TUESDAY, March 23, 2010 (Health.com) — For years, experts have warned us to cut down on saturated fat—think butter, cheese, bacon, red meat, and countless other tasty foods—because it clogs arteries and causes heart attacks.
Now, new research suggests all that self-restraint may have been misguided. While saturated fat does indeed raise LDL (or bad cholesterol), mounting evidence suggests that the fat, in and of itself, may not be as bad for your heart as previously thought. But don’t rush out to the diner to order a big greasy breakfast just yet.
Cutting back on saturated fat is important, but not if you simply replace the calories with carbohydrates—such as those found in fat-free cookies, cakes, or other types of food. In fact, you need to replace saturated fat with polyunsaturated fats—the good fats found in nuts, vegetable oils, and fish—to get a benefit, according to a study published this week in the journal PLoS Medicine. Swapping these fats can lower your risk of heart disease by up to 19%, the researchers found.
“Saturated fat is not so bad for you that you can replace it with anything and get [a] benefit,” says lead study author Dariush Mozaffarian, MD, the co-director of the Program in Cardiovascular Epidemiology at Brigham and Women’s Hospital and Harvard Medical School, in Boston. “The replacement matters.”
Although doctors and nutrition guidelines have long advised people to reduce the percentage of calories in their diet from saturated fat, the question of what people should eat instead has remained largely unanswered, Dr. Mozaffarian says.
To address that question, he and his colleagues analyzed data from eight controlled clinical trials in which more than 13,000 people replaced saturated fat with polyunsaturated fat in their diets. Polyunsaturated fat accounted for up to 20% of the calories consumed by the people who were instructed to increase their intake of the fat during the studies; among the people in the control groups, it accounted for just 5% of the calories consumed, on average.
For every additional 5% in total calorie intake from polyunsaturated fat, the study participants’ risk of heart attack or heart-related death fell 10%, the researchers found. And the longer people stayed on a diet rich in polyunsaturated fats, the greater were the benefits to heart health.
“With all the focus on fat and saturated fat and cholesterol, we’ve put a lot of junk in our diet instead,” Dr. Mozaffarian says. “What a person needs to do is to eat the appropriate amount of calories, and eat a healthy, balanced diet.”
Next page: The evolving thinking on saturated fat
