• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Research: Cutting Fat Doesn't Reduce Cancer Risk in Women

Posted on: Wednesday, 8 February 2006, 09:00 CST

By Rebecca Vesely, STAFF WRITER

Eating less fat did not lower the risk of cancer or heart disease in older women, suggesting that the link between fat and health is not as clear as conventional wisdom teaches, according to a nationwide study to be released today.

This does not mean women should swap their salads for potato chips, however.

The nearly 49,000 postmenopausal women ages 50 to 79 who participated in the largest study to date on fat and cancer risk may have started eating healthy too late or not reduced fat intake enough.

And the long-running study, designed a decade ago, did not take into account the difference between bad fats, such as saturated and trans fats found in processed and fast foods, and good fats, such as those found in fish, nuts, olive oil and avocado.

"It's a matter of when you reduce the fat, what are you replacing it with?" said Bette Caan, a nutritional scientist at Kaiser Permanente's Research Division in Oakland and a lead investigator of the study.

In other words, switching from full-fat

ice cream to low-fat ice cream is not as beneficial as replacing ice cream with fruit, Caan said.

The $415 million, eight-year study at

40 centers nationwide was designed to evaluate a low-fat diet's effect on cancer risk. Investigators also evaluated the data for cardiovascular risk.

The results showed no difference in the rates of breast cancer, colon cancer or heart disease among women who ate a low-fat diet and those who ate whatever they wanted.

In two exceptions, the women who started out with the highest fat intake did lower their risk of developing breast cancer after reducing the amount of fat they ate, and women who ate the fewest of the worst fats had less incidence of heart disease.

About 70 percent of the women who participated in the study were considered overweight or obese, and altering exercise pattern was not included in the study.

Some women failed to meet benchmarks set by researchers. The majority of women assigned to the low-fat diet did not reach a goal of making fat only 20 percent of their total caloric intake. On average, the women reduced their fat intake to 24 percent of total calories in the first year but then gradually increased their fat intake to 29 percent in the sixth year.

Women in the control group that did not reduce fat intake averaged fat intake of 35 percent of total calories in the first year and 38 percent in the sixth year. Women in both groups started with 35 to 38 percent of calories from fat.

U.S. dietary guidelines recommend keeping fat intake to between 20 and 35 percent of total calories, and limiting saturated fats to less than 10 percent of total calories.

The findings were published in today's Journal of the American Medical Association and are part of the Women's Health Initiative, an ongoing government study of thousands of postmenopausal women.

Marcia Stefanick, a professor of medicine at the Stanford Prevention Research Center and chairwoman of the WHI steering committee, said the results are not necessarily disappointing.

"Rather than trying to eat 'low fat,' women should focus on reducing saturated fats and trans fats," Stefanick said.

The results were not surprising because the trial did not test up- to-date dietary guidelines for preventing heart disease, wrote Cheryl Anderson and Lawrence Appel of the John Hopkins University Bloomberg School of Public Health.

"Dietary changes can have powerful, beneficial effects on cardiovascular risk factors," Anderson and Appel wrote in an accompanying editorial. "To reduce the risk of cardiovascular disease, individuals should maintain a desirable body weight, be physically active, avoid tobacco exposure and eat a diet consistent with national guidelines."

Caan said the same is true for cancer risk, saying the study's findings do not contradict national health guidelines.

"You should still consider low-fat choices, but pay attention that you have adequate fruit, vegetables and fiber, and be sure to exercise," Caan said.

Contact Rebecca Vesely at rvesely@angnewspapers.com.

Source: Oakland Tribune

More News in this Category