Have you heard of the “Hateful 8?” No, it’s not a new crime series on Netflix. The “Hateful 8” is used in the blogosphere to defame the eight types of seed oils: Canola, Corn, Cottonseed, Soy, Sunflower, Safflower, Grapeseed, and Rice Bran. Seed oils are being blamed for everything from obesity to heart disease to autoimmune disorders to diabetes, but this reputation is undeserved.
Here’s What the Science Says
Seed oils, such as canola, corn, sunflower, and soybean oils, are rich in omega-6 polyunsaturated fats, which are essential for the body and can help reduce bad cholesterol levels, thereby lowering the risk of heart disease and stroke, according to the American Heart Association. However, they don’t play as much of a role in reducing cardiovascular risk as omega-3 fats (found in fatty fish like salmon and tuna or in walnut oil and flaxseed oil), which can give them a bad rap.
We Over Consume Omega-6 Fats
The challenge is that Americans tend to overconsume omega-6 fats, not because we’re cooking with them but because they are a key ingredient in most ultra-processed foods. (Think baked goods, chips, frozen meals, and packaged sauces and dressings.) We’re eating a lot more omega-6 than omega-3 fats, and we’re getting them from foods laced with other ingredients like high-fructose corn syrup, added sugar, and sodium.
Do Seed Oils Cause Inflammation?
While omega-6 fats are sometimes criticized for being pro-inflammatory, “the amount of inflammation associated with them has not been shown to be harmful,” says Stanford nutrition scientist Dr. Christopher Gardner. He points out that the real concern should be the overconsumption of ultra-processed foods. In these foods, seed oils aren't the problem; it’s the overall dietary pattern. The focus should be on achieving a healthy balance of omega-6 and omega-3 fatty acids rather than avoiding seed oils outright.
What About Seed Oil Processing?
In food production, a chemical called “hexane” is used to extract edible oils from seeds and vegetables. The trace amounts of hexane used to extract seed oils “do not make these oils harmful,” per Dr. Gardner.
What About Cooking?
Using seed oils for cooking, such as stir-frying vegetables with sesame oil, is fine. You can also enjoy them in a salad dressing. These are small amounts. You’re not drinking seed oils (at least, I hope you’re not!)