Circulation, an AHA journal, published the findings that diets rich in omega-6 fatty acids prove to be heart healthy. Dr. William Harris, Ph.D., and colleagues from the Sanford School of Medicine at the University of South Dakota, felt it was important to objectively evaluate reports that omega-6s promote inflammation and thus may increase heart disease risk.
In a statement from AHA, Dr. Harris says, "That idea is based more on assumptions and extrapolations than on hard data." While an acid that causes early stages of inflammation may be formed from omega-6s, they also produce anti-inflammatory properties--particularly in the lining of blood vessels--that are much stronger.
After reviewing results of more than two dozen controlled and observational studies, Dr. Harris determined that participants in the controlled trials consuming diets higher in omega-6s had less incidence of heart disease than those whose omega-6 intake was low. A meta-analysis of several trials indicated that replacing saturated fats with omega-6 lowered heart disease risk by 24 percent.
Soybean oil is about 50 percent omega-6 fatty acids, one of the most concentrated sources, while olive oil and canola oil are both low in omega-6s. Soybean oil is commonly labeled vegetable oil in the grocery store--check the ingredients label to be sure.
"The news that soybean oil may lower heart disease risk when replacing oils with higher levels of saturated fat is especially important," says Lisa Kelly, RD, MPH, of the United Soybean Board.
The advisory recommends Americans aim for 5 percent to 10 percent of their daily calories from omega-6 fatty acids. The recommended daily intake of omega-6s ranges from 12 grams to 22 grams depending on age, gender, and physical activity.