Vegetarian diet associated with lower risk for colorectal cancer
Click Here to Manage Email Alerts
Vegetarian diets are linked to a lower incidence of colorectal cancer, according to recent study data.
To evaluate whether vegetarian dietary patterns are associated with reductions in colorectal cancer incidence, researchers performed a large, prospective trial between June and October 2014, which involved 77,659 participants recruited to a North American cohort (the Adventist Health Study 2) from January 2002 through December 2007.
Participants completed validated quantitative food frequency questionnaires at baseline and dietary patterns were subsequently categorized as vegan, lacto-ovo vegetarian, pescovegetarian, semivegetarian or nonvegetarian. Demographic and other data was also collected at baseline via questionnaire, and the researchers identified incident colorectal cancers using state cancer registry linkages. To evaluate the relationship between vegetarian dietary patterns and CRC risk, they used Cox proportional hazards regression models controlling for likely confounding factors.
Overall 490 CRC cases (380 colon cancers; 110 rectal cancers) were identified during a mean follow-up period of 7.3 years representing 569,714 total person-years of follow-up. The adjusted hazard ratios compared with nonvegetarians included:
- 0.78 (95% CI, 0.64-0.95) for all CRCs in all vegetarians;
- 0.81 (95% CI, 0.65-1) for colon cancer in all vegetarians;
- 0.71 (95% CI, 0.47-1.06) for rectal cancer in all vegetarians;
- 0.84 (95% CI, 0.59-1.19) for all CRCs in vegans;
- 0.82 (95% CI, 0.65-1.02) for all CRCs in lacto-ovo vegetarians;
- 0.57 (95% CI, 0.4-0.82) for all CRCs in pescovegetarians; and
- 0.92 (95% CI, 0.62-1.37) for all CRCs in semivegetarians.
Effect estimates were comparable between men and women and for black and nonblack individuals.
“We found that vegetarian dietary patterns in a large North American cohort, particularly the pescovegetarian dietary pattern, were associated with lower risk of all [CRC] as well as colon cancer separately,” the researchers concluded. “The evidence that vegetarian diets similar to those of our study participants may be associated with a reduced risk of [CRC], along with prior evidence of the potential reduced risk of obesity, hypertension, diabetes, and mortality, should be considered carefully in making dietary choices and in giving dietary guidance.” – by Adam Leitenberger
Disclosure: Orlich reports he received honoraria from the Northern California Conference of Seventh-Day Adventists and from the Southern California Conference of Seventh-Day Adventists. All other researchers report no relevant financial disclosures.