Eating Foods Fried in Healthier Oil Not Linked to Heart Disease, Researchers Find
By Kathleen Doheny
WebMD Health News
Reviewed By Louise Chang, MD
Jan. 24, 2012 -- Eating foods fried in healthier oils such as olive or sunflower is not linked to heart disease or premature death, Spanish researchers have found.
They followed more than 40,000 adults for 11 years, tracking fried food intake and heart disease.
However, this tentative morsel of good news for fried food fans comes with a heaping side dish of caution, especially when it comes to typical U.S. fried foods and diets.
"We should emphasize that our results were obtained within the context of a healthy diet, the Mediterranean one, and may not be replicated with other types of diets," researcher Pilar Guallar-Castillon, MD, PhD, MPH, associate professor of preventive medicine at Universidad Autonoma de Madrid, tells WebMD.
Another big difference between Spanish diners and U.S. diners may also play a role. "In our study, most meals were prepared and consumed at home," Guallar-Castillon says. It's difficult to know which type of oil you are eating, she says, when you are dining out.
The study is published online in BMJ.
Fried Food and Heart Disease: Study Details
Eating large amounts of fried food has been linked with heart disease risk factors such as high blood pressure, lowered ''good'' cholesterol, and obesity, the researchers write.
However, research on fried food and heart disease itself has produced conflicting results.
The researchers evaluated 40,757 adults, ages 29 to 69 and free of heart disease when they enrolled in the study in 1992 through 1996. The researchers followed them until 2004.
The researchers interviewed the men and women at the start of the study about their usual eating habits. They asked them what they'd eaten in a typical week during the previous year.
The questionnaire included up to 662 different foods, including 212 that were fried.
Frying methods included deep-fried, pan, battered, crumbed, or sautéed. Most used heart-healthy olive oil.
The researchers separated participants into four groups, depending on their intake of fried foods. The lowest group ate about 1.6 ounces of fried foods a day. The group with the highest intake had about 8.8 ounces a day. On average, the men and women ate a little less than 5 ounces a day of fried foods and used about a half-ounce of oil to fry it.
Fried food was about 7% of all food eaten.
During the follow up, 606 heart attacks and other heart ''events'' occurred, and 1,135 deaths occurred from all causes.
When the researchers looked at the heart disease and deaths, they found no link between fried food, whatever the intake, and heart disease or death from any cause.
As for why, Guallar-Castillon says, "Food was fried with oil rich in mono- and polyunsaturated fats, which are heart-healthy." Olive oil has antioxidants that may protect the heart.
Fried Foods and Heart Disease: Strive for a Balanced Diet
"This is an interesting study that provides some 'food for thought' but no conclusive evidence that frying is good for you," says Connie Diekman, RD, director of university nutrition at Washington University in St. Louis. She reviewed the findings for WebMD.
She notes some study limitations: Diet information was collected only at the start. And the information on cooking methods -- pan vs. deep fry -- was lumped together.
What matters, she tells WebMD, is how the whole diet balances out. "If someone chooses to prepare something by frying, then what goes with that food should be prepared in a different manner to keep the fat in the meal balanced," Diekman says.
The type of fat matters, she says. Olive oil, for instance, is viewed as more heart-healthy than trans fats. "Overall calorie intake counts, and too many calories from any type of fat isn't a good thing."
The diet habits studied appear quite different than those of typical U.S. consumers, says Andrea Giancoli, RD, MPH, a Santa Monica, Calif., dietitian and spokesperson for the Academy of Nutrition and Dietetics.
"The bottom line here is, most of what they were consuming were these healthful oils -- olive and sunflower -- and a lot of fish. The Mediterranean diet is different from ours," she says.
The study results are not surprising, given that most of the oils were the heart-healthy type, says Alice Lichtenstein, DSc, Gershoff Professor of Nutrition Science at Tufts University in Boston.
She says self-report of diet is another limitation, as it can be inaccurate. She notes that those who said they ate the highest amount of fried food took in about 600 more calories a day than those who said they ate little fried food, yet their body mass indexes were similar.
In an editorial that accompanies the study, Michael Leitzmann, MD, of the University of Regensburg in Germany, notes that the body of evidence refutes the myth that frying food is generally bad for the heart. "However," he writes, "this does not mean that frequent meals of fish and chips will have no health consequences."
Nutrition and Healthy Eating Resources
Guallar-Castillon, P. BMJ, published online Jan. 24, 2012.
Leitzmann, M. BMJ, published online Jan. 24, 2012.
Pilar Guallar-Castillon, MD, PhD, MPH, associate professor of preventive medicine, Universidad Autonoma de Madrid, Spain.
Connie Diekman, RD, director of university nutrition, Washington University, St. Louis.
Andrea Giancoli, RD dietitian, Santa Monica, Calif.; spokesperson, Academy of Nutrition and Dietetics.
Alice Lichtenstein, DSc, Gershoff Professor of Nutrition Science, Tufts University, Boston.
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