Feb. 10, 2015 -- For years we’ve been told to eat a low-fat diet to protect ourselves from heart disease.
But a new report says those guidelines -- which recommend keeping fat to 30% or less of daily calories and saturated fat to 10% or less -- were not backed by solid research when they were first issued decades ago.
The report’s authors even say dietary advice “should not have been introduced” at all.
U.S. public health officials made the recommendation in 1977, and 6 years later those in the U.K. did the same, in efforts to curb heart attacks and heart disease.
Officials acknowledged the evidence wasn't conclusive when the guidelines were issued. The authors of the new report say that's an understatement.
"The evidence was never there," says James J. DiNicolantonio, PharmD. He's a research scientist at St. Luke's Mid America Heart Institute in Kansas City, MO.
The new report echoes concerns of other experts, says Steven Nissen, MD, chair of cardiovascular medicine at the Cleveland Clinic. He says there needs to be a major shift in how doctors advise their patients on diet. Nissen was not involved in the new report.
A Look Back at the Studies
With his colleagues, DiNicolantonio searched medical databases to find studies that drove the recommendations. They found six relevant clinical trials that looked at the relationship between dietary fat, cholesterol levels, and heart disease.
The trials found that eating a lower-fat diet didn't reduce deaths from heart disease or any other cause, he says. In one case, a group that limited its saturated fat to 10% had more deaths from heart disease and other causes than those who didn't follow the 10% rule, he says.
Here are some other issues they found:
- The studies included more than 2,400 people, all of them men. There was no difference in death rates between men who ate low-fat diets and those who didn’t. Men in both groups were as likely to die of heart disease.
- All but one of the studies looked only at men who'd already had a heart attack, not at those who hadn't yet gotten heart disease.
- Although men who ate less fat had lower cholesterol, they weren’t less likely to die of heart disease or other causes.
- Five of the six studies used different approaches to reduce fat in people’s diets. Only one had participants follow the guidelines recommending that people eat less than 30% fat overall or 10% saturated fat.
source : Is the Advice on Fat in Your Diet Wrong?
