Saturated fat in diet linked with higher mortality

Replacing animal fats in your diet with a variety of liquid vegetable oils can help you live longer as researchers have confirmed that higher consumption of saturated and trans fats is linked with higher mortality.

In a large study population that included 126,233 participants who were followed for more than three decades, researchers found that replacing saturated fats with unsaturated fats conferred substantial health benefits. 

The study suggests that replacing saturated fats like butter, lard, and fat in red meat with unsaturated fats from plant-based foods like olive oil, canola oil, and soybean oil can confer substantial health benefits.

"There has been widespread confusion in the biomedical community and the general public in the last couple of years about the health effects of specific types of fat in the diet," said Dong Wang, doctoral candidate at Harvard T.H. Chan School of Public Health and lead author of the study.

Trans fats had the most significant adverse impact on health. Every two per cent higher intake of trans fat was associated with a 16 per cent higher chance of premature death during the study period. Higher consumption of saturated fats was also linked with greater mortality risk.

Conversely, intake of high amounts of unsaturated fats, both polyunsaturated and monounsaturated, was associated with between 11 per cent and 19 per cent lower overall mortality compared with the same number of calories from carbohydrates.

The study was published online in the journal JAMA Internal Medicine.

The health effects of specific types of fats depended on what people were replacing them with, the researchers found. 

People who replaced saturated fats with carbohydrates had only slightly lower mortality risk.

Among the polyunsaturated fats, both omega-6 -- found in most plant oils -- and omega-3 fatty acids found in fish and soy and canola oils, were associated with lower risk of premature death. 

"Our study shows the importance of eliminating trans fat and replacing saturated fat with unsaturated fats, including both omega-6 and omega-3 polyunsaturated fatty acids. In practice, this can be achieved by replacing animal fats with a variety of liquid vegetable oils," Frank Hu, Professor at Harvard Medical School, said.