A large study from Harvard T.H. Chan School of Public Health found that replacing saturated and trans fats with healthy unsaturated fats, such as olive oil, canola oil, and soybean oil, lowers your risk of death and other serious health issues.
Yet another study confirms what we've been saying about fat for some time: the right kinds of fat can contribute to a healthy lifestyle, and the wrong kinds of fat can negatively impact your health.
This study, which was published this week in JAMA Internal Medicine, followed and documented the diets (specifically the types of fats consumed) of more than 126,000 people in two studies over three decades.
Researchers discovered associations between saturated and trans fats and a higher risk of early death. Artificial trans fats, which the FDA is requiring companies remove from their foods by 2018, had the most significant impact on health. Every 2 percent higher intake of the fat was associated with a 16 percent higher chance of early death. Plus, trans fats are connected with a myriad of health problems, including heart disease and type 2 diabetes.
Higher rates of saturated fat intake showed higher risks for premature death as well, but those numbers weren't as high as the ones found for trans fats. Although saturated fats are generally considered unhealthy, a recent study showed that butter in moderation doesn't increase your risk for heart disease. But be judicious in how you use them.
The foods swapped in for saturated fats might be most detrimental to our health. People who substituted carbohydrates for saturated fats in their diets fared slightly better than people who ate more saturated fat, but their overall risk of death was still higher than people who chose unsaturated fats. Those carbohydrates tend to be highly-processed starches and sugar, which have their own host of negative health consequences.
The real winner in this study? Unsaturated fats. The researchers found this type of fat was linked to a lower risk of early death. People who ate high amounts of polyunsaturated and monounsaturated fats had between 11 percent and 19 percent lower risk for death compared to people who ate the same amount of calories from carbohydrates. People in the study who swapped saturated fats for unsaturated ones had significantly lower rates of cancer, cardiovascular disease, neurodegenerative disease, and respiratory disease.
Sticking to wholesome unsaturated fat sources—our Healthy Guide to Fats is a good starting point—and using sources of saturated fat, like butter and meat, in small but flavorful ways will help you get a better, healthier balance of these important nutrients in your diet.