A new study challenges the long-held belief that saturated fat is the primary driver of heart disease. It questions the foundation of modern dietary guidelines. For decades, the “lipid-heart hypothesis” proposed by Ancel Keys in 1953 has shaped recommendations to limit saturated fat intake. Yet, a recent review paper by Ateneo de Manila University’s Dr. Fabian Dayrit and Dr. Mary Newport argues that Keys’ hypothesis and accompanying equation are flawed and unsupported by evidence.
The paper, published in the open-access journal Nutrients, highlights a critical mistake by Keys. He mistakenly conflated healthy saturated fats found in foods like meat and dairy with harmful industrial trans-fats. The researchers contend that this error led to a misguided focus on saturated fat. It overlooked the detrimental effects of trans-fats on heart health, cancer, obesity, and other metabolic disorders.
“Several studies have been incapable of validating the Keys equation and the lipid-heart hypothesis,” the researchers state. Despite this lack of evidence, the hypothesis has remained a cornerstone of dietary guidelines worldwide.
The study emphasizes the strong link between trans-fats, commonly found in processed foods, and heart disease. It also criticizes the widespread promotion of polyunsaturated fats, particularly linoleic acid. The study argues that an imbalance in omega-6 and omega-3 fatty acids can increase the risk of inflammation.
Dayrit and Newport advocate for a more nuanced approach to dietary recommendations. They urge a shift away from the outdated lipid-heart hypothesis. Their work prompts a critical reassessment of current dietary guidelines. It highlights the need to differentiate between various types of fats to improve public health.
