{"id":29025,"date":"2025-10-11T06:00:03","date_gmt":"2025-10-11T04:00:03","guid":{"rendered":"https:\/\/cristinatomasi.com\/?p=29025"},"modified":"2026-01-07T10:51:52","modified_gmt":"2026-01-07T09:51:52","slug":"the-myth-of-cholesterol-part-two","status":"publish","type":"post","link":"https:\/\/cristinatomasi.com\/en\/il-mito-del-colesterolo-seconda-parte\/","title":{"rendered":"The cholesterol myth - part two"},"content":{"rendered":"
by Oliver Ruatti<\/strong><\/h6>\n

The origins of the myth about fat and the heart<\/b><\/h1>\n

When did the war on fat start? To cholesterol?<\/b><\/h2>\n

In the 1950s, an American physiologist, Ancel Keys<\/b>, forever changed the way the<\/p>\n

world thought of fats.<\/p>\n

His theory-that fats in the diet increased cholesterol in the blood and this<\/p>\n

caused heart disease-it became the basis of modern nutritional guidelines.<\/p>\n

But what was really behind this hypothesis? And how well-founded was it?<\/p>\n

 <\/p>\n

From rabbits to humans<\/b><\/h3>\n

Initially, studies on atherosclerosis were based on experiments conducted on the rabbits<\/b>,<\/p>\n

Herbivorous animals that easily developed arterial lesions when fed foods of<\/p>\n

animal origin. Keys and other researchers transposed these findings to humans, hypothesizing.<\/p>\n

that the dietary cholesterol<\/b> Was the culprit.<\/p>\n

However, as early as the early 1950s, the same human experiments showed.<\/p>\n

which increasing cholesterol in the diet did not change cholesterol levels in the<\/b><\/p>\n

blood<\/b>.<\/p>\n

Keys himself admitted this in 1954: \"The cholesterol content of the diet does not have an effect<\/i><\/p>\n

significant on either blood cholesterol levels or atherosclerosis in humans.\"<\/i><\/p>\n

 <\/p>\n

From blaming cholesterol to blaming fat<\/b><\/h2>\n

Having failed to make a direct association between dietary cholesterol and blood cholesterol, Keys changed<\/p>\n

target: he decided that the problem was no longer cholesterol, but the total fats<\/b>.<\/p>\n

In 1953 he presented a graph showing an apparent correlation between consumption of<\/b><\/p>\n

fats<\/b> is also mortality from heart disease<\/b> In six countries.<\/p>\n

\"\"
(The graph shows the correlation between deaths from heart disease and the percentage of<\/i>
calories derived from fat compared to total calories consumed. In a nutshell, the graph<\/i>
shows: more fat intake=more deaths from heart disease).<\/i><\/figcaption><\/figure>\n

 <\/p>\n

 <\/p>\n

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 <\/p>\n

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 <\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

But two epidemiologists, Yerushalmy and Hilleboe<\/b>, they noticed something strange:<\/p>\n

data were available for 22 countries<\/b>, not just six-and, including all of them, the correlation<\/b><\/p>\n

disappeared<\/b>.<\/p>\n

\"\"
(Graph almost identical to the one above. Difference: fat consumption is no longer correlated
With an increase in deaths from heart disease. For example: In Norway (17) there is a
much higher fat consumption than in Israel (11), but in Norway there are
However, far fewer deaths from heart disease. In Mexico (14) there is a consumption of
fat similar to that of Israel (11), but still in Israel the number of deaths from
heart disease is significantly higher. Ergo, it cannot be argued that there is a
causal correlation between fat consumption and deaths from heart disease. They need to be
other factors in play).<\/figcaption><\/figure>\n

 <\/p>\n

The logical fallacy<\/b><\/h3>\n

Yerushalmy and Hilleboe highlighted more errors:<\/p>\n

1. 2. 3. the definitions of \"heart disease\" were arbitrary,<\/p>\n

other nutrients (such as the animal protein<\/b>) showed even stronger correlations,<\/p>\n

and a greater share of carbohydrates<\/b> in the diet was associated with more mortality<\/p>\n

elevated for other causes.Their conclusion was clear: there was no evidence that fats caused the<\/b><\/p>\n

heart disease<\/b>.<\/p>\n

Rather, the consumption of animal fat and protein seemed to reflect the level of development<\/b><\/p>\n

cheap<\/b> of countries: richer nations ate more fat and lived longer,<\/p>\n

but they died more from chronic causes such as heart attack-not that fat was any<\/p>\n

the cause.<\/p>\n

In parallel with Yerushalmy and Hilleboe, the British physiologist also. John Yudkin<\/b> observed<\/p>\n

That heart disease seemed to be follow wellness, not fat<\/b>.<\/p>\n

Analyzing international data, Yudkin noted that countries with more income, more technology<\/b><\/p>\n

and more comfort<\/b> were also those with the higher coronary mortality<\/b>.<\/p>\n

