WEDNESDAY, May 24, 2017 (HealthDay News) -- Where you carry extra fat may be as key to your cancer risk as how much extra fat you carry, new research suggests.
The study revealed that too much fat around the waist is as good an indicator of obesity-related cancer risk as body mass index (BMI), which is an estimate of body fat based on weight and height.
"Our findings show that both BMI and where body fat is carried on the body can be good indicators of obesity-related cancer risk," said study lead author Heinz Freisling, a scientist at the International Agency for Research on Cancer.
"To better reflect the underlying biology at play, we think it's important to study more than just BMI when looking at cancer risk. And our research adds further understanding to how people's body shape could increase their risk," Freisling said in a Cancer Research UK news release.
In the study, the researchers analyzed data from about 43,000 people who were followed for an average of 12 years, and from more than 1,600 people who were diagnosed with an obesity-related cancer.
An extra 4.3 inches on the waistline increased the risk of obesity-related cancers by 13 percent, and an extra 3.1 inches on the hips was associated with a 15 percent increased risk, according to the study. But the findings did not prove that excess fat around the middle causes cancer risk to rise.
The findings were published May 24 in the British Journal of Cancer.
After smoking, being overweight or obese is the single biggest preventable cause of cancer and is associated with 13 types of cancer, including bowel, breast and pancreatic, the researchers noted.
Julie Sharp, Cancer Research UK's head of health information, said, "This study further highlights that however you measure it, being overweight or obese can increase the risk of developing certain cancers," including breast and bowel cancer.
"It's important that people are informed about ways to reduce their risk of cancer. And while there are no guarantees against the disease, keeping a healthy weight can help you stack the odds in your favor and has lots of other benefits, too," Sharp said.
"Making small changes in eating, drinking and keeping physically active that you can stick with in the long term can help you get to a healthy weight -- and stay there," she added.
The U.S. National Cancer Institute has more on obesity and cancer.