FRIDAY, June 5, 2009 (HealthDay News) -- It's been known for some time that obesity and eating lots of red meat can raise the risk of colorectal cancer, but new research sheds light on other lifestyle factors that increase risk.
Drinking alcohol, smoking cigarettes and having diabetes also play a major role in determining who is going to develop colorectal cancer, study findings show.
And although exercise seemed to help ward off colorectal cancer, eating lots of fruits and vegetables didn't, according to researchers at The George Institute for International Health in Australia.
"Most people probably know that being overweight and having poor dietary habits are risk factors for the disease," said study author Rachel Huxley, an associate professor at The George Institute. "But most are probably unaware that other lifestyle risk factors such as alcohol consumption, cigarette smoking and diabetes are also important culprits," she said in a news release from the institute.
Not counting skin cancers, colorectal cancer is the third most common cancer among U.S. adults, according to the American Cancer Society. An estimated 50,000 people will die of colorectal cancer this year in the United States.
Worldwide, about one million new cases of colorectal cancer are diagnosed annually and more than half a million people die, according to background information in the news release.
In the new study, Huxley and colleagues reviewed more than 100 published reports linking colorectal cancer and modifiable risk factors such as alcohol, smoking, diabetes, physical activity and diet.
The researchers found that people who consumed more than seven drinks a week had a 60 percent greater risk of developing the cancer compared to non-drinkers.
Smoking, obesity and diabetes were also associated with a 20 percent greater risk of developing colorectal cancer, about the same risk as consuming high intakes of red and processed meat, they noted.
The study also found that physical activity lowered the risk of the disease but there was little evidence that high intakes of fruit and vegetables were protective against colorectal cancer.
"These findings strongly suggest that a large proportion of colorectal cancer cases could potentially be avoided by making relatively modest lifestyle adjustments such as drinking less, quitting smoking, eating healthily and being a little more active," Huxley said. "Such changes would also have huge benefits in terms of reducing an individuals' risk of developing other major forms of illness including cardiovascular disease."
The American Cancer Society has more on colorectal cancer.