Low fat diet's disease prevention benefits overstated
A study says that merely switching on to a low fat diet does not reduce the risk of breast cancer or heart disease in women.india Updated: Feb 09, 2006 11:55 IST
A new study has revealed that merely switching on to a low fat diet does not reduce the risk of breast cancer, colorectal cancer or heart disease, in women, instead they should cut back on saturated and trans fats.
A Stanford University School of Medicine researcher showed a modest reduction in breast cancer among the women who started with the highest fat intake before cutting back. And it also suggested a health benefit for women who reduced their consumption of saturated and trans fats.
"Just switching to low-fat foods is not likely to yield much health benefit in most women," said Marcia Stefanick, PhD, professor of medicine at the Stanford Prevention Research Center and chair of the WHI steering committee.
"Rather than trying to eat 'low-fat,' women should focus on reducing saturated fats and trans fats." She also recommended that women eat more vegetables, in particular dark, leafy greens and cruciferous vegetables, though the trial did not specifically study these foods.
The dietary findings are reported in three studies to be published in the Feb. 8 issue of the Journal of the American Medical Association.
The low-fat diet study involved nearly 49,000 postmenopausal women between the ages of 50 and 79 who were tracked over the course of a little more than eight years on average, making it the nation's largest long-term study of a low-fat diet. The goal was to test a widely held theory that low-fat diets helped reduce the risk of cancer and heart disease.
Furthermore, the study showed that women who had the highest fat intake at the study's outset showed greater evidence for reducing their breast cancer risk on the diet program. There was also a suggestive trend of breast cancer risk reduction for women who initially had the lowest consumption of vegetables and fruits and then increased their intake by one serving per day as part of the diet.
Regarding the heart disease findings, Stefanick noted that the women weren't asked to differentiate between "good fats" (the unsaturated fats found in fish, nuts and vegetable oils) and "bad fats" (saturated fats and trans fats found in processed foods, meats and some dairy products), which is emphasized in current guidelines for heart disease reduction.
"This shows that you can't rely on using low-fat substitutes to make a difference," Stefanick said. "You really need to think about what kinds of fats you're eating and the foods that should be part of your diet, such as vegetables, for instance."
For women who want to maintain their health, Stefanick advised them to follow a diet low in saturated and trans fats, and rich in vegetables and fiber - rather than to strive to eat "low-fat" foods.
She also advised them to pay attention to total caloric intake regardless of diet composition and to get adequate regular exercise. Women should also get routine mammograms and screenings for colorectal cancer and heart disease risk, including checking their cholesterol profile, blood pressure, blood sugar and body weight.
First Published: Feb 09, 2006 11:55 IST