PUFAs Have Been and Always Shall Be Your Enemy
If you’ve been reading the news, you probably know that eating delicious foods like butter and eggs is no longer thought to increase risk of heart attack or stroke. This post discusses new information has come to light suggesting Ancel Keys suppressed evidence that polyunsaturated fats (PUFAs) are more harmful than trans fat!
For those of you who aren’t fully convinced that butter and eggs are healthy, I’ve devoted the first half of this article to highlighting why, when your doctor recommends that you swap out saturated fats in foods like butter and eggs for polyunsaturated fat in products like Smart Balance and packaged breakfast cereals, it’s largely thanks to Ancel Keys and his misleading, even dishonest, public statements.
Back in the 1950s and 1960s, Ancel Keys designed a series of highly influential experiments that changed the course of American dietary history. Before Keys, Americans enjoyed traditional foods like butter, eggs, and bacon without worrying about their health. After Keys made the cover of Time magazine on Jan 13, 1961, the American public was introduced to the idea that saturated fats were clogging their arteries, and that idea ultimately led to a sea change in the foods we eat. Real foods would increasingly replaced by processed, and the era of obesity and chronic disease would begin.
Keys’ First Tactic was to Blind Doctors With Science
In the Time magazine article Keys is paraphrased as stating “Americans eat too much fat. With meat, milk, butter and ice cream, the calorie-heavy U.S. diet is 40% fat, and most of that is saturated fat—the insidious kind…that increases blood cholesterol, damages arteries, and leads to coronary disease.”
Keys based his claim that saturated fat increases blood cholesterol on the experiments he’d done. But the experiments were not performed using real foods rich in saturated fat. His experiments used saturated fats that had been artificially created from vegetable oils using a process called hydrogenation. Hydrogenated vegetable oils contain not just saturated fat but also trans fat and a whole host of other unnatural molecules. Trans fat does indeed raise blood cholesterol, as well as lead to heart attacks and strokes, and has been since shown to be so unhealthy cities like Manhattan and San Francisco have outlawed its use in restaurants.
Keys wasn’t trying particularly hard to hide this deception. One publication he authored was titled “Hydrogenated fats in the diet and lipids in the serum of man,” which should have been a red flag that he was not using real food in his experiments. But it wasn’t. Although doctors do learn some biochemistry, it’s not enough, and what little we do learn is not put in the context required to become relevant. Bottom line is I didn’t learn what hydrogenated fats were in medical school, and the doctors of Keys’ day would have had no idea either. So when Keys said saturated fat from butter and eggs caused atherosclerosis, he was intentionally misleading everyone by implying that he was speaking of the results of his experiments, when he was not.
This is how Keys managed to pull the wool over the eyes of generations of doctors–because he understood chemistry better than they did.
Recently, thanks to authors of blockbuster books like Good Calories, Bad Calories, The Big Fat Surprise, and The Primal Blueprint, the reading public has come a long way in our understanding of the health harms of trans fat, and the lack of harm from natural saturated fat. This information has trickled down to influence the thinking of some doctors as well, and a few have lifted their restriction on butter and eggs.
But Keys did more than fool physicians into believing eating butter and eggs would kill us.
Keys also convinced doctors that eating polyunsaturated fats would help people live longer.
In spite of progress in the realm of saturated fat, doctors still have a long way to go in understanding the health consequences of consuming polyunsaturated fats from industrially produced vegetable oils. Nutrition science as a whole has made very little progress on this front in large part because Ancel Keys appears to have done everything in his power to keep us from understanding just how unhealthy polyunsaturated fats and vegetable oils can be.
Medical detective work by Christopher E. Ramsden, medical investigator at the NIH, who published an article called “Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73)” implicates Keys in a scientific cover up, perhaps the biggest cover up of important health data ever committed in American history.
The Minnesota Coronary Experiment was a massive undertaking involving thousands of adult residents of six state mental hospitals and one nursing home. The study subjects were divided into two experimental groups and fed two different experimental diets for between 3 1/2 and 4 1/2 years, depending on the hospital. One experimental diet was high in saturated fat, the other high in polyunsaturated fat. The high saturated-fat diet contained lots of margarine and shortening, both loaded with trans fat, and not much if any butter or natural animal fats (some of the details are lost to history). The diet high polyunsaturated-fat diet contained lean meats and skim milks and cheeses to which corn or other vegetable oils were added, along with some margarines, and no butter or natural animal fats.
The Minnesota Coronary Experiment was composed of two parts, each designed to test the validity of a different hypotheses:
1) That a diet high in polyunsaturated fat would lower cholesterol.
2) That a diet high in polyunsaturated fat would reduce atherosclerosis and deaths from heart attack and stroke.
The first hypothesis turned out to be true. Sort of.
Part One of Keys’ Study:
Polyunsaturated Fats do Lower Cholesterol…
After one year, the study subjects were retested and those in the polyunsaturated fat diet group had cholesterol levels 30 points lower, on average, than those in the saturated fat group. And that’s the reason doctors still to this day recommend increasing your intake. But remember, this reduced blood cholesterol from polyunsaturated fat is not compared to actual foods containing saturated fat. It’s compared to artificially made saturated fats from hydrogenated vegetable oils, and that means they would also contain massive amounts of trans fat.
…But Keys Only Compared Polyunsaturated Fats to Trans Fats
Trans fats have been shown to raise cholesterol. And foods containing artificially made saturated fat, like margarine and shortenings, contain lots of trans fat. These foods have been clearly shown to elevate cholesterol when added to a diet that was previously free of these foods.
