Are Raw Milk, Seed Oils, and Uncured Deli Meat Good for You?

These oils—which include canola, grapeseed, sunflower, and soy—are extracted from the seeds of plants. Critics say that their high levels of omega-6 fats raise inflammation in the body and that consuming them can lead to cancer, heart disease, type 2 diabetes, and other illnesses.

But the scientific evidence doesn’t support that. “In dozens of studies looking at omega-6s and inflammation, I haven’t seen one that shows an inflammatory effect, and roughly half of studies are showing anti-inflammatory effects,” Willett says. For example, a 2019 review of 30 studies, published in the journal Circulation, found that people with the highest blood levels of a type of omega-6 fat called linoleic acid had a 7 percent lower risk of cardiovascular disease, possibly because linoleic acid reduces inflammation. Plus, Willett says, we’ve known for decades that these oils also cut LDL (“bad”) cholesterol levels, and a higher intake of them has contributed significantly to the large decline in deaths from heart disease in the U.S.

Another argument that’s made against these oils is that hexane, a solvent used to extract the oil from the seeds, is toxic. “Hexane is a harmful compound,” Clifford says, “but the trace amounts that remain in the oil aren’t likely a concern.”

What may be a legitimate problem with seed oils stems from many of the products they’re found in. “Seed oils are used heavily in a lot of ultraprocessed foods,” Clifford says. “But the negative health effects of those foods aren’t from the oils themselves.” Cooking with seed oils or using them in salad dressings isn’t putting your health at risk.