Women's Health: Low-fat diet may prevent breast cancer recurrence

Cutting fat from the diet could be a lifesaver for women who've had a breast tumour removed in the early stages of cancer.

In a study of more than 2,000 women with early breast cancer, those who cut down on fats in their diet were 21 per cent less likely to suffer a relapse and 22 per cent less likely to die over the next six to seven years, compared with those who continued to eat their typical foods.

But the benefits of this approach were restricted to women whose tumours did not contain receptors for estrogen and progesterone – female hormones that can promote the growth of breast cancer. There was no significant benefit in women with hormone-receptor-positive tumours, but the 147 women who did not have these tumour receptors were 53 per cent less likely to suffer a recurrence and 66 per cent less likely to die than their 215 counterparts in the regular diet group.

"This was a dramatic finding. Mortality was reduced from 17 per cent to six per cent in this subgroup," says Dr. Rowan Chlebowski, chief of the division of medical oncology and hematology at the Los Angeles Biomedical Institute of Harbor-University of California at Los Angeles Medical Center in Torrance, Calif.

"That's as good or better than any treatment intervention we have for this type of disease," which is notoriously difficult to treat, says Dr. C. Kent Osborne, a breast cancer specialist at Baylor College of Medicine in Houston who was not involved with the work.

For the study, 2,437 postmenopausal women with early, surgically removed breast cancer were randomly assigned to a low-fat diet or their usual foods in addition to conventional cancer management. The intensive nutrition program included eight one-on-one sessions with a dietitian every other week, followed by quarterly visits, with the goal of reducing dietary fat intake to 20 per cent or less of daily calories.

Overall, patients who received the intensive counselling reduced the amount of fat in their diet from 57 to 38 grams per day, or from 29 to 19 per cent of their total daily calories. Over the followup period, they lost nearly three kilograms more than the women who ate their usual foods.

Chlebowski says making the changes is "all about substitution and reduction." Women are advised to have cereal and low-fat milk for breakfast instead of sweet rolls or baked goods; to snack on popcorn instead of cheese and crackers; to skip the spread on the bread and the dressing on the salad; and to reduce portion sizes of meats. Regular visits with a nutritionist are critical to sticking with the plan long term, he adds.