Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2023 Nov 1;35(11):1244-1252.
doi: 10.1097/MEG.0000000000002643. Epub 2023 Sep 18.

Vegetarian diets and the risk of gastrointestinal cancers: a meta-analysis of observational studies

Tongtong Bai  1 , Juanjuan Peng  2 , Xinqi Zhu  3 , Chengyu Wu  1
Affiliations
Meta-Analysis

Vegetarian diets and the risk of gastrointestinal cancers: a meta-analysis of observational studies

Tongtong Bai et al. Eur J Gastroenterol Hepatol. .

Abstract

The systematic review aimed to assess the association between vegetarian diet and the risk of gastrointestinal tumorigenesis. PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to August 2022 for observational studies on vegetarian diets and the risk of gastrointestinal tumorigenesis. The primary outcome was morbidity due to gastrointestinal cancer. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Pooled effects were analyzed using a random-effects model. The study protocol was registered in PROSPERO (no. CRD42022310187). Eight original studies (seven cohorts and one case-control), involving 686 691 participants, were included. Meta-analysis showed a negative correlation between vegetarian diets and gastrointestinal tumorigenesis risk [relative risk (RR) equals 0.77, 95% confidence interval (CI) is (0.65-0.90)], compared with non-vegetarian diets. Subgroup analysis indicated that vegetarian diets were negatively correlated with the risks of gastric cancer [RR = 0.41, 95% CI (0.28-0.61)] and colorectal cancer [RR = 0.85, 95% CI (0.76-0.95)], but not with that of upper gastrointestinal cancer (excluding stomach) [RR = 0.93, 95% CI (0.61-1.42)]. Vegetarian diets were negatively correlated with the risk of gastrointestinal tumorigenesis in men [RR = 0.57, 95% CI (0.36-0.91)], but were uncorrelated in women [RR = 0.89, 95% CI (0.71-1.11)]. Vegetarian diets were negatively correlated with the risk of gastrointestinal tumorigenesis in North American [RR = 0.76, 95% CI (0.61-0.95)] and Asian populations [RR = 0.43, 95% CI (0.26-0.72)] and were uncorrelated in the European population [RR = 0.83, 95% CI (0.68-1.01)]. Adhering to vegetarian diets reduces the risk of gastrointestinal tumorigenesis. More data from well-conducted cohort and other studies are needed.

PubMed Disclaimer

Conflict of interest statement

There are no conflicts of interest.

Figures

Fig. 1.
Fig. 1.
Flowchart of study selection.
Fig. 2.
Fig. 2.
Forest plot (random-effect model) of the correlation between vegetarian diets with gastrointestinal cancer.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Arnold M, Abnet CC, Neale RE, Vignat J, Giovannucci EL, McGlynn KA, et al. . Global burden of 5 major types of gastrointestinal cancer. Gastroenterology 2020; 159:335–349.e15. - PMC - PubMed
    1. Wu S, Powers S, Zhu W, Hannun YA. Substantial contribution of extrinsic risk factors to cancer development. Nature 2016; 529:43–47. - PMC - PubMed
    1. Solans M, Chan DSM, Mitrou P, Norat T, Romaguera D. A systematic review and meta-analysis of the 2007 WCRF/AICR score in relation to cancer-related health outcomes. Ann Oncol 2020; 31:352–368. - PubMed
    1. Shams-White MM, Brockton NT, Mitrou P, Romaguera D, Brown S, Bender A, et al. . Operationalizing the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations: a standardized scoring system. Nutrients 2019; 11:1572. - PMC - PubMed
    1. Siegel RL, Jemal A, Wender RC, Gansler T, Ma J, Brawley OW. An assessment of progress in cancer control. CA Cancer J Clin 2018; 68:329–339. - PubMed

Publication types