# Linoleic Acid

Category: Foods & Substances

Also known as: LA, omega-6

Linoleic acid is a polyunsaturated omega-6 fatty acid that Ray Peat identified as a primary driver of degenerative disease, arguing that its designation as an “essential” nutrient was a marketing campaign built on flawed science. Peat traced the origin of the essential fatty…

11 passages · 2 authors · 1996–2025 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/linoleic-acid

## Synthesis

**Linoleic acid** is a polyunsaturated omega-6 fatty acid that Ray Peat identified as a primary driver of degenerative disease, arguing that its designation as an “essential” nutrient was a *marketing campaign* built on flawed science. [Source 2, 6] Peat traced the origin of the essential fatty acid concept to the Burrs’ experiments in 1929, noting that the Burrs themselves later demonstrated that adding linoleic acid back to a deficient diet **suppressed metabolism by about 50%**. [Source 1, 6] He emphasized that a human subject in the Burrs’ own lab lived for months on a diet devoid of linoleic, linolenic, and arachidonic acid, during which chronic conditions like migraines and hypertension disappeared. [Source 1] Peat maintained that cells can be grown indefinitely in culture without any polyunsaturated fats, which he considered proof that they are not essential nutrients. [Source 3, 5]

At a mechanistic level, Peat described linoleic acid as a systemic poison that disrupts thyroid function at every known level—**synthesis, transport, and cellular response**—with the degree of inhibition proportional to the number of double bonds. [Source 5] He cited research from 1964 showing that the most advanced atherosclerotic lesions contained the highest concentrations of linoleic acid, and that its oxidation products accumulate in degenerating tissue. [Source 3] Peat also connected linoleic acid to the formation of **prostaglandins**, which promote inflammation, and to the spontaneous oxidation of brain fats into *isoprostanes* and *neuroprostanes* that accompany Alzheimer’s disease. [Source 3, 7] He noted that the brain becomes increasingly polyunsaturated with age, and that the resulting prostaglandin activity contributes to tissue under-functioning. [Source 7]

Georgi Dinkov has extended Peat’s framework by documenting linoleic acid’s direct role in cancer progression. He highlighted a mechanism in which linoleic acid binds to and activates **FABP5**, an enzyme that facilitates PUFA uptake into cells and is highly correlated with poor prognosis in multiple cancers. [Source 8] Dinkov argued that linoleic acid functions as a *dietary carcinogen* not only through its role as a precursor to inflammatory prostaglandins and leukotrienes, but also through its own endocrine effects, which he described as mimicking estrogen—a known human carcinogen. [Source 8, 9] He noted that average American consumption exceeds 50 grams of linoleic acid daily, roughly 25 times the amount needed to satisfy any theoretical requirement, and that the rising curve of chronic disease closely matches the historical increase in omega-6 intake. [Source 4, 9]

Peat and Dinkov both rejected the industry pivot from omega-6 to omega-3 fish oils as a remedy. Peat explained that fish oil’s apparent anti-inflammatory effect is actually a *temporary immune suppression*, while in the long run it increases inflammatory and degenerative processes, as demonstrated by the yellow fat disease and brain degeneration observed in animals fed fish waste. [Source 2, 10] Dinkov added that genetically modified soy oil with low linoleic acid but high oleic acid still caused **fatty liver disease**, a pathology shared with olive oil, while coconut oil and fructose caused neither diabetes nor liver damage. [Source 11] Peat summarized the historical arc by stating that linoleic acid was ultimately recognized as essential for cancer, but not for nutrition. [Source 10]

## People also ask

### How does linoleic acid suppress metabolism?

Peat argued that linoleic acid disrupts thyroid function at every level—synthesis, transport, and cellular response—with the degree of inhibition proportional to the number of double bonds, and he cited the Burrs’ later finding that adding it back to a deficient diet suppressed metabolism by about 50%.

### Why did Peat consider linoleic acid a dietary carcinogen?

Peat and Dinkov described linoleic acid as a carcinogen because it activates the cancer-linked enzyme FABP5, serves as a precursor to inflammatory prostaglandins, and exerts endocrine effects that mimic estrogen, a known human carcinogen.

### Does fish oil counteract the harmful effects of linoleic acid?

Peat argued that fish oil’s apparent anti-inflammatory effect is actually a temporary immune suppression that ultimately increases inflammatory and degenerative processes, as shown by yellow fat disease and brain degeneration in animals fed fish waste.

