A Biased Study & A Bribe… the story of why saturated fat got unfairly blamed for heart disease.

The biased study... In the early 1950’s a physiologist called Ancel Keys developed what he called the diet-heart hypothesis. 

This stated that saturated fat consumption increased blood cholesterol, which in turn led to heart disease. 

In 1958 Keys published the 7 Countries Study.

The data in the study (below) showed that Keys may well be right. It demonstrated an obvious correlation between the percent of dietary calories from fat and heart disease deaths. 

However the reality was that Keys looked at 22 countries as part of the study (full data set below). 

When you look at the full picture, it’s clear that there’s some countries that don’t consume a lot of fat, which have high amounts of heart attacks and vice versa. 

This not only disproves his hypothesis but it shows why you can’t take studies at face value. 

Don’t get me wrong, there’s plenty of really good research out there, which provides amazing insights. 

However, as in this case, lots of studies are biased because of the researchers predisposition or they’re being funded by a company that has a vested interest in an outcome. 

Also observational studies, like this one, don’t look at the full picture. Just because there’s correlation, doesn’t mean there’s causation. 

For example, the US fitted Keys hypothesis well. However the study didn’t look at processed food, alcohol, cigarette, etc consumption.

The reality is these deaths were likely caused by a combination of unhealthful behaviours. 

Whenever I see something like this, I find that looking through the lens of evolutionary biology can quickly help you work out whether it’s accurate or not. 

Is saturated fat something we would have consumed for the vast majority of human history? Yes - animal fat has been a staple of our diet for 99.9% of existence. Then our biology is designed to consume it and it's unlikely to be causing issues. 

Despite this study being biased, it went on to massively influence health guidelines (and it still does today) world wide. 

The ‘results’ of Key’s study suggesting that saturated fat causes heart disease, although obviously extremely flawed and biased, started being disseminated by the newly formed American Heart Association (AHA) in 1961.

However, the AHA had a major undisclosed conflict of interest; it had basically been launched by a $1.7 million donation (equivalent to $20m today) from Procter & Gamble, the maker of Crisco - the first vegetable / seed oil product (a polyunsaturated fat).

This donation transformed the AHA from a very small group into a national organisation.

Ever since they’ve promoted vegetable and seed oils as “heart healthy” and warned people away from saturated fat. This disinformation has gone on to influence government food policy worldwide and permeated into a huge number of public institutions, including; hospitals, schools, care homes, etc.

However, the reality of the situation is:

• Rigorous clinical trials testing this hypothesis have demonstrated that saturated fat does not cause heart disease.

• This newer science has been actively suppressed, suggesting longstanding biases in the field and the influence of vested interests.(Study)

Not only this, but vegetable and seed oils promote oxidative stress within the body, which has been linked to the rise in basically all the chronic diseases we see today.

For this reason and due to how many people it influenced, many consider the advice to swap saturated fat (butter, tallow, etc) for polyunsaturated vegetable / seed oils to be the most damaging piece of health guidance ever given.

Despite the best scientific evidence dispelling the myth that saturated fat causes heart disease, this message is still promoted by many official institutions including the AHA and NHS.

Do you think this is because of longstanding biases? Or is bribery still involved?