Why industrial seed oils make you fat

Author: Dr. Michelle Durkin on 4 July 2017


Everyone knows that trans-fats are bad for our health, but what about so-called vegetable oils?

Soy and canola oil, as well as less familiar products like corn, peanut, sunflower, safflower, and cottonseed oil, all fall under the term of “vegetable oils.” Kinda weird because they don't come from vegetables at all. This is just a marketing gimmick to make them sound a lot healthier than they really are. In the food industry “vegetable oil” just means “anything that isn’t an animal”.

Unlike actual vegetables, “vegetable oils” are not nutrient-dense whole foods. In fact, they’re so far from whole foods that you might wonder why we started eating them in the first place.

Well here's a little background:

  • Seed oils were a way to turn a profit from what would otherwise be waste. Cottonseed oil would have just been thrown out if Crisco had never been invented. Turning waste into “food” made it a gold mine.
  • Seed oils are cheap for the consumer because they’re made from agricultural surplus – just compare a bottle of canola oil to a bottle of olive oil.
  • The anti-saturated-fat campaign starting endorsing seed oils as healthy alternatives to lard and butter.

So what, why are seed oils a problem?

Seed oils contain high amounts of a type of polyunsaturated fat (PUFA) called Omega-6.

Omega-6 fats are chemically less stable than other types of fat. They break down easily under stress - especially when they’ve been exposed to heat, light, or oxygen. This causes a kind of damage called oxidation.

Oxidized fats are highly inflammatory and cause oxidative stress.

Now think about how we get our vegetable oils. First it sits out in a clear plastic bottle on the shelf, then it’s heated during cooking... Are you starting to see the problem?

Inflammation and oxidation is even worse when Omega-6 fats aren't in the right proportion to the Omega-3 fats. The ideal ratio of Omega-6 to Omega-3 is somewhere between 1:1 and 4:1. It is estimated the current Omega-6 to Omega-3 ratio in the North American diet is around 20:1.

This creates a perfect storm for chronic inflammation, oxidation, and the development of inflammatory diseases. Think cancer, cardiovascular disease, depression, diabetes, arthritis, and obesity, just to name a few.

Besides causing inflammation, which can make you fat, they also do this:

Vegetable oils contribute to an overproduction of neuromodulatory lipids called endocannabinoids. These chemicals are responsible for signaling hunger to your brain. In other words, they give you the munchies. No wonder you can’t stop eating that jumbo bag of chips!

What should we be eating instead?

Real food instead of agricultural waste. This includes oils like olive oil, avocado oil, coconut oil, and even butter (try ghee if you are dairy sensitive). I even keep a mason jar of bacon grease in my cupboard for certain recipes. Shocking!

Now I would love to hear from you! What foods could you be over-eating because they have industrial seed oils in them? Leave a comment below and I will be back next week with another edition of Doctor as Teacher Tuesday.

4 Replies to “Why industrial seed oils make you fat”

Lynn Siegner

Great article. I am sending it to many people that I care about!

Thanks Michelle.

Anna Matiowsky

What about Grapeseed oil?

Dr Michelle Durkin ND

Great to hear Lynn!

Dr Michelle Durkin ND

Grapeseed oil can be tricky because it has a high amount of PUFAs like other vegetable oils. The benefit is that it has a high smoke point so it take a lot more heat to create oxidation and any of the negative effects. I would still use it, but not frequently. I do not currently have it in my cupboard.

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