## Related concepts

- [Age Pigment (Lipofuscin)](https://bioenergeticoracle.com/md/concepts/age-pigment-lipofuscin/index.md)
- [Arachidonic Acid](https://bioenergeticoracle.com/md/concepts/arachidonic-acid/index.md)
- [Benign Prostatic Hyperplasia (BPH)](https://bioenergeticoracle.com/md/concepts/benign-prostatic-hyperplasia-bph/index.md)
- [Butter](https://bioenergeticoracle.com/md/concepts/butter/index.md)
- [Cholesterol](https://bioenergeticoracle.com/md/concepts/cholesterol/index.md)
- [Chronic Fatigue Syndrome](https://bioenergeticoracle.com/md/concepts/chronic-fatigue-syndrome/index.md)

## Cited passages

Passage numbers match the `[Source N]` markers in the synthesis above.

### Source 1 — Ask the Herb Doctor: July 2020 KMUD

Ray Peat · Interview · Jul 17, 2020

> ## Linoleic Acid and Coronavirus Susceptibility
>
> **Andrew Murray:** Before we get into the subjects surrounding the pandemic, let me ask you about a recent pre-publication which implicates linoleic acid—an omega-6 compound found in vegetable oils, nuts, seeds, meats, and eggs. I know you've always opposed all PUFAs (polyunsaturated fatty acids) as being detrimental to health and pro-inflammatory. This article implies that linoleic acid is responsible for allowing the spike protein of the coronavirus to dock with the cell membrane, facilitating entry into the cell. This suggests that diets rich in linoleic acid—which have been pushed on populations for the last 40 years—may put patients at increased risk. What do you think about the paper?
>
> **Ray Peat:** It actually should be a revolutionary paper because it shows that linoleic acid is essential for forming the receptor binding site of the spike protein. The spike protein is the thing that makes this a more dangerous form of coronavirus than the common cold. If you can't form the crucial thing that makes it infective without linoleic acid, that has all kinds of ramifications. It has been known for 80 years—in a human experiment overseen by George Burr, who originated the idea that these fats are essential—that a person on a diet with absolutely no measurable level of linoleic, linolenic, or arachidonic acid saw their chronic health problems, such as migraines and hypertension, disappear after about four months.

### Source 2 — Energy Production Diabetes Saturated Fats KMUD 2011

Ray Peat · Interview · 2011 · http://www.l-i-g-h-t.com/files/herb-doctors-energy-production,-diabetes-and-saturated-fats.mp4

> **Ray Peat:** But the counter-evidence had included such things as many animal diseases; that degenerative brain diseases, atrophy of the gonads, and infertility, and so on, were connected with eating too much of the unsaturated fats. And vitamin E was found to protect against that. So, it was all marketing campaign to sell the idea that not only are those fats essential, but they're good for you, and like a drug they will prevent heart disease. But very soon, people started producing evidence showing that in fact linoleic acid not only causes heart disease, but promotes cancer, immune problems, all kinds of things similar to what they had seen in the animals.

### Source 3 — Effects of Stress and Trauma Eluv Radio 2014

Ray Peat · Interview · 2014 · http://l-i-g-h-t.com/files/eluv-effects-of-stress-and-trauma-on-the-body.mp4

> **Eluv:** What about soybean oil, because they‘re all GMO now?
>
> **Ray Peat:** It's still the polyunsaturated component, which is that it turns into prostaglandins, which promote all kinds of inflammation and degenerative diseases. As early as 1964, a Dutch researcher named Böttcher [reference: http://www.ncbi.nlm.nih.gov/pmc/article ... 4-0048.pdf] sliced open the lesions in atherosclerotic arteries at all different stages of development, and analyzed the fats in them. He called it a primitive idea that cholesterol got diffused out of the blood into the artery and damaged it. He said that the situation is very different from that; many fats change at the beginning, before the change happens in the cholesterol. And in the most advanced lesions — the furthest advanced atherosclerosis — he found that the content of linoleic acid was highest in the worst lesions. And after that, many other people demonstrated that the oxidation products of these unstable highly unsaturated fats are found increasingly in the atherosclerosis.
>
> **Eluv:** All of these oils – canola oil, soybean oil, high fructose corn syrup, butter substitutes — are being advertised as better for your health. It’s really about the consumers self-educating themselves and looking beyond the advertising.

