Exercising regularly is one of the five healthy lifestyle factors that decrease risk of colorectal cancer.
Researchers from the German Institute of Human Nutrition Potsdam-Rehbrueck in Nuthetal - who examined data on hundreds of thousands of men and women - estimate that 22% of the men and 11% of the women who developed colorectal cancer would not have developed the disease if they had adopted all five of the healthy lifestyle behaviors.
They report their study in the journal BMC Medicine.
The five healthy lifestyle factors are: keeping to a healthy weight, not carrying a lot of fat around the belly, exercising regularly, not smoking, limiting alcohol intake and having a healthy diet.
A healthy diet is defined as one that is low in red and processed meat and rich in fruits, vegetables, nuts, seeds, yogurt and foods high in fiber.
'The healthier the lifestyle, the better'
Lead author Dr. Krasimira Aleksandrova, of the Institute's Department of Epidemiology, says:
"These data provide additional incentive to individuals, medical professionals and public health authorities to invest in healthy lifestyle initiatives. Each person can contribute a lot to avoid cancer, the more healthy lifestyle changes, the better."
Globally, colorectal cancer, also known as bowel cancer, is the second most common cancer in men and the third most common in women. Previous studies have found links between higher rates of this cancer and Western lifestyles. 55% of cases occur in developed nations such as those of North America and Western Europe.
But while many studies have found links between the individual five healthy lifestyle behaviors and incidence of colorectal cancer, this is the first large study to look at what their combined effect might be.
Dr. Aleksandrova and colleagues analyzed data on 347,237 men and women who took part in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which covered 10 European countries. Over 12 years of the study, 3,759 of the participants developed colorectal cancer.
Following all five healthy behaviors linked to lowest risk of colorectal cancer
The EPIC study recorded details of participants' lifestyles, allowing the team to analyze the data using a "healthy lifestyle index," which awarded one point to each participant for each of the five healthy behaviors. Thus, each participant in the study was assigned an index between 0 and 5, depending on how many of the healthy lifestyle behaviors they followed.
The researchers found the more healthy lifestyle factors participants adopted, the lower their risk of developing the disease. The ones who scored the maximum five points - that is, they followed all five of the healthy behaviors - had the lowest risk of developing colorectal cancer.
"Our data confirmed that with an increasing number of healthy lifestyle behaviors the risk that a person will have of developing bowel cancer decreases," says Dr. Aleksandrova.
She and her colleagues found that compared with people who followed only one of the healthy behaviors, those who followed two, three, four or all five had a 13%, 21%, 34% and 37% lower risk of developing colorectal cancer, respectively.
They also found a difference between men and women, as Dr. Aleksandrova explains:
"Estimates based on our study populations suggest that up to 22% of the cases in men and 11% of the cases in women would have been prevented if all five of the healthy lifestyle behaviors had been followed. Our results particularly demonstrate the potential for prevention in men who are at a higher risk of bowel cancer than women."
Despite progress in developing treatments for colorectal cancer, it remains one of the most deadly cancers worldwide. The main cause of death is spread of disease to other organs such as the liver and the lungs, so there is keen interest in finding ways to spot the disease earlier, before it gets to this stage.
Medical News Today recently learned of two new potential biomarkers for the early detection of colorectal cancer that may lead to swifter diagnosis of the disease.