It's time to set the record straight about whether peanuts are actually nuts—and find out why so many people are allergic to them
Are Peanuts Nuts? Two Experts Break It Down for Us
Updated on Apr. 30, 2025
Did you know that avocados and cucumbers are both technically fruits? It’s enough to make you question everything you thought you knew about food: Are eggplants fruit? Are watermelons berries? Are peanuts nuts?
That last question has sparked more debate than you’d expect. Because as it turns out, peanuts might not be nuts at all.
It may sound completely, well, nutty, but peanuts are a classic example of a misnomer. And they aren’t the only “nut” causing confusion: Pine nuts and walnuts are also head-scratchers. So if peanuts are not actually nuts, what are they?
We reached out to food experts Sarah Schlichter, RD, a registered dietitian and nutritional consultant, and Kristi Winkels, RDN, a registered dietitian nutritionist with a specialization in allergies, to set the record straight on this food fact. Read on to find out what they have to say about the burning question: Are peanuts nuts?
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Are peanuts nuts?
Technically, peanuts are not nuts. “Despite what many people think, if someone is defining peanuts by the way they are grown, they are actually legumes and not nuts,” says Schlichter.
More specifically, a peanut is a “legume of the pea family (Fabaceae), grown for its edible seeds,” according to Britannica. That’s right: Those “nuts” in the hard shell are actually seeds.
As Winkels points out, what sets peanuts apart from nuts is the fact that they grow underground. Technically, she says, nuts grow on trees.
However, the Peanut Institute notes that, for culinary and research purposes, many people do consider them nuts.
Are peanuts tree nuts?
How peanuts grow can be used as a way to classify them. Since peanuts grow below the ground, this means that they aren’t tree nuts. Remember, they’re not even nuts at all!
“Tree nuts grow above the ground on trees,” Schlichter says. Nuts that are technically tree nuts include pecans, hazelnuts, almonds, Brazil nuts, walnuts and pistachios.
What’s interesting about peanuts is that even though they are technically legumes, Winkels says that their composition is more similar to tree nuts, like the ones named above. This becomes evident when looking at the nutritional breakdown. One thing that peanuts, other legumes and tree nuts all have in common is that they’re all good sources of plant-based protein.
What is a legume, exactly?
OK, so you know what tree nuts are now. What about legumes? “Legumes are edible seeds that are enclosed in pods,” Schlichter says, adding that beans and peas are two other examples. Besides being a good source of plant-based protein, legumes are especially good for heart health, linked to a lower risk of heart disease, stroke and type 2 diabetes.
Both experts say that peanuts can definitely provide these health benefits. One study published in 2018 in the Journal of the American College of Cardiology found that people who ate peanuts regularly had a lower risk of heart disease than people who didn’t eat peanuts.
What other nuts aren’t really nuts?
The answer to the question “Are peanuts nuts?” can come as a surprise. It makes you wonder what other foods are mislabeled as nuts (and what you might get wrong on this food quiz). Winkels says that cashews are also often incorrectly classified as nuts. “They’re technically a drupe,” she says.
Um, come again? A drupe is a fruit with a hard, stony layer covering the seed. Fruits like cherries and peaches are drupes, but Schlichter says that some tree nuts—namely almonds, pistachios and coconuts—also fall under this classification. “Nuts contain both the fruit and the seed of the plant,” she adds.
Why does this terminology matter?
Deciding if peanuts are legumes or nuts may seem like an arbitrary debate, but the scientific answer to the question “What are peanuts classified as?” is very serious in the world of food labeling and safety. According to the U.S. Department of Agriculture (USDA), peanuts and tree nuts are among the most common food allergies in the United States. “Tree nuts have to be identified on food labels in the U.S. for this reason,” Winkels says.
But peanuts aren’t tree nuts. So do foods with peanuts have to be called out on the label? The answer is yes. Any food containing peanuts must say so on the label.
If a food product was made in a facility where there could be cross-contamination with nuts or peanuts, Winkels says, many companies voluntarily include this on the label, but they are not required to do so.
Why are so many people allergic to peanuts?