### Source 4 — How the Wrong Dietary Fat Can Wreck Your Health - Discussion Between Georgi Dinkov & Dr. Mercola

Georgi Dinkov · Interview · Dec 18, 2022 · https://www.youtube.com/watch?v=icfBXeQSsq8

> **Dr. Joseph Mercola:** We're consuming a lot more than two grams daily. What's your perception of the amount? The confusion here results in how much linoleic acid is versus omega-6 because a lot of times there's distinction that's not made. I thought it was over 50 to 70 grams a day of omega-6 fat. Yeah, of course.
>
> **Georgi Dinkov:** I mean, if the average American is consuming 80 to 90 grams of fat daily, it used to be mostly saturated fat. It's not anymore. Now it's mostly PUFA. So if that, let's say if like 90% of that fat is PUFA and about 60 to 70% is linoleic acid, then you are getting like in excess of 50 grams of linoleic acid a day. That's massive, massive.
>
> **Dr. Joseph Mercola:** 25 times what you need. Yeah. And do you concur that that, or my belief that this is the primary culprit of almost all metabolic disease?
>
> **Georgi Dinkov:** Oh, and in fact, now that we're more able to start to accumulate that things like cancer and Alzheimer's and Parkinson's are also metabolic diseases, at some point we may be able to make the statement that it's omega-6 is the primary cause of all diseases. And furthermore, now that they're starting... science started to draw the parallel between diseases and aging. The primary risk factor for disease is what? Age, right? For chronic disease. So if they are the same process, it may very well turn out that omega-6 is at the core of our deterioration as organisms throughout life. Whether it's pathological or natural aging, as they call it, may turn out to be the same thing and nothing natural about it, maybe self-induced.

### Source 5 — Your Own Health And Fitness: Thyroid/Progesterone And Diet

Ray Peat · Interview · Nov 12, 1996 · http://www.l-i-g-h-t.com/files/your-own-health-and-fitness-thyroid-progesterone-and-diet -november-12-1996-57-mins.mp4

> **Ray Peat:** Omega-3 and Omega-6 are the things that people are currently conscious of because of vast marketing campaign that has been going on for 40 years, but when we aren’t given these things which inhibit these external unsaturated fats inhibit our own enzyme system and when we’re not saturated with these enzyme inhibitors, our own cells produce Omega-9 unsaturated fatty acids. Coconut oil and olive oil are very similar to what the baby produces when it's not – when it’s relatively insulated. And if you take cells and grow them in culture, they grow wonderfully in a completely unsaturated oil-free culture median showing that human cells whether in the developing fetus or in a laboratory dish do a fine job of producing unsaturated fat, and in fact have more cellular vitality than when they are exposed to these environmental oils.
>
> **Layna Berman:** Okay. Well, just again to make it accessible, what you’re really saying is to stay away from vegetable oils, correct?
>
> **Ray Peat:** Yeah. For example, the degree of unsaturation linolenic with three double bonds or linoleic acid with two double bonds in proportion to the number of double bonds, they poison the thyroid function at every known level of the synthesis, the transport and the response in two or three different ways inside the cells are strongly poisoned by the three unsaturated groups and significantly inhibited by the two double bonds of linoleic acid.

### Source 6 — The Science Behind The Dangers of Polyunsaturated Fats - East West Healing and Performance Interview (hosted by Josh and Jeanne Rubin)

Ray Peat · Interview · 2011 · https://www.youtube.com/watch?v=_AK-uiCWZPk

> **Ray Peat:** So, what the Burrs had demonstrated was that the Essential Fatty Acids slows metabolism, making them need less food, and so prevented a deficiency on a deficient diet. But given a diet without those fats, but with adequate Vitamin B6, there were no symptoms produced. But when the oil industry wanted to market their products (the metabolism-supressing fatty acids), they simply ignored the fact that the Burrs' work had been totally invalidated. And, now, 70-80 years later, they are still citing the work of the Burrs as the evidence that fatty acids (Linoleic and Linolenic) are essential. But now, for 65 years, it's been perfectly established that they are not essential.

