They are known to their numerous outspoken critics as “the hateful eight.” Refined oils derived from the seeds of specific plants, such as canola, corn, and sunflower oils, have become popular among politicians and wellness gurus.
They are “unknowingly poisoning” Americans, according to Robert F. Kennedy Jr. Influencers, blogs, and online forums claim that they are “toxic,” “slowly killing you,” and increasing the prevalence of chronic conditions like diabetes and obesity.
Nutrition scientists, who view seed oils as a significant improvement over butter and lard, find the notion that they are destroying human health particularly offensive.
Consuming seed oils has been linked to improved health for decades, according to Stanford University medical professor Christopher Gardner.
He continued by saying that to imply contrary “just undermines the science.”
We sought experts to help us understand the ambiguity surrounding the effects of these oils on our bodies.
Seed oils: what are they?
Refined plant-based vegetable oils are now commonly referred to as seed oils. The “hateful eight” oils, which also include rice bran, cottonseed, soybean, safflower, and grapeseed oils, are not all technically derived from seeds. For instance, a bean is used to make soybean oil. Additionally, some seed oils are not included in that list, such as flaxseed and sesame oils.
Unsaturated fats make up the majority of these oils. The majority of them had low levels of omega-3 fatty acids and high levels of omega-6 fatty acids.
According to Eric Decker, a food science professor at the University of Massachusetts Amherst, seed oils are created by pressing the seeds to extract the oils. Stopping there results in a cold-pressed oil, similar to extra-virgin olive oil, which is high in healthy plant-based chemicals but is susceptible to smoke and deterioration when heated to high temperatures.
According to Decker, manufacturers typically use heat and solvents to further process the oils in order to extract more oil from the seeds. Additionally, they frequently eliminate some of the ingredients that can cause splattering, rancidity, disagreeable flavours, or a dark hue.
According to Decker, these procedures provide an oil with a neutral flavour that is reasonably shelf stable and suitable for usage at high temperatures without readily smoking.
Why is the relationship between seed oils and health controversial?
Experts said that despite a number of concerns that have been brewing online, the research does not support any of them.
According to some critics, their increased proportion of omega-6 fatty acids compared to omega-3 fatty acids may exacerbate chronic illnesses by causing the body to become more inflamed. William Harris, a professor of basic biomedical sciences at the University of South Dakota, stated that this is predicated on an overly straightforward notion.
For instance, it is true that our systems can turn some omega-6 fatty acids into inflammatory chemicals, but they can also alter them into anti-inflammatory ones. Additionally, studies have shown that individuals with higher omega-6 fatty acid intake typically do not have higher blood markers of inflammation. Rather, they are healthier
Numerous studies have actually demonstrated that individuals who consume more omega-6 fatty acids or who have greater blood levels of those fats are less likely to die young and to suffer from cancer, Type 2 diabetes, cardiovascular disease, and other diseases.
According to Alice H. Lichtenstein, a professor of nutrition science and policy at Tufts University, clinical studies have also repeatedly demonstrated that people’s LDL, or “bad,” cholesterol levels and risk for cardiovascular disease drop when they substitute seed or other plant-based oils for some saturated fats (found in animal fats like butter or lard).
Additionally, detractors claim that the fatty acids in seed oils readily break down into smaller compounds that can harm cells when refined, stored, or cooked.
According to Decker, oils that are heavy in omega-6 and omega-3 fatty acids do degrade more quickly than solid fats, but the refining process and their high antioxidant content of vitamin E help to slow down that process. According to Decker, seed oils can spoil if left at room temperature for several months, just as many other food items. (He keeps his in the fridge.) If so, they ought to be discarded.
Last but not least, we’re consuming more of these oils than we used to, which is contributing to an increase in several chronic illnesses. For instance, one study discovered that during the last 50 years, the amount of linoleic acid, the primary omega-6 in seed oils, in American adults had more than doubled.
However, correlation is not the same as causation. Since ultraprocessed and fast meals now account for a greater portion of our diets than they did in previous decades, we’re consuming more of these oils, Gardner said. He stated that although some foods are unhealthy, there is no proof that their unhealthfulness is due to the presence of seed oils.
Blaming them instead of the foods they’re in is simply strange,” Gardner remarked.
What’s at stake here?
Eat less ultraprocessed foods if you want to cut back on your intake of seed oils, Gardner advised. That’s probably going to be a health win.