Seed oils under fire: Why RFK Jr. and influencers are sounding the alarm on fast-food restaurants

Thanks chiefly to President Trump’s pick as the country’s new health secretary, seed oils are at the center of a debate that has reached boiling point in the United States.

Seed oils poisoning Americans, RFK claims

Robert F. Kennedy Jr., who in February was sworn in as the head of the U.S.’s Department of Health and Human Services, has made the claim that Americans are being “unknowingly poisoned” by seed oils.

In a post on the social-media platform X in October, Kennedy called on U.S. fast-food restaurants to stop using seed oils in their fryers, writing: “Fast Food is a part of American culture. But that doesn’t mean it has to be unhealthy, and that we can’t make better choices.”

The 71-year-old, who is a son of the former presidential candidate Robert F. Kennedy, added that restaurants such as McDonald’s should revert to using beef tallow in their cooking process.

And Kennedy’s calls against seed oils have been seconded by prominent social-media personalities such as the fitness influencer Brian “Liver King” Johnson. Per the Food Institute, Johnson has described seed oils as “dangerous” and “destructive” to human health.

Fast Food is a part of American culture. But that doesn’t mean it has to be unhealthy, and that we can’t make better choices. Did you know that McDonald’s used to use beef tallow to make their fries from 1940 until phasing it out in favor of seed oils in 1990? This switch was… pic.twitter.com/ygijMtsSQt

— Robert F. Kennedy Jr (@RobertKennedyJr) October 21, 2024

So what are seed oils?

As explained by the Food Institute, seed oils – which are also known as vegetable oils – are oils extracted from the seeds of plants. Used for cooking and processing food, seed oils come with a clear price advantage for consumers over fruit oils such as olive oil.

Why are seed oils said to be harmful?

Eight seed oils – canola, corn, cottonseed, grapeseed, soy, rice bran, sunflower and safflower – have now been dubbed the “Hateful Eight” by their detractors.

Seed oils have mainly come under fire because they are high in omega-6 fatty acids, the Food Institute explains. This has led seed oils’ opponents to claim they are responsible for causing inflammation, weakening people’s immune systems and contributing to the development of chronic illnesses.

What is omega-6?

Per the American Heart Association (AHA), omega-6 is a polyunsaturated fat that the human body needs but is unable to make by itself. Notably, omega-6 helps to reduce the amount of LDL cholesterol – a waxy, fat-like substance also known as “bad” cholesterol – that is in our system.

Is omega-6 being “overdone” or “unfairly demonized”?

In an interview with the Scientific American in December, the University of Florida professor of surgery Timothy Yeatman claimed that the U.S. population may be getting too much omega-6 in its daily diet.

“It’s like everything else: it should be in moderation,” Yeatman said. “But the problem is we’ve massively overdone the amount of seed oil in foods.”

Yeatman added: “Someone needs to prove that seed oils, taken in the excess amounts they’re given to us, are truly safe. And that hasn’t been proven yet to me, so I think the default should be reduce them until you know.”

Citing Dr. Christopher Gardner, a nutrition scientist at the Stanford Prevention Research Center, the AHA has countered that omega-6 is being “unfairly demonized”, in part because it is slightly less effective at protecting human health than a similar substance known as omega-3.

Dr. Gardner argues, for example, that the amount of inflammation caused by omega-6 has not been shown to be harmful.

What’s more, when it comes to the ultra-processed items that typically make up fast-food meals, we should not be focusing on the seed oils used in the process of making them, Dr. Gardner says. “It’s hard to cast the blame on the seed oils when these foods contain so many other things,” he told the AHA.

F.D.A. nominee calls for “consolidation of scientific evidence”

Speaking at a Senate hearing last week, Dr. Marty Makary, President Trump’s nominee to lead the U.S.‘s Food and Drug Administration, called for further research to be carried out into the effects of seed-oil products.

“I think seed oils are a good example of where we could benefit from a consolidation of the scientific evidence,” Dr. Makary, a health care expert at Johns Hopkins University, said, per the Associated Press.

And what about beef tallow?

According to the Mayo Clinic, beef tallow is a “whiteish substance” made “by removing, simmering and clarifying the fatty tissue that surrounds the organs” of cows.

Eric Decker, a food science professor at the University of Massachusetts Amherst, disagrees with Kennedy that restaurants should switch to beef tallow for cooking methods such as deep frying.

“There is no evidence to indicate that beef tallow is healthier than seed oils,” Decker told AP.