New study from Ateneo debunks relationship of saturated fat to heart disease

Maybe saturated fat and cholesterol aren't so bad after all — at least that's what the new study from Ateneo de Manila University professor and chemist Dr. Fabian Dayrit and American physician Mary Newport is saying.

The study, which is lengthily called “The Lipid-Heart Hypothesis and the Keys Equation Defined the Dietary Guidelines but Ignored the Impact of Trans-Fat and High Linoleic Acid Consumption,” looked at a 1953 study of physiologist Ancel Keys which said high contents of saturated fat and cholesterol in the diet raise cholesterol levels in the blood and contribute to heart disease.

Keys' study also said you can lower your total cholesterol and lower your risk of heart disease by reducing total fat, by reducing saturated fat, by replacing that with polyunsaturated fat, and by reducing dietary cholesterol.  

But Dayrit and Newport's 2024 study says that might not be the case after all, arguing that Keys' research has led to “flawed dietary recommendations.”

"Reducing total fat intake was not proven to have any effect on lowering cholesterol levels or dying from heart disease," Dayrit and Newport began.

They also noted that "saturated fat included trans-fats, which raise total cholesterol and assumed all saturated fatty acids have the same effects on total cholesterol, and that dietary cholesterol does not account for the complexity of cholesterol metabolism."  

According to Dayrit and Newport, Keys' lipid-heart hypothesis gave too much focus on heart disease at the expense of looking into the role of trans-fats in cancer, obesity, and other metabolic disorders.

They also pointed out that Keys erroneously conflated saturated fats found in meat and dairy with harmful industrial trans fats commonly used in margarine and shortening, and coconut oil.

“Numerous observational, epidemiological, interventional, and autopsy studies have failed to validate the Keys equation and the lipid-heart hypothesis. Nevertheless, these have been the cornerstone of national and international dietary guidelines,” Dayrit and Newport said in their paper, published on the open-access Nutrients journal.

According to Dayrit and Newport, the dietary guidelines based on Keys lipid-heart hypothesis “are outdated and not supported by scientific evidence.”

They underscored the need to distinguish between different types of fats and advocate for a more nuanced approach to dietary recommendations, which should provide a more comprehensive understanding of the role of fats in one's diet and their impact on health.

Since its publication in May 2024, Dayrit and Newport's study has received an impressive 4,931 views, an achievement for which they have been cited.

A 2021 study in the Journal of the American Heart Association shared the same findings with Newport and Dayrit, with the research concluding that saturated fat intake, like beef, lamb, pork, lard and cream, butter, and cheese to name a few, has no direct effect on the risk of developing a heart disease.

— LA, GMA Integrated News