FRIDAY, Oct. 24, 2003 (HealthDayNews) -- For more than three decades, the American Cancer Society has nagged, cajoled and inspired people to stop smoking, conducting such campaigns as the Great American Smokeout.
It also has gently persuaded the reluctant to get regular cancer screening checkups, such as Pap smears, prostate exams and mammograms, to drive down cancer rates.
Now, the cancer society hopes to persuade Americans that their widening girth isn't just an appearance problem or a heart-disease risk.
Too much weight also heightens the risk of many forms of cancer, although few Americans are aware of the link. Being overweight or obese seems to be responsible for 14 percent of all cancer deaths in men and 20 percent of cancer deaths in women, a large-scale study published earlier this year in the New England Journal of Medicine found.
Still, most Americans don't associate excess weight with cancer risks, says Colleen Doyle, a dietitian and the director of nutrition and physical activity for the American Cancer Society.
"We found that out from a benchmark survey we did in early 2002," she says. "Only 1 percent of people who responded said that weight loss was a way to reduce cancer risk. That said to us, we've got a big awareness problems. Let's connect those dots."
Earlier this year, the cancer society teamed with Weight Watchers International to start connecting those dots. Americans were invited to stop by participating Weight Watchers centers to get a free weigh-in and learn their BMI, or body mass index -- a measure of height to weight that's tied to disease risk. A BMI of 25 and above is considered overweight; 30 and above, obese. A person who is 5-foot-8 is overweight at 165 pounds and obese at 195.
Next spring, the cancer society and Weight Watchers will again offer weigh-ins and programs to increase awareness during the second Great American Weigh In.
"We intend to make next year's Great American Weigh In much bigger and better," says Chris Corcoran, a Weight Watchers spokesperson.
It's scheduled for March 5, but Doyle says the entire week may be devoted to education programs.
Exactly how big a risk excess weight poses was demonstrated dramatically in the New England Journal of Medicine study. Researchers tracked more than 900,000 U.S. adults who were cancer-free in 1982, following them for the next 16 years. They factored in other risk factors to determine what role excess weight played in their cancers.
The researchers concluded there's an association between BMI and death from many forms of cancer, and they identified several forms of the disease not previously linked to unhealthy body weight. These include cancer of the colon, esophagus, gall bladder, kidney, liver, pancreas and rectum, as well as non-Hodgkin's lymphoma and multiple myeloma. For men, there's also an increased risk of prostate and stomach cancer; for women, cancer of the breast, cervix, ovaries and uterus.
One reason excess weight may raise your cancer risk, researchers say, is that fat cells produce a kind of estrogen called estradiol, and this accelerates rapid cell division, in turn increasing cancer risk.
Convincing people to get down to a healthy weight -- as well as stopping smoking, eating a healthy diet, exercising and getting regular checkups -- will produce a dramatic reduction in cancer deaths, Doyle says.
"Close to 65 percent of all cancer deaths could be prevented by lifestyle changes," she says. "I think that's the really good news, that people can have some control over cancer."