Fate Plays No Role in Cancer Development
Experts say the choices people make, plus genetics, determine risk

(HealthDay News) -- Cancer doesn't "just happen," researchers now believe. And because of that, they maintain, there's plenty that people can do to protect against the disease.

Birth weight, childbearing, breast-feeding, adult height and weight, exercise and nutrition are among the factors that have been shown to influence the risk of developing cancer.

"We need to think about cancer as the product of many long-term influences, not as something that 'just happens,' " Dr. Walter Willett, a professor of epidemiology and nutrition at the Harvard School of Public Health and co-author of a report on cancer risk and prevention, said in a prepared statement.

"Examining the cause of cancer this way, across the entire lifetime, is called the life course approach," Willett said.

The report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective , was prepared by an international team of scientists who analyzed more than 7,000 studies and identified a definite connection between excess weight and cancers of the esophagus, pancreas, colon and rectum, endometrium and kidney, as well as breast cancer in postmenopausal women.

The report also found that breast-feeding can reduce a mother's risk for breast cancer and that breast-fed babies are less likely to become overweight or obese, which lowers their risk of developing cancer.

In addition, tall people might have an increased risk for colorectal, ovarian, pancreatic and postmenopausal breast cancer, the report found.

Increased risk, though, does not mean that a person is destined to develop cancer.

"Risk isn't fate," Willett said. "The evidence clearly shows that risk can be changed. We wanted to point these emerging links out, because we now believe them to be more important than the scientific community, much less the public, has yet realized."

"Whether or not we get cancer has to do with our genes and with the choices we make every day," he said. "Our cancer risk is also influenced by our whole accumulated life experience, from conception onwards."

Willett and his colleagues offered a number of recommendations for cancer prevention, including:

• Getting at least 30 minutes of exercise a day.
• Staying lean.
• Limiting intake of red meat.
• Avoiding processed meats.
• Limiting consumption of alcohol.

"These findings are right on," Colleen Doyle, director of nutrition and physical activity for the American Cancer Society, told HealthDay . "They are consistent with our own nutrition and physical activity guidelines. They clearly put emphasis where the emphasis needs to be, and that's on controlling your weight."

Though not smoking is the most important thing a person can do to reduce the risk of cancer, "there are estimates that obesity will overtake smoking as the leading preventable cause of death," Doyle said. "It's great to see another report that emphasizes that being active, watching your weight and eating a healthy diet are not only going to help you reduce your risk of cancer but heart disease and diabetes as well."

Karen Collins, a nutrition adviser at the American Institute for Cancer Research, described the findings as "a good-news report."

"If we are watching our weight, working regular physical activity into our daily life and eating a healthy balance of foods, we could prevent a third of cancers," she told HealthDay .

Excess weight "is not dead weight," she noted. "It's an active metabolic tissue that produces substances that promote the development of cancer."

On the Web

To learn more about cancer prevention, visit the U.S. National Cancer Institute.

SOURCES: HealthDay News , Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective , American Institute for Cancer Research and World Cancer Research Fund, Oct. 31, 2007; Colleen Doyle, M.S., R.D., director of nutrition and physical activity, American Cancer Society, Atlanta; Karen Collins, M.S., R.D., nutrition adviser, American Institute for Cancer Research, Washington, D.C.
Author: Robert Preidt
Publication Date: Oct. 31, 2008
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