Less Fat, More Protection?
A new study suggesting that a low-fat diet may help reduce the recurrence of breast cancer in women has reignited interest -- and some debate -- about what level of fat is best to eat.
The study, presented at a conference last week, involved some 2,400 post-menopausal women, who had been diagnosed with early stage breast cancer. All participants received the same state-of-the-art medical care, but half were randomly assigned to meet with a nutritionist every two weeks and remained in contact for food advice between visits. The women were counseled to eat a very low-fat diet, with just 15 percent of calories coming from fat. Participants in the control group consumed a moderate diet, in which 30 percent of calories came from fat.
Led by Roman T. Chlebowski of the Los Angeles Biomedical Research Institute at Harbor-UCLA, the study found that about 10 percent of the women in the low-fat group -- compared with 12 percent of those on the control diet -- experienced a recurrence of breast cancer. That's a small but significant reduction in risk and the first solid evidence that changes in diet can improve the outcome for women with breast cancer.
Although the results have not yet been published in a scientific journal, the findings underwent peer review before being presented at the recent annual meeting of the American Society of Clinical Oncology and were considered important enough to be highlighted at a plenary session, a distinction reserved for just 10 of 3,800 abstracts submitted.
"It's an important study," said Peter Greenwald, director of cancer chemoprevention at the National Cancer Institute. "The message is that women with breast cancer might consider following a low-fat diet in addition to getting the best medical treatment at the same time."
The question is, how low in fat? Also, what might the benefits be for those without breast cancer? And how does this fit into what else is known about a healthy diet?
That's where "it gets complicated," noted Walter Willett, chairman of nutrition at the Harvard School of Public Health. He also wonders if the risk reduction shown in the study comes not just from eating less fat, but also from weight loss "or other changes that people made in their diets like eating more fruit and vegetables."
While researchers continue to assess the best course for women with breast cancer, they say there's plenty of evidence that the following tips will help promote health no matter what your sex or health status:
Lower the fat. Most people eat too much and the wrong kind of fat. Based on these new results, experts say that women who have been diagnosed with breast cancer may want to consider keeping fat intake at 20 percent of total calories -- the lower end of what the U.S. Dietary Guidelines recently recommended. Doing so can be challenging, since it pretty much means no added fat: no butter or margarine, no salad dressing with oil, no baked goods or other foods with added oil.
For almost everyone else, the current recommendation is to aim for about 30 percent of daily calories from fat.
Eat healthful fat . Regardless of how much fat is in your diet, reach first for foods that naturally contain healthful fat. Think seafood, nuts, avocados and olives. Limit added fat to six teaspoons or less (for a 2,000-calorie eating plan) and make it healthful fat, such as olive, canola or safflower oils.
In any case, skip fried food and minimize consumption of fatty meats--from bacon and salami to marbled steaks and poultry skin--as well as whole-fat dairy products. Ditto for cholesterol (found in egg yolks and organ meats). Keep trans fatty acids (found in many commercially prepared baked goods, snacks and frozen foods) as low as possible.