What if someone told you that you could live longer by incorporating fat into your diet? Well, according to a team of researchers at Harvard’s School of Public Health, incorporating the right kind of fat into your diet could benefit you in the long run. The new study, published in the JAMA Internal Medicine, is the result of 30 years of research to help debunk the longstanding misconception about dietary fats.

"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 the study’s lead author Dong Wang, a doctoral candidate in the departments of nutrition and epidemiology at Harvard Chan School, in a statement. "This study documents important benefits of unsaturated fats, especially when they replace saturated and trans fats."

For their research, Wang and his team examined the diets, lifestyles, and medical records of 126,233 participants from two large, long-term studies. Every two to four years, the participants were asked about their health for up to 32 years, during which 33,304 died. Researchers zeroed in on each person’s diet and how it affected their overall health and lifespan.

It turns out that the more saturated fat a person ate, the more likely they were to die from heart disease, cancer, neurodegenerative disease, or respiratory disease. For every 5 percent increase of saturated fat they consumed, they increased their risk of death by 8 percent. On the flipside, the more unsaturated fat a person incorporated into their daily diet, the more likely they were to live longer. Overall, those who ate the highest amount of unsaturated fat had slashed their risk of death by 11 to 19 percent.

The Difference Between Fats

Fat is a major source of energy for human beings; however, not all fats are created equal. According to Harvard Medical School, saturated fats are among the most common type of food in the American diet. Any fat that becomes solid at room temperature — from red meat and cheese to baked goods and butter — is considered a saturated fat.

The American Heart Association warns consumers that saturated fats raise bad cholesterol (LDL) levels in your blood, which in turn increases your risk for heart disease and stroke. This also explains why, with 30 years’ worth of data, researchers found those who ate more saturated fats also died from heart disease.

Fats don’t have to hurt your heart though. Unsaturated fats, such as monounsaturated and polyunsaturated fats, give a healthful boost to longevity. Good fats come mainly from olive oil, peanut oil, canola oil, avocados, most nuts, and omega-3 fatty acids found in fish. By incorporating these fats into your diet, you may be protecting your heart from future disease.

According to the study’s senior author Frank Hu, professor of nutrition and epidemiology at Harvard Chan School: "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."

Source: Wang DD, Hu F, Li Y, and Chiuve SE, et al. Specific Dietary Fats in Relation to Total and Cause-Specific Mortality. JAMA Internal Medicine. 2016.