Ancel Keys – villain or hero?
ANCEL KEYS is regarded as somewhat of a villain within the anti-trans fats movement.
For it was he who, in the late 1950s, proposed the theory and “proved” that saturated fats cause heart disease and later, that saturated fats raise cholesterol levels.
His theory, often referred to as the lipids theory or diet-heart theory, has become so widely accepted that most people today take for granted that it is absolutely true.
It led to widespread fear of saturated fats, to the point where the many health benefits of saturated fats get totally ignored and forgotten. To most people today, doctors, nutritionists and lay people alike, saturated fats are bad, bad, bad.
This, in turn, led to the widespread acceptance of trans fats in products like margarine, vegetable shortening and partially hydrogenated vegetable oils.
It is only in recent years that a growing number of scientists and health authorities realise that trans fats are the real culprits in causing heart disease, and that saturated fats are, at worst, slightly harmful or, at best, highly beneficial.
Ancel Keys has become so widely associated with the saturated fats and cholesterol theory that he earned the nickname, Monsieur Cholesterol.
Margarine and cholesterol
Little known about Ancel Keys is the fact that, as long ago as 1956, he had already speculated that trans fats might be harmful to health and be the cause of heart disease.
That makes him one of the earliest, if not the earliest, scientists to sound a warning against trans fats. And his early recommendation for preventing heart disease was to cut down the intake of vegetable oils and margarines.
However, he later discovered that vegetable oils, which are mainly unsaturated fats, tended to lower blood cholesterol levels, while saturated fats tended to raise cholesterol.
By then, it was decided that saturated fats, by raising cholesterol, caused heart disease. The recommendation to reduce margarine intake became forgotten.
Ancel Keys suspected a link between fats and cholesterol when he examined a Wisconsin dairy farmer who was referred to him by the University of Wisconsin medical school. He recalled:
“He had big knobs on his and elbows and over his eyes, and when you opened them, it was just pure cholesterol inside. We checked this fellow’s serum cholesterol level, and the first reading was 1,000. His brother, who came with him, had a reading of 600.
“The average level in the United States is about 220 or 230, so of course this was sky high. So we put them over in the laboratory, fed them there for a week, and bang! Their cholesterol levels dropped down to 500 and 300. Essentially we put them on a fat-free diet. Wasn’t very tasty.
“Then we got thinking about the possibility of giving them some fat. We gave them some vegetable margarine and their cholesterol levels shot back up again.”
At the time, however, ideas about fats and cholesterol were new and not well understood. Ancel Keys at first did not even know that the fat in margarine was saturated fat. t was only some years later that he refined his theory and focused on saturated fats.
Thus, between 1953 and 1958, Ancel Keys made a number of inconsistent and contradictory statements about fats and their influence on health:
- All fats raise serum cholesterol
- Nearly half of total fat comes from vegetable fats and oils
- No difference between animal and vegetable fats in effect on coronary heart disease;
- Type of fat makes no difference
- Need to reduce margarine and shortening;
1957 – 1959:
- All fats are comparable
- Saturated fats raise and polyunsaturated fats lower serum cholesterol
- Hydrogenated vegetable fats are the problem
- Animal fats are the problem
Given the overall low level of knowledge and understanding at that time, Ancel Keys could not really be blamed for his inconsistencies.
Viewed more positively, it can even be said that he was quite open minded and had explored various possibilities. It was just unfortunate that the saturated fats theory got developed further while the idea that trans fats in hydrogenated oils might be the problem was not pursued.
Seven Countries Study
The most famous, and most often cited, work of Ancel Keys was the Seven Countries Study – a 20-year study of about 12,000 men between the ages of 40 and 59 from 16 communities in Italy, the Greek islands, Yugoslavia, the Netherlands, Finland, Japan and the United States.
The Seven Countries Study is said to “prove” that countries with the highest saturated fat consumption had the highest rates of heart disease.
Subsequent researchers had criticised this Seven Countries Study and pointed out serious flaws. But these criticisms were largely ignored and the theory that saturated fatss “cause” heart disease became widely accepted.
The Seven Countries in Ancel Keys study were said to have been chosen for their contrasting dietary patterns and the relative uniformity of their rural labouring populations.
However, a major criticism is that Ancel Keys had chosen to study only those countries where both saturated fats consumption and heart disease were high. He ignored other countries that ate similar diet but had low rates of heart disease.
The statistician Russell H. Smith had this to say about the Seven Countries Study:
“The dietary assessment
methodology was highly inconsistent across cohorts and thoroughly
suspect. In addition, careful examination of the death rates and
associations between diet and death rates reveal a massive set of
inconsistencies and contradictions. . .
It is almost inconceivable that the Seven Countries study was performed with such scientific abandon. It is also dumbfounding how the NHLBI/AHA alliance ignored such sloppiness in their many “rave reviews” of the study. . .
In summary, the diet-CHD
relationship reported for the Seven Countries study cannot be taken
seriously by the objective and critical scientist.”
– Diet, Blood Cholesterol and Coronary Heart Disease:|
A Critical Review of the Literature, Volume 2, November 1991
Not entirely to blame
It is not entirely fair to blame Ancel Keys for his lapses, since he lived and worked at a time when the general level of knowledge was low.
None of Ancel Keys’ that “proved” saturated fats to be harmful took trans fats into account. In fact, none of the many subsequent researchers who came to similar conclusions took trans fats into account.
The researchers were all studying people who ate both saturated fats and trans fats. They then blamed saturated fats for causing problems like heart disease when, in fact, trans fats were the actual cause.
It is only in more recent years that researchers – such as Mary Enig at Univrsity of Maryland and Walter Willet at the Harvard School of Public Health – considered saturated fats and trans fats separately and discovered that trans fats are the real culprits.
The real people to blame are today’s doctors, scientists and health authorities. Desspite having access to more – and more updated – information, they continue to cling tightly to the incomplete and faulty theories of Ancel Keys that were formulated 50 years ago.
The mainstream view
Outside of the anti-trans fat / pro-saturated fat movement, therefore, Ancel Keys is very much regarded as one of the greatest scientists of modern times. In 1961, he made it to the cover of Time Magazine.
And, when Ancel Keys died on 20 November 2004, just two months short of his 101st birthday, The Times of London wrote:
Ancel Keys… had a profound effect on society’s attitude to food and exercise. He introduced many of the assumptions which we now take for granted…
Anyone with such accomplishments would be
considered a truly great man. Except that in the case of Ancel Keys, his
ideas might have been somewhat mistaken.