### Source 7 — Thyroid, Hypothyroidism & Diet, Lifestyle, Exercise to Fix it!

Ray Peat · Interview · Jul 20, 2019 · https://www.youtube.com/watch?v=HNTgD6djJtE

> **Ray Peat:** of having the arachidonic acid prostaglandin rise as you accumulate fat with aging the brain gets more and more polyunsaturated fats and they're starting to look at the role of prostaglandin in brain has lots of spontaneous oxidation of fats into substances called isoprostanes and neuroprostanes, which are spontaneous equivalents of the enzyme produced prostaglandins, but they are made from both enzymes. in the stressed brain and go with our increase in Alzheimer's disease. Following the idea of essential fatty acids in the 60s, people were told to eat more linoleic acid because it's an essential fatty acid. When it was found that that was increasing both cancer and heart disease, the marketers turned to the fish oil type of N-3. But still, those are accumulating in the tissues, in the blood vessels, leading to plaque formation in the brain, leading to various kinds of under functioning of the brain tissue.
>
> **Jodelle Fitzwater:** So you've heard it here, folks. You don't need to take a fish oil pill. You can eat sugar and you want to make sure that you get rid of the ones they are calling the essential fatty acids like linoleic acid. Instead, you can eat a really awesome pro thyroid diet of things like cheese and milk and, um, good seafood and, um, you know, well cooked vegetables occasionally and getting some good starches from your fruits. Yes, Dr. Peat.

### Source 8 — Linoleic acid (an omega-6 PUFA) confirmed as direct driver of many (all?) cancers

Georgi Dinkov · Article · Apr 18, 2025 · https://haidut.me/?p=2768

> It looks like medicine is finally starting to wake up to the fact that PUFA is anything but benign, let alone beneficial. For decades. the main rationale for recommending PUFA intake has been their ability lower serum cholesterol. However, multiple studies have shown that lower cholesterol is NOT a good predictor of whether somebody develops and/or dies from heart disease (CVD). In addition, multiple studies have shown that lower cholesterol is a very good predictor, often decades in advance, of developing cancer. More specifically, the studies found that a deliberately lowered cholesterol through the intake of statins is linked to higher cancer risk in the future. It seems plausible to extend the same connection to PUFA intake as well, as it is often marketed by the food and medical industry as a “dietary” or “natural” statin.
>
> [references]
>
> Now, the study below has identified at least one mechanism through which the dominant dietary member of the PUFA family known as linoleic acid (LA) directly promotes growth and metastasis of the dreaded triple-negative breast cancer – a type of tumor that is highly aggressive, resistant to most types of treatment, and with a very poor prognosis. Apparently, LA promotes tumor growth by binding to and activating an enzyme called FABP5, which helps cells uptake PUFA from the bloodstream. While that enzyme can bind several fatty acids, its highest affinity is apparently for PUFA, and especially LA. In addition, expression of FABP5 has been found to be elevated in many other cancers, and its levels are highly correlated with poor prognosis. As such, PUFA is now directly implicated in driving the progression of many cancers. As the study itself states, LA consumption has skyrocketed since the 1950s, closely matching the increase in CVD and cancer rates, thus further corroborating its role as a dietary “pathogen”. While the study is, unsurprisingly, shying away from claiming that PUFA/LA can also cause cancer de-novo, the officially acknowledge role of PUFA (and LA specifically) as the main driver of inflammation (being a precursor of the prostaglandins and leukotrienes) leaves little doubt that LA is a true carcinogen, as chronic inflammation is now recognized as the main causal factor for developing any cancer (as well as virtually all chronic diseases). So, IMO it would not be unreasonable to change the title of the article to say that “PUFA is a major cause and driver of virtually all cancers”.
>
> [references]

### Source 9 — How the Wrong Dietary Fat Can Wreck Your Health - Discussion Between Georgi Dinkov & Dr. Mercola

Georgi Dinkov · Interview · Dec 18, 2022 · https://www.youtube.com/watch?v=icfBXeQSsq8

