A new study, funded by our organization and presented at the European Society of Cardiology Congress 2024 in London, reveals that a diet high in saturated fat poses a greater risk to heart health compared to a diet high in unsaturated fat, even without weight gain.
The research highlights significant changes in heart health markers among individuals who consumed a high-saturated-fat diet without experiencing weight gain. After just 24 days, participants on this diet showed a 20% increase in liver fat and a 10% rise in blood cholesterol levels.
Dr. Nikola Srnic, a researcher from the University of Oxford, explained:
“Our study investigates how different types of fat affect heart disease risk beyond weight changes. The results indicate that saturated fat can negatively impact cardiovascular risk factors even without weight gain. Conversely, diets rich in polyunsaturated fats appeared to have protective benefits. These early findings suggest that different fats can significantly impact health over a short period.”
Increased Risks
Saturated fats, commonly found in butter, fatty meats, cakes, and pastries, have been linked to higher heart disease risks. In contrast, polyunsaturated fats, including omega-3 and omega-6 found in oily fish, sunflower oil, and certain nuts, are known to provide essential nutrients and may offer health benefits.
In the study, 24 participants followed diets high in either saturated or polyunsaturated fats for up to 24 days. MRI scans and blood tests were conducted before and after the diet to evaluate the impact on heart disease risk factors.
Despite no change in body weight, those consuming saturated fats exhibited concerning health indicators. They experienced a 10% increase in total and ‘bad’ cholesterol levels and a 20% rise in liver fat. Excessive liver fat is associated with higher risks of type 2 diabetes and cardiovascular diseases.
Protective Effects of Polyunsaturated Fats
Participants on a polyunsaturated-fat diet showed beneficial effects. Their total and ‘bad’ cholesterol levels decreased by about 10%, and their heart muscle’s energy reserves increased.
The study also explored how polyunsaturated fats affect heart cells. Cells exposed to polyunsaturated fats were more effective in breaking down fat for energy. This mechanism might explain how such fats help reduce blood fat levels.
Professor James Leiper, Associate Medical Director, stated:
“Saturated fat is known to elevate heart disease risk. This study confirms that saturated fat can adversely affect heart health rapidly, without altering body weight. The lab results offer insights into these effects, though further long-term studies are needed to determine if these short-term changes lead to serious heart problems.”
The researchers emphasize that additional studies with more participants are required to validate these findings and assess their long-term implications for heart health.
