The Truth About Diet and Cancer

Some recent studies suggest that a low-fat diet will not reduce cancer rates, but the facts speak for themselves.

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Cutting Your Risk of Cancer

It feels like déjà vu all over again. In February 2006, headlines proclaimed “Low-Fat Diet Does Not Cut Health Risks.” Data from the Women’s Health Initiative (WHI) study concluded that a low-fat diet did not reduce the risk of breast cancer. Some women said, Why bother? There’s nothing I can do.

That concerns me. In 30 years of research, I’ve seen what a difference comprehensive lifestyle changes can make. The problem with the WHI study was that most of the women didn’t alter their diets very much. But those who achieved the greatest reduction in fat intake did have a decreased risk.

Now comes another study, and more confusion. In July, findings from the Women’s Healthy Eating and Living Study were released. Some 1,500 women previously treated for early-stage breast cancer were asked to cut fat to 15% to 20% of their calories and to eat more fruits and vegetables.

But they reported eating more fruit at the beginning of the study than at the end. And their fat intake on average rose, from 28.5% of calories to 28.9%. However, women who consumed less than 23.8% of calories from fat did have a significantly lower risk of breast cancer than those who got more than 33.4%.

Other studies have also found that diet can have a profound effect on cancer risk. In one, breast cancer survivors who lowered their fat intake to 20% (about 33 grams a day) cut their risk of recurrence after five years by 24%, compared with those who ate 51 grams of fat a day. An NIH-AARP study concluded, “Dietary fat intake was directly associated with the risk of postmenopausal invasive breast cancer.” And Swedish researchers found a direct link between a high fat intake among postmenopausal women and breast cancer. In the Harvard Nurses’ Health Study II, mostly premenopausal women who ate the most animal fat had a higher risk of breast cancer.

What is it about fat? One theory is that certain types cause inflammation and trigger estrogen, both of which may promote cancer.

Bottom line: When you stick to a low-fat, healthy diet, you not only feel better, you really can lower your risk of cancer.

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