Lifestyle Changes Can Cut Both Diabetes and Cancer Risk
People with diabetes are at risk of certain cancers, but the exact reason why is still not fully understood. But one thing is known – lifestyle changes that prevent or reverse diabetes will also reduce the risk of cancer.
Diabetes, primarily type 2, doubles the risk of liver, pancreatic, and endometrial cancer. It also increases the risk of colorectal, breast and bladder cancer by 20 to 50%. An expert consensus panel of the American Diabetes Association (ADA) and the American Cancer Society (ACS) met to try to understand why and has written a statement published online in the journal Cancer.
“The full biologic link between diabetes and cancer has not been completely defined,” says panel member Susan M. Gapstur PhD who is the ACS vice president of epidemiology. But there are some clues.
According to Dr. Edward Giovannucci, co-chair of the consensus panel, “Traditionally, there hasn’t been much overlap between research in cancer and diabetes. But recently, it’s become clearer that there are fascinating links between the two.”
People with diabetes tend to have some of the same known risk factors for cancer, including older age, obesity, poor diet, and physical activity. Elevated insulin and glucose levels and inflammation seen in diabetes also increase cancer risk.
"It remains unclear whether the association between diabetes and cancer is direct (e.g., due to hypoglycemia), whether diabetes is a marker of underlying biological factors that alter cancer risk (e.g., insulin resistance and hyperinsulinemia), or whether the association between cancer and diabetes is indirect and due to common risk factors such as obesity," the authors write.
There is also some evidence that diabetes treatments may affect cancer risk. Exogenous insulin, such as the long-acting insulin glargine (Lantus), may increase the risk while Metformin appears to lower the risk of cancer.
"No matter what science ultimately reveals ... we already know what we need to do to lower risk for both cancer and diabetes," Alice Bender, RD, of the American Institute for Cancer Research, says in a news release.
"Eat a healthy, varied, predominantly plant-based diet, be physically active every day, and maintain a healthy body weight. At least for cancer, we know that each factor independently lowers the risk of certain cancers, but all three done together are even more powerful,” she says.
Smoking cessation and moderation in alcohol intake are also an important lifestyle changes to consider reducing risks for both diabetes and cancer.
And those on diabetic treatments should not make decisions based on fear of cancer. “Clearly those being treated for diabetes need to be talking with their doctors about the importance of regular cancer screenings as recommended by the American Cancer Society,” says Dr. Gapstur.
"Diabetes and Cancer: A Consensus Report." Edward Giovannucci, David M. Harlan, Michael C. Archer, Richard M. Bergenstal, Susan M. Gapstur, Laurel A. Habel, Michael Pollak, Judith G. Regensteiner, and Douglas Yee. CA Cancer J Clin, published online before print 16 June 2010.