But Keys studies never included a diet composed of actual foods rich in saturated fat.
When compared to actual food, the difference is slight and inconsistent.
Years later, others compared butter to both margarine and polyunsaturated fat, and found that polyunsaturated fat did indeed reduce cholesterol compared to butter–but not by much.
Taken together, Keys’ research plus the research showing slight differences between butter and polyunsaturated fat was enough to convince doctors that polyunsaturated fats do indeed produce reductions in serum cholesterol. That’s why products like Smart Balance can claim to reduce your cholesterol, and it’s why thousands of other products claim to be heart healthy.
But are they?
Part Two of Keys’ Study:
The second part of the experiment, the results that Keys suppressed and that Dr. Ramsden published, showed that the study group that got more polyunsaturated fats were not only not protected from heart attacks and strokes by the diet, but appeared to be at slightly increased risk for both.
The graphs below show the results of statistical analysis of various subgroups. The blue lines (labeled Diet) represent the diet high in polyunsaturated fats, and the red line (labeled control) represents the diet high in saturated and trans fat from margarines and shortenings. The higher the line, the more deaths. What we see is that the blue line is higher than the red line in all the groups no matter how you divide up the study participants (but especially in women over the age of 65), and that means the diet high in polyunsaturated fat caused more deaths than the diet high in saturated fats.
This is huge.
Polyunsaturated Fats INCREASE the Risk of Heart Attack and Stroke
We know that Keys’ so-called saturated fat diet was also loaded with trans fats, and we know that trans fats cause atherosclerosis. The Nurses Health Study showed that for each 2% increase in trans fat in the diet, the risk of heart disease is doubled. And if this trans-fat loaded diet performed BETTER than a diet high in polyunsaturated fats, that suggests polyunsaturated fats from processed vegetable oils, when consumed in the amounts consumed in the study, are more unhealthy than trans fat.
The medical investigator and study’s lead author was not able to quantify exactly the amount of trans fat in the saturated (here labeled “control”) diet, but it was likely to be quite a lot higher than the amount of trans fat in the polyunsaturated (here labeled “diet”) diet.
The amount of polyunsaturated fats in this experimental diet was not provided. Instead, the authors provide the amount of a single type of polyunsaturated fat that is also the most common of all polyunsaturated fats in vegetable oils, called linoleic acid. The study diets contained between 8 and 12% of calories from linoleic acid. Today’s average American consumes about 10 % of calories from linoleic acid, which puts us right in the ballpark of the average study participant. In other words, the average American is on a diet very much like Keys’ high polyunsaturated fat diet that does lower cholesterol but actually increases a persons risk of heart attack and strokes compared to a diet high in trans fat.
In other words, the American public is trapped in Keys’ medical experiment.
And we know what the results will be: more heart attacks and strokes. American doctors who still recommend polyunsaturated fats are unknowingly putting their patients at risk of death or disability. This is why every doctor should learn the truth about Ancel Keys’ experiments.
Unfortunately, when faced with potential reason to change our practice behavior, most doctors behave like herd animals in that we instinctively follow the recommendation of authorities in order to avoid slaughter by predatory lawyers.
And our authorities show no sign of changing their direction, in spite of this additional body of evidence that Keys’ did not have best intentions at heart.
Harvard’s Nutrition Department Chair, perhaps the ultimate authority figure on the topic of diet and health, still celebrates Keys’ legacy, and continues to promote polyunsaturates. In an interview response to the publication of Dr. Ramsden’s article, the department chair and co-author with Keys on numerous articles, Dr. Walter Willet, expressed his disregard for the potential value of these newly released findings: “This is an interesting historical footnote that has no relevance to current dietary recommendations.”
Hopefully, Dr. Willet will retire and be replaced with someone less invested in the status quo.
There’s one more twist to this story. A twist that gets to the core of what’s wrong with the idea that cholesterol causes heart attacks. And if you have been wondering, how does a diet that reduces cholesterol increase heart attacks and strokes, you are already thinking in the right direction.
The reason they lower cholesterol has not been systematically examined. What little evidence we do have suggests they reduce cholesterol by causing a fatty streak, the first stage of atherosclerosis, and I review that evidence in this video. It has to do with disruptions in the function of lipoprotein, and I go into more detail in Chapter 7 of Deep Nutrition (Chapter 8 in the original version), entitled Good Fats and Bad.
Related Content on DrCate.com :
Related content from the web:
A 2014 article defending Keys reputation that was, at the time, being publicly called to question because of how he covered up data in his famous 7-countries study. This was before the 2016 article came out implicating Keys in an entirely different cover up.
The 7-countries study controversy, covered by Authority Nutrition with a cute video.
A brief movie about Keys. At minute 22 we gain some insights into how Keys public humiliation at a scientific meeting in 1955 may have lead to his obsession with proving fat intake was the problem. Rather than being driven to find the truth, he was driven by a desire to redeem his idea, “I’ll show those guys.”
Harvard’s rebuttal of Dr. Ramsden’s study by Dr. Willet, who defends the status-quo and blames the increased deaths in the polyunsaturated arm of the study on the lack of supplemental omega-3. This suggestion seems absurd, since the polyunsaturated corn oil would have contained more omega-3 than the hydrogenated oil diet that outperformed it. He also states the study was not long enough. It was, in reality, one of the longest if not the longest study to date.