Researchers found that people who inherit a variation of a gene called ADIPOQ, which results in the formation of a fat hormone called adiponectin, are 30 percent less likely to develop colon cancer.
People identified without this gene variant, or who have excessive blood levels of the fat hormone, would therefore benefit from early colon examinations, said Boris Pasche, professor at the University of Alabama Comprehensive Cancer Center and lead author of the study.
"Our hope is that we can significantly improve the screening and early detection for this disease, and open new avenues for better understanding the genetic and lifestyle factors that influence colon cancer risk," said Pasche.
A third of people with colon cancer have a family history of the disease, he said.
Scientists have already proven a link between obesity and genetics, and that colon cancer is influenced by genetics.
The latest study, published in the Journal of the American Medical Association, is the first to prove a three-way connection between genetics, obesity and colon cancer risk.
The study showed that test subjects who did not have the genetic variation could reduce their risk through physical exercise and dieting to lose weight.
Colon cancer is the third deadliest cancer in the United States.
Nearly 150,000 Americans are diagnosed each year, and 50,000 of those diagnosed die from the disease, according to estimates from the American Cancer Society.