Plant-based diets linked to reduced gastrointestinal cancer risk, systematic review finds

A systematic review of dietary patterns has unveiled a compelling association between vegetarian diets and a reduced risk of gastrointestinal tumorigenesis. This study, which encompassed data from various observational research, offers promising evidence that embracing a vegetarian diet may be associated with a lower risk of gastrointestinal cancer.

Researchers conducted an extensive search of medical databases including PubMed, Embase, Cochrane Library, and Web of Science, spanning from the inception of these databases to August 2022. The systematic review incorporated data from eight original studies, comprising seven cohort studies and one case-control study, and involved a substantial cohort of 686,691 participants.

Key findings from the meta-analysis revealed a noteworthy association between vegetarian diets and a reduced risk of gastrointestinal tumorigenesis. Moreover, subgroup analysis provided additional insights. Vegetarian diets were found to be particularly effective in lowering the risk of specific gastrointestinal cancers, including gastric cancer and colorectal cancer . However, there was no significant correlation with upper gastrointestinal cancer (excluding the stomach).

Furthermore, gender and regional variations were observed. The study indicated that vegetarian diets were strongly associated with reduced gastrointestinal tumorigenesis risk in men but showed a weaker correlation in women. Regional differences were also noted, with North American and Asian populations experiencing significant risk reduction, while the European population showed weaker correlations.

Reference: Bai, Tongtonga; Peng, Juanjuanb; Zhu, Xinqic; Wu, Chengyua. Vegetarian diets and the risk of gastrointestinal cancers: a meta-analysis of observational studies. European Journal of Gastroenterology & Hepatology 35(11): 1244-1252, November 2023. | DOI: 10.1097/MEG.0000000000002643