Abstract
BACKGROUND: An ageing population and an increasing cancer incidence are both public health challenges. Previous literature has established an association between physical activity (PA) and a decreased risk of colorectal cancer (CRC). However, studies pertaining to older adults are limited. OBJECTIVE: This systematic review aims to investigate whether PA prevents CRC in adults aged ≥65 years. The secondary objective is to examine whether CRC risk varies with type, intensity, and/or frequency of PA. METHODS: A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Ovid MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and SPORTDiscus were searched from inception to February 2025. Reference lists of previous studies were also reviewed. Eligible studies included adults aged ≥65 years, assessed the impact of PA on CRC diagnosis, reported empirical outcome data, and were published in English. Studies involving non-human participants or lacking age-specific outcomes were excluded. Methodological quality was assessed using the Mixed Methods Appraisal Tool (MMAT). A narrative synthesis was conducted to analyse the included studies. RESULTS: The search identified 3,604 papers, of which three studies met the inclusion criteria. Overall, there was no consistent association between PA and CRC risk in older adults. One study found no association, a second suggested PA was protective at the highest activity levels, while a third indicated high levels of PA may be harmful. There was also insufficient data to draw any conclusion regarding the secondary outcome. LIMITATIONS: This review was limited by the small number of eligible studies (n = 3) and heterogeneity in activity types and frequency, as well as study durations, which prevented direct comparison. The limited number of studies may reflect the underrepresentation of older adults in research, often due to comorbidities and lower participation rates in this population. Conclusion: Evidence on whether PA prevents CRC in older adults remains inconclusive. Further research focusing on PA type, intensity, and/or frequency is needed to guide age-appropriate public health recommendations.