Does Linoleic Acid (Soybean Oil) Make You Sick

January 08, 2024

Does Linoleic Acid, (Soybean Oil) Make You Sick?

The number one seed oil in the world today that is added to our food is soybean oil. That's because it is so easy to grow millions of acres of soybeans, and we like fat. It is a necessary fat that we don't make ourselves. You could call it a vitamin. Our mitochondria need it to make the cardiolipin on which all the enzymes sit for the electron transport chain. Soybean oil is 20-54% linoleic acid, so that is one very rich source. Sunflower, corn, and safflower are also rich sources. Sounds like a marriage in heaven. The American Heart Association has even recommended that we get 5-10% of our calories from "unsaturated fat" like linoleic acid.

As we have industrialized our food chain, ultra-processed foods have become dominant and we now have pretty good evidence that ultra-processed foods lead to diabetes, heart disease, and obesity....all of our modern afflictions. The simplest definition of an ultra-processed food is a processed grain (or potato) with added soybean oil, added sugar, and added salt. There you have it. The linoleic acid in our diet used to be about 1%. With the advent of our modern industrial food supply, we are hitting 9-10% of our calories from soybean oil/linoleic acid.

Does something change when we do that? Well, yes. The devil may be in the details. A study from the University of California, looking at the gut microbes in mice when fed a high linoleic acid diet found some disturbing findings. The development of "adherent E. coli" on the wall of the gut was matched by the die-off of several species of helpful bacteria. Furthermore, the gut wall became porous leading to increased gut inflammation. This was in mice but there is no shortage of humans who will tell you their IBS got better when they monitored and reduced their linoleic acid (soybean, corn, safflower) oil and added olive oil or avocado instead.

There may be other problems. For example, there is now serious consideration that cooking with high heat oils in China contributes to non-smoking lung cancer. Or, if you want to do a deeper dive you can get into OXLAMs, the oxidized forms of linoleic acid that inevitably show up with high-heat cooking. OXLAMs are poisons and have been linked to mitochondrial dysfunction, fatty liver, and a long list of other metabolic maladies.

There are links to diabetes, fatty liver, and Alzheimer's. I think the list is getting longer and a bit more concerning. It's time to call a time-out. My guess is the American Heart Association got it wrong when they recommended that much linoleic acid. I smell the rancid smell of big industry lobbying the AHA. There is no question we need a teeny, tiny bit. Just right. But not too much. It's that oxidation that happens with high heat that makes the poison. I suspect the formula of healthy, organic, whole foods will give you just that.

www.What will Work for me? Everywhere I look I find corn, soy, safflower, sunflower, or some other seed oil. Linoleic acid is everywhere. My salad dressing is an obvious one. But the quick stir-fry mix from Trader Joe's? Yup. The luscious butter Christmas cookies? Yup. I need a bit of it. It's the stir fry and high heat that makes from trouble....and just plain too much of it.

References: Harvard Chan Public Health , Scientific Reports, Gut Microbes, Onco Target Therapeutics, Journal of Lipid Research, Frontiers in Endocrine, Neurosci Letters,

Pop Quiz

1. What is linoleic acid?                                        Answer. A dietary necessity. It is a poly-unsaturated fat that is richly represented in seed and nut oils. 

2. What is the highest food source of linoleic acid?                                         Answer: Soy, corn, canola. safflower, and sunflower oils.

3. What happens to mice when you give them a high level in their diet?                                                Answer: They get leaky gut and irritable bowel, just like humans.

4. Can I avoid linoleic acid?                                               Answer: With effort. All ultra-processed foods are rich sources of them. If it comes in a plastic bag or a cardboard tin, it's likely problematic because most of that food is made with some sort of high heat.

5. Will my insulin resistance get better?                               Answer: Likely yes, and then you will start to lose that lousy poochy little tummy.