There’s no single reason why so many people are allergic to peanuts, but experts have theories, including:
- Higher consumption: Winkels says that one theory has to do with high peanut consumption in the United States. “We eat a lot of peanuts and peanut butter here, which may be why we have higher reported incidences of peanut allergies than other countries,” she says.
- Processing methods: A 2023 report published in the journal Foods tells us that certain peanut-processing methods, such as dry-roasting, can increase the allergenicity of peanut proteins. And since roasting happens to be the most common method of peanut processing in the U.S., it gives us insight into why cases of peanut allergies are higher in the region.
- Early exposure: A 2022 study published in Nutrients found that early exposure to peanuts could lower the risk of developing an allergy. In other words, a delayed exposure to peanuts could trigger an allergy. “This is noteworthy because for so long, parents were told to not give their children peanuts until they were around age 6, but now it seems that it may be better to expose infants to them,” she explains, adding that it’s best to talk to your pediatrician about this first.
- Genetic factors: Some other theories on peanut allergies point to genetics and less-active immune systems as likely culprits.
If you’re allergic to peanuts, what else might you be allergic to?
Unfortunately, the most common way people learn they are allergic to peanuts is by having a bad reaction after eating them. This can include hives or swelling, itching or tingling, throat tightness, shortness of breath, digestive problems or anaphylaxis, which can be a medical emergency. “People can also see an allergist to get specific skin testing as well,” Schlichter says.
Another reason to see an allergist for testing? People with peanut allergies have a higher likelihood of being allergic to tree nuts. According to the American Academy of Allergy Asthma & Immunology, 30% of people with a peanut allergy are also allergic to tree nuts.
Are peanuts healthy to eat?
If you don’t have an allergy or sensitivity to them, both registered dietitians we spoke with fully endorse including peanuts in your diet. “Peanuts are a good source of protein and unsaturated fats,” Winkels says, naming two nutrients that are particularly helpful in keeping blood sugar levels steady.
“Peanuts also offer an array of micronutrients, such as niacin, folate, pantothenic acid, vitamin E, copper, magnesium and manganese,” Schlichter says. “If someone is not allergic, there is no reason to avoid peanuts, as they are very nutrient-dense and easy to add into most dietary patterns.”
Nutritients in peanuts
Here’s a breakdown of some of peanuts’ primary nutrients (in amounts per 100 grams), according to the USDA:
- Calories: 567
- Protein: 25.8 g
- Total fat: 49.2 g
- Carbohydrates: 16.1 g
- Fiber: 8.5 g
- Total sugars: 4.72 g
- Calcium: 92 mg
- Iron: 4.58 mg
- Magnesium: 168 mg
- Phosphorus: 376 mg
- Potassium: 705 mg
- Sodium: 18 mg
- Zinc: 3.27 mg
- Copper: 1.14 mg
- Manganese: 1.93 mg
- Thiamin: 0.64 mg
Despite their confusing name (although counterpoint: “pealegumes” doesn’t exactly roll off the tongue), there’s nothing confusing about the health benefits of including peanuts in your diet. As long as you don’t have an allergy, they’re a great plant protein to have on hand. Dietitian approved!
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Sources:
- Sarah Schlichter, registered dietitian and nutrition consultant
- Britannica: “Peanut”
- The Peanut Institute: “Hisory & Facts”
- Kristi Winkels, registered dietitian who specializes in food allergies
- Advances in Nutrition: “Legume Consumption and Cardiometabolic Health”
- Journal of the American College of Cardiology: “Nut Consumption and Risk of Cardiovascular Disease”
- USDA: “Food Allergies: The ‘Big 9’”
- Foods: “Peanut Allergenicity: An Insight into Its Mitigation Using Thermomechanical Processing”
- Journal of the Science of Food and Agriculture: “Different thermal processing effects on peanut allergenicity”
- Nutrients: “Early Introduction of Allergenic Foods and the Prevention of Food Allergy”
- American Academy of Allergy Asthma & Immunology: “Everything You Need to Know about Tree Nut Allergy”
- USDA: “Peanuts, all types, raw”
