A vegetarian diet reduced the risk of colorectal cancer, according to an analysis of a large, prospective study.
Among 77,659 participants in the Adventist Health Study 2, pescovegetarians (ate fish but not other meats) had the lowest adjusted risk of colorectal cancer, with a hazard ratio of 0.57, compared with nonvegetarians, according to Dr. Michael J. Orlich of Loma Linda (Calif.) University and his associates.
For vegans, the hazard ratio was 0.84; for lacto-ovo vegetarians (consumed eggs/dairy), the hazard ratio was 0.82; and for semivegetarians (ate meat less than once a week), the hazard ratio was 0.92. Only the difference between pescovegetarians and nonvegetarians was statistically significant.
The adjusted hazard ratio for all vegetarians was 0.78, a significant difference. There were no significant differences between men or women, or between ethnicities.
Although the increased benefit that pescovegetarians saw likely stems from long chain fatty acid consumption, “analysis may elucidate whether the reduced risk seen in the pescovegetarian group is attributable to fish consumption or to other aspects of the diet,” the investigators said.
Find the full study in JAMA Internal Medicine (doi:10.1001/jamainternmed.2015.59).