- What Is Peanut Oil?
- 5 Reasons to Avoid Peanut Oil
- Practical Tips For Choosing the Right Oils
- Bottom Line: Avoid Peanut Oil
What does peanut oil have in common with other polyunsaturated vegetable oils like soybean oil, safflower oil, and sunflower oil?
Aside from being popular cooking oils, they’re all touted by the American Heart Association (AHA) as heart-healthy options. Yet, current science doesn’t support any of these claims.
Is peanut oil healthy? Read on to get the details about peanut oil — backed by science — so you can make the right decision for your health.
What Is Peanut Oil?
Peanut oil has a perfectly nutty taste, great for umami-flavored dishes and fried foods. If you like that golden, crispy texture of fried food, then you’re very familiar with this oil.
Peanut oil comes from the peanut plant. The peanut is crushed and the oil is pressed from the legume. Then the oil is served unrefined or processed further to create a refined version of the oil.
In terms of fatty acid profile, peanut oil looks like this[*]:
- Saturated Fatty Acids (SFAs): 20%
- Monounsaturated Fatty Acids (MUFAs): 50%
- Polyunsaturated Fatty Acids (PUFAs): 30%
There are about 216 grams of total fat in a one-cup serving[*].
It’s not a significant source of vitamin C, vitamin A, or dietary fiber.
High in MUFAs and PUFAs and low in SFAs, peanut oil is the kind of fat the AHA recommends to reduce heart disease risk.
Unfortunately, recent science does not support this recommendation.
5 Reasons to Avoid Peanut Oil
Be aware of these five reasons to avoid peanut oil. You might be shocked at all the negative things it could do to your body.
#1: It Causes Oxidative Stress
But there are a couple of problems with this popular oil that negate its vitamin E content. First, the oil oxidizes when you heat it, which creates more free radicals.
Second, it’s rich in omega-6 fatty acids, which throws off your omega-3 to omega-6 fatty acid ratio.
You want your ratios to be about 1:1 omega-6s to omega-3s or 4:1 at the very least. The standard American diet provides most people with a ratio more like 20:1[*].
These two things — omega-6 content and high rates of oxidation — make peanut oil high in free radicals, which cause oxidative stress.
Oxidative stress — fueled by reactive oxygen species (ROS) — are linked to numerous chronic diseases[*].
If you’re looking for healthy fats rich in vitamin E, opt for palm oil or avocado oil.
#2: It Affects Cholesterol
There’s evidence that polyunsaturated fats like peanut oil can lower LDL cholesterol, often mislabeled “bad cholesterol”[*]. That’s one of the main reasons PUFAs are touted to be “heart-healthy.”
One clinical trial demonstrated that peanut oil could lower LDL cholesterol levels[*], which led researchers to claim that this oil is good for your heart. But there are problems with this conclusion, including:
- LDL cholesterol isn’t a good predictor of cardiovascular disease (CVD) risk. LDL particle number and triglyceride-to-HDL ratio are much better predictors of CVD)[*].
- Eating high omega-6 PUFA oils increases the omega-6 to omega-3 ratio, which is linked to obesity — a known CVD risk factor[*].
- Cooking with high-linoleic oils means eating oxidized lipids — also terrible for heart health[*].
#3: It Can Negatively Impact Your Heart
Are there health benefits for your heart when you consume peanut oil? No. The opposite is true.
Saturated and monounsaturated fats, thanks to the strength of their hydrogen bonds, tend to be heat stable. But not all fats hold up to heat.
For example, peanut oil contains the omega-6 PUFA linoleic acid. When you expose linoleic acid to high temperatures — like you fry it — those lipids oxidize.
You’ve smelled oxidized lipids before. Rancid food is oxidized. Old vegetable oils sitting in the back of your cupboard are oxidized.
These oxidized lipids are highly atherogenic. In other words, they cause heart disease[*].
How does this work? Once digested, oxidized lipids often glom onto lipoproteins — the particles that carry cholesterol throughout your blood.
And when low-density lipoprotein (LDL) carries oxidized lipids, that LDL particle is more likely to become oxidized too.
Oxidized LDL is more likely to penetrate your arterial wall and cause an inflammatory immune response. This is how atherosclerotic plaques develop.
