Dairy Product Consumption and Colorectal Cancer Prevention: An updated Meta-Analysis of Observational Studies from 2020-2025

Abstract

Background: Colorectal cancer (CRC) is the third most common cancer worldwide and a leading cause of cancer-related mortality. Dietary factors, particularly dairy consumption, have been implicated in CRC prevention. This updated systematic review analyzed recent observational studies (2020–2025) to evaluate the association between dairy intake and CRC risk reduction. Methods: A systematic literature search was conducted across PubMed, Embase, Google Scholar, and Web of Science. The inclusion criteria encompassed cohort and case-control studies assessing dairy product consumption and its protective impact on CRC incidence. The quality of the studies was assessed using the ROBINS-I Scale. Meta-analysis was performed using a random- effects model, and heterogeneity was evaluated using Cochran’s Q-test and the I² statistic. Results: From an initial 571 studies, 12 met the inclusion criteria, comprising 821,865 participants (813703 from cohort studies and 8,162 from case-control studies). Overall, dairy consumption was associated with a 25% reduced CRC risk (OR: -0.25, 95% CI: -0.33 to -0.17, I² = 87.1%,

p < 0.0001). Cohort studies demonstrated an 11% risk reduction (RR: 0.89, 95% CI: 0.85–0.94, I² = 68.2%) when dairy products are used by the population for a longer time (9 years to 25 years). While, case-control studies reported a 52% reduction (OR: 0.48, 95% CI: 0.35–0.65, I²

= 87.9%) in severity and mortality among newly diagnosed CRC patients. Subgroup analysis

indicated a 26% risk reduction in CRC incidence by using total dairy products and a 28% reduction by using milk.

Conclusion: This systematic review underscores the potential for dairy-based dietary interventions in CRC prevention, with milk being the most protective agent against CRC. Further randomized controlled trials are warranted to confirm these associations.