On a healthy, seed oil-free diet there is no “bad” cholesterol. But when your diet is full of seed oils, LDL becomes a problem.
The Heart Healthy Oil That’s Anything But
You may have noticed a pretty, red, heart-healthy label on certain vegetable oils. What you may not have noticed is an asterisk under the claim that says words to the effect of there’s only preliminary and limited evidence to support this statement. That snippet of legalese has quite a history behind it.
In the 1950s, margarine and cooking oil advertisers promoted their products as healthy due to the known cholesterol-lowering effect of polyunsaturates — the main fatty acid in seed oils. A string of prominent doctors objected to these tactics, since there was no evidence whatsoever to support the claim. Decades of wrangling finally resulted in a law prohibiting the promotion of margarine “or any other food, fat, or food oil” as a way of preventing disease unless it was grounded in science. A happy example of the Federal Trade Commission protecting the public that was over and done with back in 1974.
Which leads to my next point: we are here, nearly 50 years later, with no further evidence to support the heart-healthy claim than with what we had back then. Yet, the idea that lowering cholesterol prevents heart disease is still planted into our minds and remains the foundation upon which all of preventative cardiology rests. If your LDL cholesterol, the so-called “bad” cholesterol, is “too high,” your doctor will put the fear of death into you until you lower it.
To be clear, the polyunsaturates in seed oils do successfully lower total and LDL cholesterol. This is supported by a great deal of evidence, and nobody debates this. What’s more, as the dairy and other saturated-fat, rich animal fats in our food supply have been increasingly replaced by seed oils, our cholesterol levels as a country have dropped across the board. The average American’s total cholesterol is about 20 points lower today than in the mid-1960s, when we first started tracking. This drop is attributable to diet change, not drugs. So it’s absolutely true that swapping saturated fat for polyunsaturated fat lowers cholesterol levels. Now, here’s a question for you: so what?
The end goal of these dietary recommendations is not to lower cholesterol — it’s to help you live longer. Dying with lower cholesterol levels, what one of my patients termed “a Harvard death,” is not the goal.
Keep Your Eye On The Ball
Although seed oils do lower cholesterol, they do not keep you alive. At least we don’t have any evidence yet to support that idea — after 70 years of looking for it. We do, however, have evidence that foods fried in these oils contain “extremely high levels” of toxins known to cause cancer and neurodegenerative disease. Rather shockingly, a 2016 NIH study showed that for every 30 points these oils cut cholesterol, “there was a 22% higher risk of death.” It’s difficult to know, however, what exactly the people in the study died from, as 146 of the original 295 autopsy files were lost.
What’s clouding the issue is the fact that we are dying less often from heart attacks today than we were back in 1961, when heart attack deaths peaked. But it would be incorrect to assume that the drop in heart attacks means these cholesterol-lowering oils are heart healthy — or, for that matter, that the decline had anything to do with our lower cholesterol. The biggest factor behind the 50% drop in heart attack death rates is the fact that we’re smoking less.— much less. In 1961, both heart attack deaths and smoking peaked at their all-time highest levels. The average American (including children, smokers, and nonsmokers) smoked 4,000 cigarettes that year. By 2010, the per capita rate of smoking had fallen to 1,000, and heart attacks reached their lowest point. Since then, smoking rates continue to fall, while heart attack deaths are leveling out and appear to be climbing again.
I’d like to share a striking, though narrowly appreciated, secret: Harvard — the primary advocate for seed oils — has yet to nail down exactly how the polyunsaturated fats in these oils lower cholesterol. They don’t seem to care. Reviewing the medical literature reveals that, over the past 60 years, only two articles, found in The Journal of Clinical Endocrinology & Metabolism and The American Journal of Clinical Nutrition, discuss the subject — both hypothetical.
Why should you care what Harvard’s nutrition leadership knows about seed oils?
