There is widespread speculation that seed oils are harmful to human health and are partially to blame for the rising rates of chronic disease. But when you look at the body of research on seed oils and health, the narrative is completely different than what you see on social media. Overall, studies show:

People who have a higher intake (to an extent) of seed oils actually have better health outcomes. 

Here’s my current understanding of the science after listening to a handful of conversations between experts in the field:

The main dietary component found in oil is fat. Seed oils are primarily composed of unsaturated fats; specifically, mono and polyunsaturated fats. Most seed oils contain higher amounts of polyunsaturated fats compared to monounsaturated fats, though the ratios vary widely between oils.

The compound within seed oils that has been villainized is linoleic acid (LA), an omega-6 polyunsaturated fatty acid. Due to an oversimplification of the science, there is a common misconception that LA is proinflammatory and that increased consumption of this fatty acid leads to high levels of inflammation and oxidation within the body.

It’s true that once inside the body, LA can be converted to arachidonic acid (AA), a precursor to proinflammatory compounds (which are essential for coordinating the body’s rapid response to acute insults, like infection or injury). But LA is also involved in many other cell signaling pathways that have anti-inflammatory effects. Just because you eat more LA, doesn’t mean you automatically increase AA levels; and even if you do get a rise in AA, it doesn’t mean it will lead to an increase in proinflammatory compounds or high levels of inflammation. The reality is, human physiology is extremely complex.

Dr. Bill Harris, a leading expert on dietary fats and cardiovascular health, sums it up best:

“It is much too simple-minded to say that LA is proinflammatory. We can’t look at a simplified pathway and think that we understand biology. There are so many other downstream pathways that aren’t accounted for [. . .] This story really emphasizes the need for scientific humility. We know what we know (all that we can see), but we don’t know what we don’t know. What else is happening below the surface?“ – The Proof Podcast (episode 357)

The Gist: Long-term data finds that people with higher levels of LA in their tissues have a lower risk of heart disease, cancer mortality, and total mortality. Based on this evidence, it seems a moderate consumption of seed oils is safe and can be part of a health-promoting diet. 

As with everything in life, nothing is for certain. As time goes on, new information will emerge that helps further our understanding of this topic. If new evidence comes along that’s in conflict with my current take on seed oils, I’ll adjust my views accordingly.

For a deeper dive on seed oils, I highly recommend listening to the following podcast episodes:

The Proof Podcast: Seed Oils: Dangerous or Misunderstood?

The Rich Roll Podcast: The Ultimate Case for a Plant-Based Diet: Busting Nutrition Myths Around Seed Oils, Soy, Protein, & More

The Dr. Hyman Show: The Truth About Seed Oils & What’s Actually Making Us Sick