> **Georgi Dinkov:** but you know if you look at the actual research and what little lake acid that little lake acid does at the biochemical level it's very hard to come to a very different conclusion which is that it's a highly pro-inflammatory mediator which it has even without getting metabolized into inflammatory mediators it has its own endocrine effects which mimic largely those of estrogen And now estrogen is starting to get recognized as this big factor in disease. In fact, in 2001, National Institutes of Health declared estrogen, at least the ethanol estradiol, which is used in birth control pills, it declared as a known human carcinogen. Well, if we have this dietary component, which is virtually ubiquitous, it's everywhere, right? There's hardly a processed food anywhere where it does not contain at least one of the omega-6 fatty acids, mostly linoleic acid because it's so prevalent in nature. Well, if it's everywhere, then basically we're kind of getting into this hyper-estrogenic state, both males and females and children. And it's a little surprise that the rate of chronic disease has been rising. In fact, you can look at the curve of chronic disease, especially cardiovascular disease over the 20th century, and then overlay that another curve, which is the consumption of omega-6 fatty acids. And these curves match almost perfectly.

### Source 10 — Dogmatism in Science (Politics & Science, 2008)

Ray Peat · Interview · Jul 24, 2008

> **Ray Peat:** Well, the first claim was that it was linoleic acid then maybe linolenic was added, but already after the Burrs’ studies of the late 20s and early 30s – by the 1940s, they had a rare disease that was shown to be nothing but a vitamin B6 deficiency. At just about the same time, the agricultural researchers were showing that linolenic and linoleic acid were the causes of brain degeneration, testicular degeneration, and infertility, and muscle degeneration. And fish oils, around the same time were causing mink degenerative diseases. And then the yellow fat disease was showing up in more and more animals as they were fed fish waste, because of an excess of the polyunsaturated fat and the fish fat. So the linoleic acid finally was recognized to be essential for cancer, but not at all essential for nutrition. The publicity coming out that the original essential fatty acids were essential for cancer kind of discouraged the marketing in that direction, and that’s when it shifted to marketing fish oil, as the new version of the essential fatty acids. And that’s where we are now, at the, pretty much the peak of the fish oil promotion, because the new fatty acids that are being recommended, at higher intake levels to actually function as drugs to supposedly cure a lot of diseases, but in fact the old research going back 40, 50 years shows that it is simply a temporary suppression of inflammatory symptoms while in the long run increasing the inflammatory, degenerative processes.

### Source 11 — America’s favorite oil causes diabetes, obesity, autism, and liver / brain disease

Georgi Dinkov · Article · Jan 19, 2020 · https://haidut.me/?p=853

> A series of shockingly direct studies that do not shy away from pointing the finger at the real villain in modern public health history – PUFA, and more specifically the “essential” linoleic acid (LA). As the studies demonstrate, soy oil has strikingly detrimental effects on metabolic health and the main culprit, at least as far as diabetes goes, is precisely LA. Considering it is LA that is apparently responsible for the dramatic detrimental effects of soy oil, I see no reason why the studies’ findings cannot be extended to ALL vegetable oils containing significant portions of omega-6 PUFA such as LA. Now, if this was not enough, the same group published another study in 2017 demonstrating that omega-3 and its metabolites are also causative factors for diabetes. The findings on omega-3 were “surprising” to the researchers, because while medicine has slowly started to recognize the toxicities of omega-6, when challenged about health effects of PUFA the default defense tactic of medicine is to always claim that while omega-6 may indeed be pathological the omega-3 are not. As such, the doctors claim, the skyrocketing rates of CVD, diabetes, neurological disorders, cancer, etc are due to insufficient consumption of omega-3. You see, according to the doctors, all of our health problems would magically disappear if we simply increased the dietary ratio of omega-3/omega-6. Of course, they conveniently neglect to mention the multitude of studies demonstrating the role of omega-3 in lethal cancers such as melanoma, metastatic prostate cancer, glioblastoma, lung cancer, etc. I suspect that in another 10-15 years the evidence will finally be considered sufficient for medicine to reverse its genocidal dietary recommendations. Unfortunately, the price for that delay will be another 5-10 million lives lost to cancers caused by PUFA.
>
> However, this is not all. The same group that exposed the pathological effects of soy oil and linoleic acid did additional experiments and compared soy oil to corn oil, olive oil, coconut oil, and high fructose diet. Regular soy oil and corn oil reliably caused diabetes, as expected. A genetically engineered variety of soy oil called Plenish, which has almost no linoleic acid but a lot of oleic acid did not cause diabetes but was strikingly effective in causing fatty liver disease.

_Generated 2026-07-20 from the Bioenergetic Oracle corpus._