40 percent of cancers are related to being overweight, says study

October 7, 2017 1:00 PM

Obesity-related cancers of the liver, stomach, and pancreas are rising.

Packing on the pounds isn’t just bad for your heart—it could also raise your risk of developing cancer.

In fact, 40 percent of all cancers are linked to being overweight or obese, according to a new report from the Centers for Disease Control and Prevention (CDC).

In the study, researchers crunched the numbers from the United States Cancer Statistics for 2014 to assess incidence rates, and the data from 2005 to 2014 to analyze the trends. They discovered that of the nearly 1.6 million cancers diagnosed in 2014, about 630,000 of them were of cancers that are linked to being overweight or obese.

The International Agency for Research on Cancer (IARC) says that 13 cancers are associated with being overweight or obese: esophagus; cancers of the breast (in postmenopausal women), colon and rectum, endometrium, gallbladder, stomach, kidney, liver, ovary, pancreas, and thyroid, as well as meningioma (cancer of the membranes surrounding the brain and spinal cord) and multiple myeloma, a cancer of the blood cells.

What’s more, rates for some of the obesity-related cancers, like of the thyroid, liver, stomach, pancreas, and kidney, rose each year.

That means 4 out of every 10 cancers diagnosed each year can be linked to being overweight or obese. And that’s a problem, considering that 71 percent of all American adults can be considered overweight or obese, according to the CDC.

The exact reason for the relationship between obesity and cancer isn’t certain. And researchers can't say for sure whether having too much fat actually causes the cancer. But there is a physiological mechanism that may be at play: Researchers believe that too much extra fat triggers the production of inflammatory compounds in your body, which can set the stage for cancer development. It can also increase your levels of the hormone insulin, which can raise your risk, too.

Bottom line: Staying at a healthy weight can protect your entire body. But if you’re already carrying a few too many extra pounds, you may not have to lose as much as you think.

Losing as little as five percent of your body weight can help reduce your cancer risk, Graham Colditz, M.D., chair of the IARC Working Group, told us in the past.