Low-Fat Diet Checks Return of Breast Cancer, Study Says
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From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.
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There's been encouraging news lately about the fight against breast cancer. Older drugs are working better than researchers expected. New drugs show great promise. But the latest advance in breast cancer isn't a drug, as NPR's Richard Knox reports.
RICHARD KNOX reporting:
The idea that a low-fat diet might prevent breast cancer recurrence goes back more than two decades, but the first attempt to study it, in 1983, didn't generate much enthusiasm. Women didn't enroll; many scientists didn't think it was worth studying. But a big study finally got under way. It included 2,400 women who all had surgery for early-stage breast cancer. They all got radiation, chemotherapy and hormone therapy as their doctors thought best, but some ate a typical high-fat American diet and some drastically cut their daily fat intake. The results came out today at a medical meeting in Orlando. Dr. Rowan Chlebowski of UCLA led it.
Dr. ROWAN CHLEBOWSKI (UCLA): After about five years, women who reduced their dietary fat intake had about 24 percent less chance of having the breast cancer come back.
KNOX: A 24 percent reduction in recurrence of breast cancer is a big deal. That's according to Sandra Horning; she's president of the American Society for Clinical Oncology.
Ms. SANDRA HORNING (President, American Society for Clinical Oncology): The magnitude of effect is comparable to some of the common interventions we use to lower the risk of breast cancer, such as chemotherapy, hormonal therapy or a combination of the two.
KNOX: But the surprise is that the low-fat diet produced even bigger benefits for some women, those who had breast cancers that did not respond to estrogen. This is called estrogen-receptor-negative cancer.
Ms. HORNING: At first blush, you might guess that there would be a greater impact in the estrogen-receptor-positive group, whereas just the opposite was found.
KNOX: Researchers have thought a low-fat diet might shrink breast tumors by depriving them of estrogen, since fat cells produce estrogen. The new study shows that a low-fat diet must work through a different mechanism, such as reducing insulin levels. That'll be the focus of further research. Meanwhile, many women will want to know just how hard it is to follow the breast cancer prevention diet. The diet in the study was very low in fat, but it wasn't designed to take off weight. In fact, study participants lost only four pounds on average.
Dr. GEORGE BLACKBURN (Harvard University): I don't think the women felt they were deprived.
KNOX: Dr. George Blackburn is a nutrition expert and study co-author at Harvard. He says women in the study reduced their fat intake by 40 percent.
Dr. BLACKBURN: All it requires you to do is to get rid of the junk food, Danishes and adding too much butter, margarine, oils to your food; have lean cuts and low-fat dairy, and you got rid of 20 grams of fat. You're now at 20 percent of your calories, which is the lower range of recommended fat intake per day by the new 2005 Food Guide.
KNOX: Maureen Ruhl is a California woman in the study.
Ms. MAUREEN RUHL (Study Participant): I didn't really feel I had to do without, but I did cut back. Instead of having ice cream after dinner every night, you know, I'd allow myself once or twice a week maybe. We used to eat the big breakfast on a Sunday morning, bacon and sausage, you know, the good stuff. And so we started to change the pattern.
KNOX: A nutritionist helped her to shop for lower-fat foods and change her cooking techniques. Ruhl says it all helped her cope with cancer.
Ms. RUHL: When you first find out about cancer, it's this awful feeling that something foreign, something strange has invaded you, and you feel like you've lost control.
KNOX: Rowan Chlebowski, the study leader, says the research may ultimately help breast cancer patients feel there's something they can do to stay healthy. He says it's too soon to advise them to go on a low-fat diet, but patients might decide to do it on their own.
Dr. CHLEBOWSKI: You don't want to make women feel guilty if they choose not to make such a change. But if a woman looking over this decides that this might be something that they could do and find out it isn't much of a burden for them, that certainly could be a reasonable option.
KNOX: Two more studies are coming soon to help define the role of diet in breast cancer. Later this year scientists should know if a low-fat diet prevents first-time breast cancers. Richard Knox, NPR News.
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