By Kate Stinchfield
MONDAY, Jan. 26, 2009 (Health.com) — For the first time, the American Heart Association has issued an advisory urging Americans to make sure they get an adequate intake of omega-6 fatty acids.
Omega-6 fatty acids are found vegetable oils, nuts, and seeds, and often don’t get as much attention as omega-3 fatty acids, which are found in fatty fish such as tuna, mackerel, and salmon. Increasing intake of omega-3 fatty acids can lower the risk of coronary heart disease; the AHA is concerned that there's a public perception that omega-6 fatty acids aren't as healthy as omega-3s and should be limited in the diet.
Both omega-3 and omega-6 are polyunsaturated fatty acids, or PUFAs, and are particularly beneficial when used to replace saturated fat or trans fatty acids in the diet, according to a science advisory published Monday in Circulation: Journal of the American Heart Association. The AHA recommends that people get 5% to 10% of daily calories from omega-6 polyunsaturated fatty acids, although most people in the United States already consume this amount via corn oil, cooking oil, nuts, and salad dressings. (Read more about the 10 best foods for your heart.)
The AHA issued the guidelines to counter the perception that omega-6 fatty acids may promote inflammation and possibly lead to increased cardiovascular risk, says William S. Harris, PhD, the advisory’s lead author.
“We think that’s just a bad message,” says Harris, a senior scientist at Sanford Research at the University of South Dakota. “Our current intake of omega-6s is good for heart health. It wouldn’t hurt for us to get more, but we shouldn’t be decreasing our intake.”
The team examined a wide variety of research studies in animals and humans before making the recommendation. They say having 5% to 10% of daily calories from omega-6 fatty acids, or 12 to 22 grams per day, is safe, and higher intakes “appear to be safe and may be even more beneficial.” The most commonly consumed omega-6 fatty acid is linoleic acid.
“There’s been some controversy in the nutrition community that omega-6 fatty acids—which have always been considered essential for heart health—are not actually good for the heart, and it’s been spilling out to the general public,” says Harris. “Science just doesn’t support that message.”
The AHA recommends getting an adequate intake of omega-6 through diet, rather than from supplements.
“It’s not really possible to get too much omega-6. Don’t be concerned with this idea that you’re going to give yourself heart disease," says Dennis Goodman, MD, clinical associate professor at the University of San Diego and the former chief of cardiology at Scripps Memorial Hospital. "The evidence is much more in favor of the fact that omega-6 lowers your risk of heart disease. A theoretical disadvantage has never been shown clinically.” (Read more about how dietary fats can help—or harm—your heart.)
But not all experts agree with the AHA's recommendation. The American diet is already packed with omega-6, says Fred Pescatore, MD, the author of The Hamptons Diet and the medical director of Medicine 369, a complementary medical center in New York. “Our foods are full of corn oil and grapeseed oil, both of which contain a ton of omega-6s," he says. "We really need to be increasing our omega-3 intake."
Dr. Pescatore says the high ratio of omega-6s to omega-3s in the American diet is one reason for the higher rates of cardiovascular disease compared to Japan, where a low ratio of omega-6 to omega-3 is more common.