RFK Jr. slams seed oils but research links them to lower risk of mortality and cancer

Robert F. Kennedy Jr. met major food companies on Monday, according to a Politico report, which means front-of-pack nutrition labels, seed oils, and food additives could have been discussed.

The Health and Human Services secretary has criticized the food and nutrition industries for harming Americans’ health. He also claims restaurants “unknowingly poison” consumers with seed oils.

In his post on X, Kennedy notes: “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 made because saturated animal fats were thought to be unhealthy, but we have since discovered that seed oils are one of the driving causes of the obesity epidemic.”

“Interestingly enough, this [obesity epidemic] began to drastically rise around the same time fast food restaurants switched from beef tallow to seed oils in their fryers… People who enjoy a burger with fries on a night out aren’t to blame, and Americans should have every right to eat out at a restaurant.”

Seed oil debate 

According to Walter Willett, professor of Epidemiology and Nutrition at T.H. Chan School of Public Health, some consumers worry that seed oils cause inflammation.

Kennedy claims restaurants “unknowingly poison” consumers with seed oils.“The idea that omega-6 fatty acids are pro-inflammatory is propagated over and over again on social media. Dozens of studies have looked at this, and about half show no effect, while the other half show a reduction in inflammatory factors.”

Dr. Christopher Gardner, professor of medicine at Stanford University and nutrition scientist at the Stanford Prevention Research Center, argues that it’s misleading to think omega-6 fatty acids break down into toxins when exposed to high temperatures, causing chronic illness. 

He asserts that the level of inflammation linked to the oil is not harmful and the benefits outweigh the potential health risks.

Meanwhile, the American Heart Association highlights that omega-6 is a polyunsaturated fat that the body cannot produce. It lowers bad cholesterol, lowering the risk of heart disease and stroke.

“Seed oils are a very healthy part of a diet, and when you look at some of the alternatives — like butter or lard — these are much better,” adds Willett.

Research backs plant-based oil health benefits

Vegetable oils are widely used and common seed oils are canola, soybean, and corn oil. Butter contains more saturated fatty acids and plant-based oils contain more unsaturated fatty acids.

Replacing 10 g — less than a tablespoon — of butter per day with the same number of calories from plant-based oils could reduce mortality and cancer deaths by 17%.A new study of dietary habits suggests that eating more plant oils and less butter could lead to better health. More than 200,000 people were tracked for over 30 years, and those consuming more seed oils like soybean and canola next to olive oil had lower mortality than those consuming high butter. 

Published in JAMA Internal Medicine, the study found the risk of cancer and cardiovascular disease was also low in those who consumed more plant oils.

“What’s surprising is the magnitude of the association that we found — we saw a 17% lower risk of death when we modeled swapping butter with plant-based oils in daily diet. That is a pretty huge effect on health,” says lead author Yu Zhang, MBBS, research assistant at the Channing Division of Network Medicine at Brigham and Women’s Hospital.

The research revealed those who ate mostly butter had a 15% higher risk of dying than those who ate the least. And those who ate most plant-based oils had a 16% lower risk of death than those who ate the least.

“Even cutting back butter a little and incorporating more plant-based oils into your daily diet can have meaningful long-term health benefits,” adds Zhang, also a student in the Department of Epidemiology at Harvard Chan School.

Researchers discovered that replacing 10 g — less than a tablespoon — of butter per day with the same number of calories from plant-based oils could reduce mortality and cancer deaths by 17%.

“Seed oils continue to make headlines and fuel national discussions and debates. We see this as an education opportunity — especially from food and nutrition experts such as registered dietitians nutritionists, who can play a key role in addressing misconceptions as well as helping consumers build healthy dietary patterns and habits,” comments the International Food Information Council’s (IFIC) president and CEO Wendy Reinhardt Kapsak, MS, RDN.

IFIC says heart-healthy monounsaturated and polyunsaturated fats — such as alpha-linolenic acid, an omega-3 fatty acid known to promote cardiovascular health — are abundant in canola and soybean oils.

Most Americans (46%) believe seed oils are healthy, 13% are unhealthy, and 17% don’t think they’re healthy or unhealthy, leaving 25% with no health opinion.What Americans think of seed oil 

According to IFIC’s recent study, most Americans (46%) believe seed oils are healthy, 13% are unhealthy, and 17% don’t think they’re healthy or unhealthy, leaving 25% with no health opinion.

Only 3% of participants believe margarine, pork fat, or palm oil are healthiest, while 56% say olive oil is their top choice, followed by vegetable oil 41% and butter 38%.

“In recent years, the topic of seed oils has become somewhat controversial, with many media headlines — driven by politicians, policymakers, and online influencers — thrusting these dietary fats into the spotlight,” says Kapsak.  

While 28% of Americans claim to avoid seed oils, more than 70% do not actively avoid them, according to the study. Of those who said they avoid seed oils, six in ten believe seed oils are more processed (63%), more genetically modified (62%), and cause weight gain/obesity (61%) than other oils.

Despite being one of the most researched nutrients, dietary fats, including seed oils, have long been scrutinized, with some believing they are inflammatory and cause cardiovascular disease.

According to the study, 25% of Americans have never heard the term “seed oils,” 19% say they see it often, and 18% say they encounter it sometimes. Common sources of seed oil information come from friends and family (24%) and social media (22%) — but not per se from food or nutrition science.

“There’s clear consumer confusion around seed oils,” says IFIC senior director of Research & Consumer Insights, Kris Sollid, RD. “People are hearing the term but are unsure which oils qualify as seed oils. This makes it that much easier for misinformation to spread about oils and what it means to eat healthy.” 

In other public health news, the Center for Science in the Public Interest is scrutinizing US FDA commissioner Dr. Marty Makary, worried about Tesla Motors CEO Elon Musk’s and Kennedy’s influence on public health and food safety. Kennedy recently came under fire for promoting vitamins amid a measles outbreak.