Cotton isn’t a vegetable. It’s what your shirt, pants, and underwear are made of.
But cottonseed oil, harvested from the seeds of the cotton plant, is considered a vegetable oil. According to the American Heart Association, this vegetable oil — high in polyunsaturated fat and low in saturated fat — is a “healthy cooking oil” that’s good for your heart[*].
The AHA is an influential organization, and many people follow their recommendations. But the real question is: Should you cook with this oil?
History Of Cottonseed Oil
Until the late 1800s, nobody cared much for cotton seeds. Cotton fiber was in demand, and the useless seeds were thrown away[*].
But near the turn of the century, Proctor and Gamble sensed a business opportunity and started incorporating cheap cottonseed oil into their products. This effort culminated with the 1911 launch of Crisco — a vegetable shortening now synonymous with the term trans fat[*].
Over the next 30 years, cottonseed oil replaced lard in many recipes and became the king of vegetable oils.
However, by World War II, this oil was on the way out and soybean oil was on its way in. Why? Simple economics. Soybean oil was cheaper[*].
By the 1950s, vegetable oils were somewhat popular — but thanks to a doctor named Ancel Keys, they were about to get much more popular.
That’s because, in 1955, Keys unveiled his thesis that saturated fat caused heart disease. It wasn’t based on good science, but it still gained traction[*].
And so, in the name of a healthy heart, the AHA began recommending that people replace saturated fats with polyunsaturated fats. Soon, vegetable oils were known as being heart healthy, while saturated fats such as lard, coconut oil, palm oil, and eggs became synonymous with heart disease[*].
Unfortunately, the AHA still has it wrong[*]. Vegetable oils are not good for your health.
Healthy Fatty Acids
Fat is not just one molecule, but many. And the structure of a fatty acid depends on the number of unfilled hydrogen bonds on the molecule.
Saturated fatty acids (SFA), for instance, are saturated with hydrogen bonds. Easy enough to remember.
A brief word on saturated fat and heart disease: Ancel Keys — the father of the low-fat theory — based his hypothesis on population data. These were correlations between country-wide dietary data and rates of heart disease[*]. However, correlation is not the same as causation.
The truth is, to avoid saturated fat is to avoid some of the most nutrient-dense, healthy oils out there. Eggs for choline, meat for iron and zinc, sustainably-sourced red palm oil for vitamin A. These are all food-based nutrients you don’t want to miss out on.
Moving on from SFA, the much-celebrated monounsaturated fatty acids (MUFAs) have one open hydrogen bond and are widely considered healthy. MUFAs like olive oil, avocados, and palm oil appear to support healthy blood glucose levels, blood pressure, and cardiovascular health[*].
Cottonseed Oil 101
Cottonseed oil has a long history, and the story continues to unfold today. The oil is ubiquitous, not only for cooking, but as an ingredient in shortenings, salad dressings, and other food products in the center aisle of grocery stores nationwide.
Where do cotton seeds come from? Often from India, where cotton crops account for 38% of the country’s exports[*].
What Is Cottonseed Oil?
Cottonseed oil is pressed from the seeds of cotton. After pressing, the oil goes through an extensive refining process. This process removes, among other compounds, gossypol — a potent toxin shown to suppress spermatogenesis (sperm production) in mice and men[*].
The refining process also removes vitamin E — a potent antioxidant and free radical scavenger[*] — from the oil.
Refined cottonseed oil has the following fatty acid profile[*]:
- 27% saturated fat, mostly palmitic acid
- 18% monounsaturated fat, mostly oleic acid
- 55% polyunsaturated fat, mostly linoleic acid
This oil from the seeds of cotton is mostly PUFAs, which is highly unstable. That means the fat oxidizes when exposed to light and heat. This means that most of the oil goes rancid before you even buy it.
Decades ago, to make the product more heat stable, manufacturers used to hydrogenate the PUFA in cottonseed oil.
Hydrogenation is a chemical process where manufacturers add hydrogen to make oil more solid at room temperature. The only problem is that hydrogenated or partially hydrogenated oils contain trans fatty acids.
Not only are trans fatty acids linked to many chronic diseases including coronary heart disease[*], they’re also the only type of fatty acid in food that you don’t find in nature.
Trans fats are so bad that the World Health Organization requested that governments remove them from the international food supply[*]. The United States was a slow adopter, but in 2015 the FDA recognized that partially hydrogenated oils were no longer “generally recognized as safe” for human consumption[*].
4 Reasons to Avoid Cottonseed Oil
#1: Negatively Impacts Your Heart
Many so-called health experts have sanctioned cottonseed oil as a quality cooking oil because of its moderate SFA content, which is more stable than soybean or sunflower oil.
But more stable doesn’t mean stable. When an oil contains 55% linoleic acid, you can be sure that the oil will oxidize when exposed to high temperatures.
