The decline in deaths from all cancers combined continued in the USA from 2004-2008, but a major government report highlights a worrisome rise in cases linked to obesity and inactivity.
Although the overall rate of new cancer cases is declining, the report confirms research showing that excess weight and a sedentary lifestyle are risk factors for one-quarter to one-third of common cancers in the USA. About one-third of adults — almost 78 million — are obese, roughly 30 or more pounds over a healthy weight.
“I don’t think Americans understand the association between cancer and obesity,” says physician Marcus Plescia, director of the division of cancer prevention for the Centers for Disease Control and Prevention. “We do know people are afraid of cancer. They know about the links (from obesity) to diabetes, heart disease and arthritis, but many don’t know about this. They need to know.”
The report, published Wednesday in the journal Cancer, is co-authored by researchers from the CDC, the North American Association of Central Cancer Registries, theNational Cancer Institute and the American Cancer Society.
For people who do not smoke, maintaining a healthy weight and getting sufficient exercise may be among the most important ways to prevent cancer, the authors write. The risk factors are second only to tobacco as preventable causes of disease and death in the USA.
“Education (campaigns) about the risks associated with smoking have been successful,” says Plescia. He adds that this year’s report documents the second straight year of decreasing lung cancer death rates among women. “This is an important trend. We hope to spread the same important message about obesity.”
In addition to contributing to cancer risk, obesity adversely affects quality of life for cancer survivors and may worsen prognosis for several cancers, the authors write.
The American Cancer Society estimates that one-third of the more than 572,000 cancer deaths in the USA each year can be attributed to diet and physical activity habits, including overweight and obesity, while another third are caused by exposure to tobacco products.