S248 Association Between Dietary Fiber Intake and Colorectal Adenoma: A Systematic Review and Meta-Analysis

Introduction: Colorectal adenoma, a precursor to colorectal cancer, has been studied in relation to dietary fiber consumption; however, the results of the prior studies are inconsistent. Herein, we aim to assess the relationship between dietary fiber consumption and colorectal adenoma risk. Methods: PubMed and Google Scholar were thoroughly searched from inception until May 3, 2023. The studies that reported an association between dietary fiber intake and the incidence of colorectal adenoma were incorporated. A random-effects model was used to produce pooled odds ratios (ORs) with 95% confidence intervals (CIs). Moreover, sub-group analyses were performed, based on study designs (case-control/cross-sectional, and cohort studies) and adenoma site. Results: A total of 23 studies were included. The pooled analysis showed that high dietary fiber intake was associated with a decreased risk of colorectal adenoma (OR: 0.73, 95% CI: 0.66–0.80). Subgroup analysis based on the study’s design revealed similar results in both groups (case-control/cross-sectional = OR: 0.76, 95% CI: 0.69-0.84, cohort = OR: 0.71, 95% CI: 0.59-0.85). Similarly, results from subgroup analysis based on adenoma site were also consistent (rectal adenoma = OR: 0.78, 95% CI: 0.63-0.97, and colon adenoma = OR: 0.80, 95% CI: 0.69-0.93). Conclusion: This meta-analysis demonstrates a strong relationship between dietary fiber consumption and the risk of colorectal adenoma. Increased fiber consumption is associated with a lower incidence of colorectal adenoma, highlighting the possible preventative function of a high-fiber diet. These findings have important public health implications, emphasizing the necessity of maintaining a fiber-rich dietary pattern.Figure 1.: Effect of dietary fiber on risk of colorectal adenoma; subgroup analysis based on study design. Effect of dietary fiber on risk of colorectal adenoma; subgroup analysis based on adenoma site.