Regular exercise and a diet rich in fish could help reduce the risk of a relapse for patients who beat colorectal cancer.

The risk of a colorectal cancer relapse doubles in patients who eat fish less than twice a week or get less than 60 minutes of exercise a week, HealthDay reported.

"Once somebody is diagnosed with colon cancer, they may think there is nothing they can do to maintain a healthy lifestyle," Lead author Dr. Mohammed Shaik , a fellow at Michigan State University's Breslin Cancer Center, said HealthDay reported. "We show they can help prevent a recurrence."

To make their findings researchers looked at 1,515 colon cancer patients, 188 of which had suffered a relapse.

"We wanted to know what factors could affect their progression," Shaik said.

Researchers have hypothesized that the omega-three fatty acids found in fish are responsible for these health benefits. It also could have to do with the fact that people who eat fish tend to eat less red meat and processed foods.

"In the United States, there are people who include fish as part of their diet intentionally to be healthier. It's not a standard part of our diet, like it is in other parts of the world," Doctor Smitha Krishnamurthi, an ASCO spokeswoman and an associate professor at Case Western Reserve University School of Medicine in Cleveland, said, HealthDay reported.  

"There's a growing body of epidemiologic evidence that exercise is associated with a reduced risk of recurrent colon cancer," Krishnamurthi said. "It makes sense. For example, we know that exercise reduces insulin levels in the body, and insulin is a growth factor for both normal cells and malignant cells."

Exercise can also reduce inflammation and obesity, which increase the risk of colon cancer.

Smoking tobacco and drinking alcohol were found to have little effect on colon cancer risk.