Excess body fat is associated with an increased risk of 13 types of cancer, and those cancers account for four out of 10 cancers diagnosed in the United States each year, according to a new Vital Signs report from the Centers for Disease Control and Prevention (CDC).
In 2014, about 630,000 Americans were diagnosed with one of these weight-related cancers, the report says.
The CDC researchers also note that although the overall rate of new cancer diagnoses has fallen since the 1990s, diagnoses of cancers associated with being overweight or obese have risen.
“The findings emphasize the importance of intensifying nationwide efforts to prevent and treat overweight and obesity,” the researchers write.
Many Americans unaware of connection
As just about everybody knows by now, the United States — and much of the world — is in the midst of an epidemic of excess weight. About one third of U.S. adults are overweight (defined as a body mass index, or BMI, of 25 to 29.9), and another third are obese (a BMI of 30 or greater).
Yet, surveys have shown that only about half of Americans are aware that excess weight has been linked to an increased risk of cancer.
The new report, which was published Tuesday, is based on data from the United States Cancer Statistics for 2014. The CDC researchers used that data to assess incidence trends from 2005 to 2014 for the 13 cancers for which excess weight is a known risk factor.
Those cancers are meningioma (cancer in the tissue covering the brain and spinal cord), multiple myeloma (a type of blood cancer), adenocarcinoma of the esophagus, postmenopausal breast cancer, and cancers of the colon and rectum, endometrium, gallbladder, upper stomach (gastric cardia), kidney, liver, ovary, pancreas and thyroid.
To be clear, however, although these 13 cancers are more likely to occur in people who are overweight or obese, that doesn’t mean having excess weight causes them. Scientists still do not know what is behind the association.
Here are some of the key findings from the Vital Signs report:
- Weight-related cancers made up 40 percent of the nearly 1.6 million cancers diagnosed in the U.S. in 2014 — 55 percent of the cancers diagnosed in women and 24 percent of the cancers diagnosed in men. The incidence was higher among women in part because endometrial, ovarian and postmenopausal breast cancer account for 42 percent of weight-related cancers.
- Blacks and whites were more likely to be diagnosed with weight-related cancers than other racial or ethnic groups. Black men and American Indian/Alaska Native men, however, had higher rates of the cancers than white men.
- About two out of three of the 630,000 Americans diagnosed with a weight-related cancer in 2014 were aged 50 to 74.
- The incidence of weight-related cancers increased 7 percent between 2005 and 2014, but colorectal (colon and rectum) cancer decreased 23 percent. More widespread screening for colon cancer is the most likely explanation for that cancer’s continued decline, the report says.
- The incidence of cancers not related to excess weight dropped 13 percent between 2005 and 2014.
Take healthful action
“As an oncologist, when people ask me if there’s a cure for cancer, I say, ‘Yes, good health is the best prescription for preventing chronic diseases, including cancer,” said Dr. Lisa Richardson, director of the CDC’s Division of Cancer Prevention and Control, in a released statement. “What that means to health care providers like me is helping people to have the information they need to make healthy choices where they live, work, learn and play.”
Richardson and her CDC colleagues recommend that individuals:
Eat a healthy diet by following the 2015-2020 Dietary Guidelines for Americans.
Do at least 150 minutes of moderate intensity physical activity, such as brisk walking, every week.
Talk to their health care provider about losing weight or maintaining a healthy weight.
Get involved in community efforts to improve options for healthier foods and physical activity.
Lose weight, if they weigh more than recommended, to help reduce risk for some cancers and other chronic diseases.
FMI: The Vital Signs report was published in the Oct. 3 edition of the CDC’s Morbidity and Mortality Weekly Report (MMWR), where it can be read in full.