:Low-Fat Diet May Reduce Your Risk of Deadly Ovarian Cancer by 40%


THE MASSIVE Women's Health Initiative (WHI) may finally have produced encouraging news: A low-fat diet seems to reduce postmenopausal women's risk of ovarian cancer — and women with the unhealthiest diets benefit the most from cutting down on fat.

Writing in the Journal of the National Cancer Institute, researchers reported that women who reduced their fat intake had a 40% lower risk of ovarian cancer after four to eight years, compared to those who made no dietary change. The randomized controlled study looked at data on nearly 50,000 women who participated in the WHI dietary modification trial, which tested whether a low-fat diet could reduce the risks of cancers and cardiovascular disease. (Other "arms" of the WHI, funded by the National Institutes of Health, studied hormone therapy and calcium/vitamin D supplementation.) Earlier analysis of the dietary intervention had found no significant benefit against colorectal cancer or heart disease, although a trend toward a breast-cancer benefit.

"We're really pleased to have something positive to say to American women," commented co-author Ross L. Prentice, PhD, of the Fred Hutchinson Cancer Research Center. "Undertaking a low-fat diet likely reduces your risk of ovarian cancer and perhaps other cancers as well."

The trial involved women initially ages 50 to 79, of whom 19,541 were assigned to a diet with no more than 20% of calories from fat; they replaced fat calories with fruits and vegetables (at least five servings daily) and grains (at least six servings daily). A control group of 29,924 women were asked to retain their usual dietary pattern. Both groups of women started the study averaging more than 35% of calories from fat.

Sticking to the low-fat diet proved tricky, which some experts pointed to as one possible source of previous disappointing results. After a year, the low-fat group had managed to cut fat intake to 24% of calories. By the end of the average 8.1-year followup period, however, that figure had gone back up to 29% — still lower than the 37% figure for the control group.

In the first years of the study, the low-fat diet showed little benefit against ovarian cancer. A stronger effect, however, emerged as time went on. The benefit was especially notable for women who began the study in the top third of percentage of calories from fat and in those with the highest total fat consumption.

Although ovarian cancer is relatively rare — striking about one in 60 women, versus one in nine for breast cancer — prevention is crucial because it's difficult to diagnose before the cancer has spread: The five-year survival rate is only 45%. According to American Cancer Society estimates, 22,430 American women will be diagnosed with ovarian cancer this year, and 15,280 will die of the disease. Risk for ovarian cancer increases with age.

Fat may play a role, the researchers suggested, by boosting levels of estrogen in the blood. The low-fat diet subjects showed a 15% reduction in blood levels of a key form of estrogen, estradiol, while the control group saw no change. Excess estrogen might in turn overstimulate the ovaries, increasing the risk of tumor formation.

TO LEARN MORE: Journal of the National Cancer Institute, Oct. 17, 2007; abstract at . American Cancer Society .

Living Lean

Simple tips from the American Cancer Society for reducing dietary fat, even when eating out or traveling:

Learn the "red flag" words that signify high-fat foods on menus: puffed, battered, creamy, crispy, breaded, buttery, hollandaise, flaky, au gratin, a la king, alfredo, Bearnaise, scampi and Mornay.

Traveling? Pack portable, low-fat snack foods such as crackers, raisins, pretzels, fruits, raw vegetables, fat-free cookies, fat-free muffins, bagels and air-popped popcorn.

Most airlines offer low-fat foods as part of their menus. Call in advance and request the low-fat alternative.

Keep a supply of easy-to-grab, low-fat foods handy. Such foods can include: instant vegetable soups and oatmeals, dried fruit, snack-size whole-grain cereal, mini-cans of water-packed tuna, pretzels and low-fat crackers.

If fast food is the only option, choose low-fat menu items such as a salad or grilled chicken sandwich. A submarine sandwich with lean meats and lots of vegetables (hold the mayo!) can be a healthier option as well.

Remember that fat-free doesn't mean calorie-free! It's still important to watch portion sizes.

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