But that’s not all. Once consumed, oxidized lipids also interact with free radicals in your bloodstream to create even more inflammation[*]. This inflammatory cascade contributes to heart disease and obesity.
#4: It’s Linked to Obesity
There are several paths to obesity — a high-carb diet being one of them[*]. But a major contributing factor to the obesity epidemic is a high-PUFA diet.
Polyunsaturated fats like linoleic acid raise your omega-6 to omega-3 ratio, which increases your risk of obesity[*].
Another omega-6 PUFA, arachidonic acid, can also cause obesity. And nothing raises arachidonic acid levels like consuming linoleic acid[*].
In one rodent study, two groups of mice were given one of two diets: high-linoleic and low-linoleic. After 14 weeks, the high-linoleic “modern American mice” became obese[*].
There’s clinical evidence too. For eight weeks, researchers added peanut oil to the daily smoothie of both lean and overweight people. By the end, both groups had gained weight[*].
Consuming high-linoleic oil from peanuts will not help you lose weight. And it won’t help you avoid disease.
#5: It’s Linked to Other Chronic Diseases
In addition to heart disease and obesity, there are many other diseases linked to high-linoleic veggie oils such as peanut oil. Here are three:
Eating high linoleic oils — especially when they’re oxidized — is a surefire way to increase oxidative stress.
This oxidative damage — and the associated inflammation — can eventually transform normal cells into cancer cells. Then tumors start to form[*].
#2 Liver Disease
More and more Americans are developing a condition called non-alcoholic fatty liver disease (NAFLD). Fat builds up in the liver, which causes a number of issues, from abdominal swelling to full-on liver cirrhosis[*][*].
How does NAFLD develop? Many factors: high-carb diets, metabolic syndrome, and yes, vegetable oils[*].
Consuming extra virgin olive oil, on the other hand, appears to improve liver health[*].
Type 2 diabetes presents as obesity, insulin resistance, and hyperinsulinemia. High-carb diets may contribute to diabetes, low-carb ketogenic diets may help reverse it[*].
High-linoleic vegetable oils are also linked to type 2 diabetes[*].
Practical Tips for Choosing the Right Cooking Oils
Peanut oil may have a delicious nutty flavor, and the unrefined, cold-pressed version may even have some healthy vitamin E.
But it’s also easily oxidized. This means it can throw off your O6:O3 ratios and contribute to conditions such as heart disease, metabolic disease, and obesity.
Instead of choosing PUFAs, use these tips to find the right cooking oils for you:
#1 Cook With Stable Oils
Peanut oil and other vegetable oils are sold as heat-stable oils, but they easily oxidize at high heat.
Instead, choose more stable cooking oils — saturated and monounsaturated fats like coconut oil, butter, palm oil, and avocado oil. The lipids won’t oxidize, and they’re delicious.
#2 Ask About Oils at Restaurants
Many restaurants — especially those serving Asian-style cuisine — use peanut oil to fry food. It tastes good.
But it’s not worth the damage. Ask if the chef can use healthier cooking oil, like olive oil, butter, or ghee.
#3 Mind Your O6:O3 Ratio
Recall that a high O6:O3 ratio is linked to a higher risk of obesity. Fortunately, you can improve your ratio by:
- Eating less O6 fats — peanut oil, soybean oil, safflower oil, etc.
- Eating more O3 fats — found mostly in fish, fish oil, and grass-fed beef.
Even if your ratio isn’t 1:1, having a 2:1 or 3:1 ratio is still better than most.
#4 Choose the Best Keto Fats
Whether you’re on a ketogenic diet or not, it’s a good idea to choose healthy fats.
Here’s what that might look like:
Bottom Line: Avoid Peanut Oil
Peanut oil may be delicious, but that distinctive flavor comes at a cost to your health.
Cooking with this oil generates oxidized lipids — molecules known to cause heart disease. Consuming peanut oil means eating linoleic acid — a PUFA that spikes your O6:O3 ratio.
All things considered, one thing is clear: the AHA is wrong about polyunsaturated fat. It should not be a dietary staple.
Instead, always opt for healthy fats. These fats support balanced hormones and neurotransmitter production, plus they’re part of a healthy keto diet.
Want to learn more about keto? Start here.