In the 1950’s Ancel Keys developed the “Diet Heart Hypothesis”. He suggested that eating saturated fat increased blood cholesterol and in turn caused heart disease. In 1958 he published The 7 Countries Study showing data that demonstrated a correlation between saturated fat and heart disease deaths. However, what he didn’t disclose was that there were actually 22 countries in total that were part of that study. Keys deliberately dismissed the other 15 countries and refused to include any countries where he already knew the populations of those countries ate large amounts of saturated fats and had low rates of heart disease. When the data from the other 15 countries were analysed it was clear that there were many countries who didn’t consume a lot of saturated fat that also had a high amount of heart attacks and also countries who ate a considerable amount of saturated fat who had lower rates of heart attacks which completely disproved his theory.
This observational study did not look at the full picture, it showed correlation in just 7 of these countries, not causation, but it did show the bias of Keys. Despite this study being biased it went on to significantly influence government health guidelines around the world and we still follow those guidelines today, even though his theory has been picked apart and debunked many times by experts with considerable more expertise than Keys. The American Heart Association at the time played a huge role in spreading the biased results of Key’s study and it just so happened to have received a $1.7 million donation which enabled its launch from Proctor and Gamble, makers of the first seed oil product, Crisco, a polyunsaturated fat promoted as “heart healthy”.
The way we are advised to eat today is still based on this flawed study and could be the most detrimental advice to human health in history. Despite all the overwhelming scientific evidence against it you have to ask why the guidelines have still not been changed?
