By John Tyburski, Nature World Report, Posted March 16 2015
According to the American Cancer Society, colon cancer is the third most common non-skin cancer diagnosed in the U.S. It is the second leading cause of cancer-related death in men and women, showing up in over 93,000 people each year. The lifetime risk for developing colon cancer is about one in 20. While the causes of colon cancer remain mysteries, many have speculated that diet plays a key role. New evidence suggests that diet and nutrition may be the best things to consider when reducing the risk of colon cancer.
Researchers at Loma Linda University in California examined dietary data gathered from over 77,000 men and women who identify as Seventh-Day Adventists and are enrolled in the Adventist Health Study (AHS-2), a large, prospective cohort study of more than 96,000 North Americans recruited between January 1, 2002, and December 31, 2007. The diets of the participants were assessed using a validated quantitative food frequency questionnaire and categorized in each of four vegetarian diet schemes: vegan, lacto-ovo (milk-eggs) vegetarian, pescovegetarian (fish-eating), semivegetarian (some meat). Results from individuals with these dietary patterns were compared to those having non-vegetarian dietary habits.
When assessing the relationship between dietary patterns and new cases of colon and rectum cancers in the study population, the researchers found that pescovegetarians had a 43 percent lower risk of developing cancers of the colon and rectum. The next best diet for reducing risk was the lacto-ovo vegetarian with an 18 percent lower risk. Vegans exhibited a 16 percent risk reduction, and semivegetarians experienced only an 8 percent risk reduction.
“Vegetarian diets are associated with an overall lower incidence of colorectal cancers,” wrote the scientists in a study report published in JAMA Internal Medicine. “Pescovegetarians in particular have a much lower risk compared with nonvegetarians. If such associations are causal, they may be important for primary prevention of colorectal cancers.”