Obesity Strongly Linked to Cancer Death
Heaviest Men, Women More Than 50% More Likely to Die of Cancer
WebMD News Archive
April 23, 2003 -- A major new study from the American Cancer Society offers the strongest evidence yet that being overweight increases your risk of dying from cancer. Researchers suggest that as many as 90,000 cancer deaths in the U.S. each year may be related to obesity and could be prevented.
The cancer deaths were not confined to malignancies with known links to excess body weight, such as breast and colorectal cancers. The study identified many cancers not previously associated with obesity, including stomach cancer and prostate cancer in men, multiple myeloma, non-Hodgkin's lymphoma, and cancers of the cervix, ovary, prostate, liver, and pancreas.
"There is no question that this research shifts our thinking about the relationship between overweight and obesity to cancer mortality in general," lead researcher Eugenia E. Calle, PhD, tells WebMD. "Most people don't understand that being overweight or obese is a risk factor for cancer, so we hope it will increase that awareness." Calle directs the analytic epidemiology program at the American Cancer Society (ACS).
The research is published in the April 24 issue of The New England Journal of Medicine. Calle and American Cancer Society colleagues identified 57,145 cancer deaths among 900,000 people followed for 16 years. None of the participants had cancer when they enrolled in the study.
Researchers found that 14% of all cancer deaths among men and 20% of all cancer deaths in women were associated with being overweight or obese. For almost all cancers, the risk of death increased as body mass did. The heaviest men and women in the study were 52% and 62% more likely to die of cancer, respectively, than men and women of normal weight.
The researchers concluded that 90,000 cancer deaths a year in the U.S. are related to excess body weight and could be prevented if people maintained a normal body weight throughout their lifetime. That compares with 170,000 annual deaths attributed to smoking.
"It seems quite clear now that after tobacco smoking, obesity is emerging as the second quantitatively most important cause of cancer, at least in western populations," epidemiologist Hans-Olov Adami, MD, tells WebMD. "This is yet another very important reason for people to keep their weight under control."
Adami, who wrote an editorial accompanying the study, admits he is not optimistic that the new evidence will greatly affect behavior. He is professor and chairman of the department of medical epidemiology and biostatistics at the Karolinska Institute in Stockholm, Sweden.
"We know that there is an epidemic of obesity in the United States, and it is a growing problem throughout the western world," he says. "As long as we make food available in excessive portions on every commercial street corner around the clock and, at the same time, systematically remove all natural incentives to energy expenditure, it is hard to see how this will change."