Being overweight or obese significantly increased the risk of developing at least 13 types of cancer, according to a report by the Centers for Disease Control and Prevention.
Now that a larger proportion of the American population is overweight or obese, the rates of obesity-related cancers have increased. Between 2005 and 2014, the rate of obesity-related cancers, excluding colorectal cancer, increased by seven percent. Over the same period, non-obesity-related cancers declined.
The researchers examined the United States Cancer Statistics data set, which includes data from the National Program of Cancer Registries and the Surveillance, Epidemiology and End Results program.
They found that 631,604 people were diagnosed with an overweight- or obesity-related cancer, 40 percent of nearly 1.6 million of all cancer diagnoses in 2014. The effect was more pronounced in older people (age at least 50 years), compared with younger people, with two-thirds of cases occurring in the 50- to 74-year-old age range.
Women were much more likely to have over-weight- and obesity-related cancers, with higher incidence rates (218.1 per 100,000 population) than those of men (115.0 per 100,000). A contributing factor for this difference between men and women was female-specific cancers such as endometrial, ovarian, and postmenopausal breast cancers, which accounted for 42 percent (268,091) of overweight and obesity-related cancers.
Researchers found that, between 2005 and 2014, the overall incidence of overweight-and obesity-related cancers (including colorectal cancer) decreased by two percent, colorectal cancer decreased by 23 percent and cancers unrelated to body weight decreased by 13 percent. A contributing factor to the decrease in colorectal cancer was most likely cancer screening tests, which can detect and lead to the removal of precancerous polyps.
“A majority of American adults weigh more than recommended – and being overweight or obese puts people at higher risk for a number of cancers – so these findings are a cause for concern,” a CDC director said in a statement. “By getting to and keeping a healthy weight, we all can play a role in a cancer prevention.”