The role of nutritional interventions on cancer incidence and mortality: A systematic review of randomized controlled trials

: Cancer remains a leading cause of morbidity and mortality worldwide. Nutrition plays a crucial role in modulating cancer risk. Numerous studies suggesting dietary factors can influence cancer development and progression. The present review aimed to clarify the evidence from randomized controlled trials (RCTs) on the effects of specific dietary factors and nutritional interventions on cancer incidence and mortality. Methods: The present systematic review was executed according to the PRISMA protocol. A search was conducted on the Persian (SID, Magiran) and English (PubMed, EMBASE, Web of Science, Google Scholar, Scopus) databases from ۲۰۰۰ to June ۱۰, ۲۰۲۴. Inclusion criteria were RCTs that investigated the effects of dietary interventions on cancer incidence and/or progression. After searching all databases, ۲۲۵۰ articles were identified at this stage. The screening process of articles was conducted by three-reviewers respectively. After title, abstract or full-text reading and applying exclusion criteria, we reviewed ۴۵ studies on the nutritional interventions on cancer incidence and mortality. Results: A total of ۴۵ RCTs met the inclusion criteria, including over ۵۰,۰۰۰ participants in the intervention and control groups. According to the studies, nutritional interventions varied widely, including supplementation with vitamins (e.g., vitamin D, vitamin C), minerals (e.g., selenium), dietary patterns (e.g., Mediterranean diet, low-fat diet), and specific foods (e.g., fruits, vegetables, whole grains). Thirty-eight studies demonstrated a significant reduction in cancer incidence and biomarkers of cancer risk with specific dietary interventions. For example, high-fiber diets and increased consumption of fruits and vegetables were consistently associated with lower risk of colorectal cancer. Conclusion: According to the findings, nutritional interventions and cancer incidence and mortality are significant associations and several studies have proven the effect of nutritional interventions on cancer incidence and mortality. However, the heterogeneity in study designs and outcomes highlights the need for more standardized and long-term RCTs to establish definitive dietary recommendations for cancer prevention. Future research should focus on elucidating the mechanisms by which nutrition impacts cancer biology and identifying population subgroups that may benefit most from specific dietary strategies.

کلیدواژه ها:

Cancer prevention ، nutrition ، dietary interventions