How extra fat increases cancer risk; diet and exercise lower risk

CINCINNATI - We all want to fit into that swimsuit in June, or that special dress for the high school reunion.  But here's a compelling reason to watch your weight and your diet: it will help you fight cancer.

An article in the latest "Nutrition Action Newsletter" outlines how excess weight increases your risk of several cancers, including breast , colorectal, esophageal, pancreatic and endometrial cancer.

In breast cancer, after menopause, fat cells are the main source of estrogen, which promotes the growth of most breast cancers.

Researchers also suspect that higher insulin levels promote tumors.  As you become heavier, you're more likely to have higher insulin levels.

Regina Ziegler at the National Cancer Institute says that breast cancer patients who are more active and less overweight have a better chance of surviving the disease.

Susan Mayne of the Yale School of Health says in today's world, obesity dominates everything. She says, for instance, an NIH-AARP study found that people who were overweight had a 70 percent higher risk of esophageal adeno-carcinoma than those who were normal weight. She says pressure from a bigger belly may raise the odds of reflux.

In the case of prostate cancer, researchers at Harvard say most older men get prostate cancer, but those who engage in vigorous exercise, such as jogging or swimming, have a 70 percent lower risk of advanced cancer.