Seed oils: What they are and why your body actually needs them

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Joanna J. Parga-Belinkie, MD

September 3, 2025

What are seed oils?

Seed oils come from plants like sunflowers, soybeans and corn. The terms “seed oils” and “vegetable oils” are used similarly. All seed oils are in the larger category of vegetable oils but for example, avocado oil is not a seed oil (it’s not a seed). Seed oils are a source of essential (or necessary) fatty acids.

Why does the body need essential fatty acids? 

These are a group of fats the body can’t make, and that we need to eat in our diet. Fatty acids or fats help with cell functioning, and cells are the building blocks for our bodies. Different types of fats and the balance between them are important in regulating many things, including inflammation. Inflammation sounds scary, but it can and does do good things for our bodies. Examples are when it helps us heal when we are injured or recover from being sick with a cold or flu. We need some inflammation for our bodies to work well.

What are some concerns about eating seed oils? 

There is concern that seed oils give us too much of a fat that can invite or cause inflammation. This is in response to changes in our fat consumption that began in the 1960s. The fats used in fast food, packaged snacks and other foods common in the American diet slowly changed to being more plant- than animal-based. This move to plant-based fat in some ways remains popular because of concerns that animal fat increases cholesterol, which can be bad for heart health. What we have found since then is that the composition of fats in our bodies is more complex than simply saying high cholesterol leads to heart disease. We have also been learning about how a higher amount of things like seed oils in our diets affects cell function.

Some believe seed oils are the reason for things like chronic inflammation and disease in our society. Again, the science here is complex. Fatty acids are essential for our bodies, and some of those we need to get from our diet. Although we want to promote balance and discourage inflammation, we should not avoid seed oils because we need the fats they provide us. Remember they help with other cell functions besides inflammation, and we do need some inflammation for our body to help protect us. That’s why we don’t want to eliminate these fats from our diet; instead we should find a balance where we consume a healthy amount of them.

What are we still learning about fats and seed oils? 

There is ongoing research into how fats affect the health of major organs like the heart, brain and bones. We are still learning how much is too much when it comes to fats from seed oils. This does not make them dangerous. Every individual’s fat needs are different because everyone’s body processes fats differently. Avoiding seed oils altogether can have negative consequences. Eliminating them can cause problems like nutrient deficiencies and, in kids, overall poor growth, which may lead to worse health. This is an area where talking to a dietician or pediatrician can help you understand the different fats in your diet, and where you might be able to change the fats you eat to get all the nutrients you need.

Joanna J. Parga-Belinkie MD specializes in the care of newborn babies at the Children’s Hospital of Philadelphia and the Hospital of the University of Pennsylvania. She is a mother of three children and a co-host of Pediatrics On Call, the flagship podcast from the American Academy of Pediatrics.

Rachel Kofsky is a lead dietician at the Children’s Hospital of Philadelphia.

Denise Sievering is a clinical dietician specialist at the Hospital of the University of Pennsylvania.