He wrote with subtle irony:<\/p>\n

\"The strongest correlation I have found with coronary mortality is not with fat,<\/p>\n

But with the number of radio and television licenses.<\/p>\n

There is almost as good a correlation with the number of registered cars.\"<\/p>\n

Behind Yudkin's humor was a powerful message:<\/p>\n

heart disease could be A side effect of modern progress<\/b>,<\/p>\n

not butter or eggs.<\/p>\n

In other words, what Keys interpreted as a \"fat fault\" could actually<\/p>\n

reflect the price of development<\/b>- sedentariness, stress, urbanization, food<\/p>\n

industries and a radical change in lifestyle.<\/p>\n

The forgotten side: carbohydrates and mortality<\/b><\/p>\n

Yerushalmy and Hilleboe also deepened the relationship between fat, protein, and<\/b><\/p>\n

carbohydrates<\/b> and the causes of death other than heart disease<\/b>.<\/p>\n

The results were surprising:<\/p>\n

-<\/span> A higher percentage of calories from fat<\/b> was associated with fewer deaths from<\/b><\/p>\n

other causes<\/b> (r = -0,657).<\/p>\n

-<\/span> Also the animal protein<\/b> showed a negative relationship (r = -0.405).<\/p>\n

-<\/span> But the carbohydrates<\/b>? Here the correlation was positive and strong: r = +0,671<\/b>.<\/p>\n

In practice, The higher the percentage of calories from carbohydrates, the more<\/b><\/p>\n

increased mortality from causes other than heart disease.<\/b><\/p>\n

But even here it is merely correlation, not causation.<\/p>\n

-<\/span> Yerushalmy and Hilleboe in 1957 were not proving that. carbohydrates<\/b><\/p>\n

\"cause\" more deaths<\/b> For other diseases.<\/p>\n

-<\/span> They were simply showing that, in the available data at the level of<\/b><\/p>\n

populations<\/b>, there was a positive relationship<\/b> between percentage of calories from<\/b><\/p>\n

carbohydrates<\/b> is also non-coronary mortality<\/b>.This observation served to Questioning Keys' claim of certainty<\/b>, not to<\/p>\n

Reverse the blame.<\/p>\n

 <\/p>\n

When theory becomes dogma<\/b><\/h3>\n

Keys did not accept the criticism. In 1956 he launched the famous Seven Countries Study<\/b>,<\/p>\n

designed to prove his hypothesis.<\/p>\n

The results?<\/p>\n

-<\/span> No correlation between total fats<\/b> and heart disease.<\/p>\n

-<\/span> A correlation only with the saturated fats<\/b>, but without proof of causation.<\/p>\n

Nevertheless, the public narrative was consolidated: \"saturated fat is bad for the heart.\"<\/i><\/p>\n

And that belief, born of imperfect correlations and data selections, would drive<\/p>\n

decades of guidelines, demonizing natural foods such as butter, eggs and meat.<\/p>\n

 <\/p>\n

The lecture<\/b><\/h3>\n

The origins of the myth about fats remind us of a fundamental principle:<\/h3>\n

a correlation is not a cause.<\/p>\n

Keys never proved that saturated fat causes heart disease; yet his<\/p>\n

assumption, amplified by the media and institutions, has shaped modern nutrition more than<\/p>\n

any other theory.<\/p>\n

As physiologist George Mann observed in the 1970s, \"The diet-heart hypothesis is the most<\/p>\n

great scientific deception of our time.\"<\/p>\n

 <\/p>\n

MORAL:<\/b><\/h3>\n

The science of nutrition is not static. Many of the dogmas we take today for<\/strong><\/p>\n

discounted arise from methodological errors and hasty generalizations. Understanding the history of the<\/strong><\/p>\n

fat also means learning to question what we think we know.<\/strong><\/p>\n

 <\/p>\n

As always, I invite you to debate and discussion.
\nI look forward to seeing you in the comments...<\/p>\n

 <\/p>\n

See you soon and have a great weekend!<\/p>\n

Oliver Ruatti<\/strong><\/p>","protected":false},"excerpt":{"rendered":"

di Oliver Ruatti Le origini del mito sui grassi e il cuore Quando \u00e8 iniziata la guerra ai grassi? Al colesterolo? Negli anni \u201950, un fisiologo americano, Ancel Keys, cambi\u00f2 per sempre il modo in cui il mondo pensava ai grassi. La sua teoria \u2014 che i grassi nella dieta aumentassero il colesterolo nel sangue […]<\/p>\n","protected":false},"author":7,"featured_media":29033,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[110,106,178,1],"tags":[],"class_list":["post-29025","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-grassi-buoni-o-cattivi-e-colesterolo","category-alimentazione","category-benessere","category-non-categorizzato"],"_links":{"self":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts\/29025","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/comments?post=29025"}],"version-history":[{"count":0,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts\/29025\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/media\/29033"}],"wp:attachment":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/media?parent=29025"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/categories?post=29025"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/tags?post=29025"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}