Harvard is the biggest advocate of the cholesterol theory of heart disease, and thanks to the university, all of preventative cardiology rests on the idea that lowering cholesterol is beneficial. Harvard works with the American Heart Association (AHA) to shape the U.S. government dietary policy regarding fat. Our K-12 state-funded college education systems, nursing homes, prisons, hospitals, and all other government-funded organizations are required by law to feed us more polyunsaturates than saturates — all because they lower cholesterol. Yet, if you ask the average cardiologist how polyunsaturates lower cholesterol, or how they know this effect is beneficial, I doubt you’ll receive a good answer.
The Cholesterol Hypothesis Needs To Go
It’s high time cardiologists clue in, though. Because after decades of reductions in deadly heart attacks, since 2010, they’ve started to creep upwards again. The combined effects of cholesterol-lowering drugs, further cuts in smoking rates, and advanced emergency care and cardiac surgeries are collectively failing to stem the tide of deadly heart attacks. It’s not just due to the population aging, since the mortality rates for people 65 and older actually went down between 2010-2019. There’s something very powerful driving this newly apparent trend.
Don’t look to the AHA for answers. It’s in its best interest that our notice in this recent increase in heart disease deaths is diminished. For 70 years, the cholesterol theory of heart disease has buttered its bread, so to speak. It literally can’t afford to change. For now, it’s much easier for it to cover up its mistakes by, for example, re-allocating deaths from the heart attack column to a different column, like hypertension, kidney disease, and more recently COVID. These and other efforts have prevented many doctors from noticing that eating seed oils and lowering cholesterol is failing to prevent heart attacks. But, mark my words: as long as we keep eating polyunsaturated-rich seed oils, death rates in younger generations will continue to rise. Sooner or later this egregious trend will garner the attention it is due.
Thankfully, the cholesterol theory is not the only theory in town. There’s another theory to explain the genesis of heart attacks that’s quietly gaining momentum — in spite of being mostly relegated to technical journals that doctors don’t read. This theory connects all the dots, explaining how cigarette smoking causes heart disease — something the cholesterol theory cannot do — while also explaining why drugs that drop your LDL number down to the lowest possible level only work to prevent a second heart attack about 30% of the time. That 70% failure rate is pretty grim, given the many side effects you expose yourself to when you’re taking these drugs and the fact that you will be taking them for the rest of your life.
Oxidation: What Cigarettes And Seed Oil Both Have In Common
Seed oils and cigarette smoking cause heart attacks for similar reasons. Whether you smoke, or you eat foods cooked in seed oils, the same set of toxins may enter your arteries. These toxins cause oxidation. So this theory is called, logically enough, The Oxidation Theory of Atherosclerosis. The oxidation takes place inside tiny fat-transport vehicles called lipoproteins. According to the theory, oxidation turns your lipoproteins from agents of nutrient delivery to agents of inflammation and disease.
What is oxidation, exactly? Technically, it’s the chemical reaction between oxygen and a fuel. The more familiar term is simply burning.
The oxidation theory explains that toxins from smoking and from cooking with polyunsaturated fats burn (oxidize) the interior of these tiny-fat transport vehicles. Seed oils play a dual role in the burning process, serving as both spark and fuel. That’s why the more polyunsaturated fat the vehicles carry, the faster the burning progresses. The transport vehicles include low density lipoprotein, or LDL (the so-called bad cholesterol), and high density lipoprotein, or HDL (the so-called good cholesterol), and a few others. These particles have slightly different functions in the body and normally they all do good stuff.
The oxidation theory tells us that lowering LDL may not be important at all, certainly not as important as preventing oxidation of LDL. So what do you do if you are one of the 40% of American adults with high cholesterol? Should you just take a statin?
That’s the topic of next week’s article.
Dr. Cate Shanahan is a board-certified Family Physician whose revolutionary approach to nutrition targets the underlying problems causing metabolic damage and inflammation. She is the NY Times bestselling author of The FatBurn Fix, Deep Nutrition and Food Rules. Her work has been featured in Sports Illustrated, Men’s Journal, and Prevention Magazine among others and she’s been a guest on Real Time with Bill Maher and The Megyn Kelly Show. Follow her at @DrCateShanahan
The views expressed in this piece are those of the author and do not necessarily represent those of The Daily Wire.