Vilifying the Fat

I have mentioned several times in various post that vituperation of fat was based on bad science and flawed research data. In this post, we will see how and who is behind the reviling of Good (old) Saturated fat.

The vilifying the fat has a very long story. Though it began in 1913, it become aggressive in 1952 and become officially declared by US government in 1977. 

In 1913, a Russian pathologist called Nikolai Anitschkow wanted to study the effect of cholesterol and health. He decided to feed the purified cholesterol to the rabbits and managed to elevate their blood cholesterol levels up to 1,000 mg/dl (nearly 26 mmol/L) then noticed the formation of “vascular lesions” closely resembling those of human atherosclerosis, forming in the arteries of the rabbits. 

Nikolai Anitschkow

There are two obvious flaws in the experiment. The first one was the subject “Rabbits” and they are strict herbivores. They do not eat animal products (cholesterol only derives from animal sources) hence, they don’t produce bile acids to digest fat. Thus, their digestive system is not equipped to handle cholesterol.

It’s like fueling the diesel engine with petrol and blaming the petrol is not a fuel or petrol damaged the engine.

The second flaw was the Blood cholesterol level, it was around 1000mg/dl. Even after eating very high amount of saturated fat (3 times a day) for two years, I wasn't able to touch 300mg/dl. (refer my lipid profile here)  It’s practically impossible to elevate 1000mg/dl in humans. 

Interestingly, similar such (cholesterol feeding) studies was done on rats and dogs (omnivores) and feeding cholesterol to these species failed to produce vascular lesions.

The demonization of saturated fat began in 1952 when Dr. Ancel Keys created a mythology in his paper linking saturated fat intake and heart disease mortality (Popularly known as Seven Countries Study) of different countries and published the below graph to prove his preconceived result. (Based on Nikolai Anitschkow rabbits study)

From the above graph Ancel Keys, could easily prove his preconceived idea of fat by associating or correlating the fat consumption and CVD.  But, the truth was he had around 22 countries data and he cherry-picked the data according to his preconceived idea. Find below the data’s he originally had.

Ancel Key intentionally left the data’s from other 16 countries, in order to prove his theory. He did not choose his countries randomly but instead selected only those likely to prove his beliefs – including Yugoslavia, Finland and Italy – while excluding countries with low rates of heart disease despite diets with a lot of fat – such as France, Switzerland, Sweden and West Germany. Just draw an imaginary line linking all the 22 country you can’t find any correlation between Fat consumption vs CVD.

The above graph shows the original data, the “real” correlation and Ancel key’s intentional correlation. Also, due to difficulties in collecting accurate nutrition data, Keys ended up sampling the diets of fewer than 500 men, far from a statistically significant sample.

There are many studies available to prove there is no correlation between high cholesterol intake with heart disease. Find below an another study result. 

Ancel Keys aggressive, persuasion personality managed to implanted his idea into the American Heart Association, National Institutes of Health (The McGovern Committee) and first-ever guidelines calling for Americans to cut back on saturated fats, as the best way to fight heart disease. The US government adopted this view, officially in 1977. As usual, rest of the world (BLINDLY) followed. 

However, (less fat, high carb) food guidelines received major criticism at the time from many respected scientists like John Yudkin (who insisted that sugar was to blame) and the American Medical Association. (will write an separate post later about Dr. John Yudkin) but all in vain. 

Ancel Keys flawed study produced the ‘Lipid Hypothesis’ and gained massive media attention and Times magazine honored (!) him by publishing his photo as its cover page. Media around the world spread the lie (along with medical associations) among the common people.  Times magazine took 57 year to realize the mistake and finally removed the saturated fat (butter) in 2014 from the prohibited list, by the time huge damage to the mankind already took place.

The above graph (plotted from the statistical data by the obesity research in US) is the self-explanatory the effect of High Carb (less or No fat) diet. Ancel key used to prove his theory ONLY by correlating the Fat and CVD. Association or correlation alone need not to be a causation. Major problem in (especially medical) science is by finding / deriving an association or correlation between the two different variable leaving the other (influencing) factors.

It’s not (always) possible to conclude something only based on an association or correlation factor. Such conclusions may be possible and accurate in other field, where there is no “other” factors involved. Whereas, in physiology (biology) it’s not that easy because of many “other” factors can alter or affect the end result. Here, the very important “other” factors are carbohydrates and hormone's, which plays a major role, just not only the Fat.

   Association or Correlation is NOT (necessarily to be a) Causation.

Here is an example……..The blow graph shows the very close correlation between atmospheric CO2 level and obesity levels. Based on this, If one can conclude, that atmospheric CO2 is the root cause of Obesity. Will you be accepting?

Observational studies can only establish associations. They cannot say that “A” (fat) causes “B” (heart block).  Ancel key study also an Observational study. May be later will write more about such studies.