KUALA LUMPUR: The formulation of public health policies have, for generations, been misled by controversial theories that saturated fats are harmful, said Institute of Clinical Research founder and French cardiothoracic surgeon Dr Guy-André Pelouze.
He said dietary guidelines produced by experts and governments have been largely based on the work of American scientist Dr Ancel Keys in the 1950s, whose mistake has been compounded over the decades.
Keys’ study have become a fundamental topic in the debate around saturated fats as it claims to demonstrate a link between fat consumption with atheroma, an accumulation of fatty deposits in the inner layer of the artery walls that causes atherosclerosis.
“The controversy that saturated fats are uniquely harmful remains strong today as the debate on the role of smoking and sugar intake in relation to cardiovascular disease (CVD) associated with atheroma goes on.”
Keys described a link in the study cohorts between the percentage of saturated fats in the diet and the death rate caused by coronary events.
The correlation was dependent on the number of countries studied, but it was significant in the cohorts he chose.
“Since there is a correlation between total blood cholesterol and the same events, and since Keys highlighted that saturated fats (especially palmitic acid as it is the most common) could increase blood cholesterol level, a conclusion appeared,” said Dr Pelouze.
Keys stated that consuming saturated fats, including palmitic acid, was linked to coronary atheroma. Others then bridged the gap, saying it caused other coronary diseases as well.
Keys could not be held responsible for how his data was used, but his vision had overstated the negative effects of saturated fats and cholesterol in the risk of developing CVD.
“Obviously, all of them were not true. Inaccuracies and bias made his observations invalid,” said Dr Pelouze.
As a result, the cardiothoracic surgeon said populations have massively switched their diets to those that contain more carbohydrates.
The food industry has also turned to unsaturated vegetable oils that are rich in Omega-3 and Omega-6 fatty acids to reduce the amount of saturated fat in their products.
“But this did not change the prevalence of atheroma-related diseases. New research even shows these changes may be linked to the obesity epidemic and type 2 diabetes.”
He said palm oil, which has a good balance of saturated and unsaturated fats, constitutes a healthy alternative but it has been unjustly maligned as containing more saturated fat.
The inaccurate hypothesis against saturated fats by Keys also entails economic consequences that are felt today. Dr Pelouze said these are linked to the ability of the industry to quickly find a new marketing opportunity for low-fat food products.
“The industry has, as always, shown to be very innovative in that regard. Its lobby is powerful and ‘low-fat’ food gained a following globally, even though it is not possible to show that it has any positive impact on cardiovascular health.
“In the past 60 years between Keys’ work and the shadow cast by it, many scientific articles have been published to try and explain the anomalies observed in real populations.
“But none had ever questioned what has become a dogma,” said Dr Pelouze.
He said the only concession made in Keys’ theories is the confirmation of a strong influence of the composition of lipids in diet, but the words “saturated fats” are no longer used.
“We need to keep in mind that tobacco, type 2 diabetes and hypertension are, in that order, more powerful risk factors in causing atheroma than low-density lipoprotein (LDL) particles. There is no interest in controlling dietary cholesterol to prevent CVD.
“Saturated fats, like monounsaturated fats, may increase the amount of LDL particles when consumed in excess and promotes atheroma if other risk factors are present, and if the phenotype is susceptible.
“This is the reason why we cannot predict which patient with high LDL levels who will have a cardiovascular, cerebral or peripheral event other than monitoring the three aforementioned powerful risk factors, or by conducting atheroma plaque exams.”
Today, in reality, Dr Palouze said tobacco, diabetes and hypertension are much more powerful risk factors that lead to severe CVD.
“We condemn the researchers who, for more than 60 years, have not been keen to verify the data and the conclusions it suggested,” he said.