Which Fats Really Are Good for Your Heart?
What did the study find?
When Ramsden compared the two groups three years later, the group told to boost omega-6 fats fared worse, he says. "Death from all causes was about 65% higher, and death from coronary heart disease was about 70% higher," he says.
Even when researchers included additional data from earlier studies, they still found a possible increased risk of heart disease with higher omega-6 intakes. The researchers found a link but cannot prove cause and effect.
Why might omega-6 fats be risky for heart health?
One possible explanation, Ramsden says, is that although omega-6 fatty acids lower LDL (the ''bad'' cholesterol) overall, ''it may increase oxidized LDL," he says.
"Oxidized LDL contains free radicals, which are hazardous substances that may contribute to heart disease," he says.
Would the study findings apply only to those who have already had a heart attack, or also to others?
Ramsden can't say, as the study just included those with heart disease.
What does the American Heart Association recommend about omega-6 fat intake?
In a 2009 advisory, the AHA says that taking in 5% to 10% of calories from omega-6 fatty acids lowers the risk of heart disease. Besides vegetable oils, omega-6 fatty acids are also in nuts and seeds.
Will the new study result in the AHA taking another look?
"Certainly the results are important to consider," says Alice Lichtenstein, D.Sc., professor of medicine at Tufts University and a spokeswoman for the American Heart Association. Although the association won’t be drawing any immediate conclusions for Americans, she says it ''does say we probably should be reevaluating the recommendation."
What should we do now when it comes to watching how much fat we eat?
"Stay the course," Lichtenstein says. That means ''a moderate fat intake with relatively low saturated and trans fat, and the balance of unsaturated including polyunsaturated and monounsaturated [such as olive oil]."
''People don't eat in percents," she says. "Limit animal fat, such as meat and dairy fat, and partially hydrogenated oils [or trans fats, found in baked goods and fried foods]. Use liquid vegetable oil."
For those who count their fat grams: If you eat 2,000 calories a day, total fat intake should be 56 to 77 grams, according to the American Heart Association. Most of that should come from unsaturated fats.
Ramsden and others suggest picking products with lower amounts of omega-6. To do so, choose canola or olive oil, Ramsden says, instead of safflower or sunflower.
"The concerning foods would be oil sources of safflower, corn, and sunflower, because they have almost no omega-3 and higher levels of omega-6," says Richard Bazinet, PhD, associate professor of nutritional sciences at the University of Toronto.