but if opened, it only stays fresh for six months to one year. Store it in a cool, dry place, such as your pantry, away from sunlight. Make sure the bottle is closed tightly.14
Benefits of peanut oil
Peanut oil may have benefits against diabetes, as suggested by a 2006 animal study. The researchers studied the effect of groundnut oil on lipid profile, blood glucose, lipid peroxidation and antioxidant status among diabetic rats. They found that it "slightly but significantly decreases the blood glucose, HbA1c, lipid peroxidation and lipid profile, and increases antioxidant levels in diabetic rats."15
Another study found that peanut oil, as well as other peanut products like peanut butter, contain phytosterols (PS), which help reduce the risk of cancer.16
Despite its wealth of uses and potential benefits, peanut oil is not safe for everybody, mainly because of its allergens, which account for the majority of severe food-related allergic reactions.17 They're also contaminated with a potentially dangerous toxin — more on this below.
Is peanut oil safe?
Having a peanut allergy is no laughing matter, as it's one of the most severe food allergies known, and can lead to fatal side effects. If you have (or suspect you have) a peanut allergy, I advise you to avoid consuming peanut oil, even in very small amounts — don't even apply it topically.
Also, keep in mind that peanut oil is added to certain foods, so always read the label when grocery shopping. If you're dining out, ask your server to check if your food contains or is cooked with peanut, arachis or groundnut oil.
I also advise pregnant women and nursing moms to use peanut oil with caution. Consult your health care provider to find out if it's safe for you and your infant. If you have sensitive skin, do a skin patch test before using this oil topically.
Another reason why you should be cautious of peanut oil is that this plant is often heavily sprayed with pesticides and contaminated with a mycotoxin called aflatoxin.18 This is a toxic metabolite that comes from certain molds and fungi like Aspergillus flavus and Aspergillus parasiticus.19 They thrive in soil and in moist environments.
Peanuts can become contaminated during preharvest, storage or processing. Aflatoxin may cause side effects such as leaky gut and may even increase your risk of liver cancer.20
Potentially dangerous side effects of peanut oil
Anaphylaxis is a dangerous and sometimes deadly side effect of peanuts and peanut oil. If you have a peanut allergy and have unknowingly ingested or used peanut oil, you may experience severe side effects, such as difficulty breathing, swollen lips and throat, fainting, dizziness and chest congestion. Seek emergency health care immediately, as this can be fatal.21