And oxidized oils aren’t good for your health. Oxidation means that the fats are infiltrated by oxygen, thereby changing the chemical composition — and health effects — of the oil[*].
What’s more, eating oxidized lipids (from fried vegetable oil) accelerates the progression of heart disease[*]. Oxidized lipids mean a higher risk of heart disease. The more you consume, the higher your risk.
Strangely, however, the AHA continues to recommend vegetable oils for cooking[*].
#2: Omega-6 Oils Can Cause Inflammation
Omega-3 and omega-6 fatty acids are PUFAs. Some of these PUFAs — like the omega-3s EPA and DHA — are called essential fatty acids because you need them and your body can’t synthesize them on its own. They must come through diet.
Omega-3s — found mostly in seafood and certain seaweeds — reduce inflammation and support cognitive health[*]. They are, in large part, why fish is so good for you.
Omega-6s like linoleic acid also serve important functions, but these days Americans are eating way too many omega-6s.
Researchers believe that people evolved to eat about a 1:1 ratio of omega-6 to omega-3. The standard American ratio? Closer to 20:1[*].
This ratio is a recipe for inflammation. All those omega-6s increase oxidative stress, which in turn, overworks your immune system.
But unless you’re sick, you don’t want inflammatory immune particles around. This low-grade immune response — the dreaded “systemic inflammation” — underlies most chronic diseases: heart disease, neurodegenerative disorders, diabetes, and even cancer[*].
#3: Omega-6 Oils Are Linked to Obesity
Research shows that a high O6:O3 ratio is also a recipe for obesity.
In one study, two groups of mice were fed two diets: a standard American diet (high linoleic) and pre-1970s American diet (low linoleic). The mice fed a high linoleic diet — just like most American diets today — became obese[*].
Here’s why. Once digested, linoleic acid is converted to arachidonic acid — another O6 fat.
Arachidonic acid is a troublemaker. It activates your endocannabinoid system, flipping on the “get fat” switch. It tells your body to start gaining weight. Now.
How does cholesterol factor in? Here’s the confusing part: high linoleic vegetable oils — cottonseed oil included — seem to lower cholesterol levels
Isn’t that good for your heart?
#4: Cottonseed Oil May Raise Your Cholesterol
Several studies show that vegetable oils moderately lower total cholesterol (TC) and LDL cholesterol (LDL-C) levels[*][*]. Many have relied on this research as proof that cottonseed oil is good for your heart.
But total cholesterol and LDL-C are unreliable predictors of heart disease risk.
LDL particle number — the number of low-density lipoproteins (LDL) particles in your bloodstream — is the more reliable metric[*].
Here’s why LDL-C is unreliable (and LDL-P is not):
- When LDL-P is high, and LDL-C is low, a person is at high risk for heart disease
- When LDL-P is low, and LDL-C is high, a person is at low risk for heart disease
When there’s discordance, LDL-P predicts risk. If you only measure LDL-C, you may get misleading data.
All the positive cholesterol data on PUFAs is on LDL-C, not LDL-P. In other words, it’s not up-to-date with current cardiovascular risk markers.
That’s not all. Earlier you learned how oxidized lipids can damage your heart. Oxidized LDL isn’t on your standard lipid panel, and it’s fairly easy to ignore.
But your body can’t ignore oxidized lipids from fried cottonseed oil. They’re simply too damaging.
There’s one more lipoprotein — a type of LDL particle called Lp(a). Call it lipoprotein A, or by it’s more common parlance, L-P-little-a.
Think of Lp(a) as the super-atherogenic LDL particle. If you don’t want LDL particles in your arteries, you really don’t want Lp(a) particles there[*].
Eating partially hydrogenated fats, which cottonseed oil often is, can raise levels of Lp(a)[*]. Not good.
How to Choose the Right Fats
It’s time to meet the right fats. They’re high in heat-stable MUFAs and SFAs, and low in easily-oxidized PUFAs like linoleic acid.
The right fats are perfect for the ketogenic diet — a high-fat, low-carb style of eating that helps you stay lean, focused, and full of stable energy.
Other keto-approved fats include eggs, animal fat, ghee, cottage cheese, whipping cream, and the list goes on.
The Verdict On Cottonseed Oil
Some circles still think of cottonseed oil as a healthy cooking oil. Some say it lowers cholesterol and improves heart health.
But while the cholesterol claim is narrowly true, the heart health claim is clearly false. Cooking with cottonseed oil generates oxidized lipids, and these oxidized lipids end up in your arteries.
Cottonseed oil is also antithetical to weight loss goals. Too much linoleic acid? Hello, weight gain. This has been shown in mice — and on a massive scale, in the American population[*].
But don’t get down on eating fat. Even if cottonseed oil is bad for you, many keto-approved fats are extremely healthy.
So toss some butter in a pan, add some MCT oil to your smoothie, scoop some nut butter into your mouth. Your body — and your taste buds — will be glad you did.