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
. 2021 Apr 15;18(8):4168.
doi: 10.3390/ijerph18084168.

Association between Dietary Fibre Intake and Colorectal Adenoma: A Systematic Review and Meta-Analysis

Daniele Nucci  1 , Cristina Fatigoni  2 , Tania Salvatori  2 , Mariateresa Nardi  1 , Stefano Realdon  3 , Vincenza Gianfredi  4   5
Affiliations
Meta-Analysis

Association between Dietary Fibre Intake and Colorectal Adenoma: A Systematic Review and Meta-Analysis

Daniele Nucci et al. Int J Environ Res Public Health. .

Abstract

PubMed/Medline, Excerpta Medica dataBASE (EMBASE) and Scopus were searched in January 2021 in order to retrieve evidence assessing the association between dietary fibre intake and the risk of colorectal adenoma in adults. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for the reporting of results. Only primary observational studies were included. Publication bias was estimated through the Egger's test and the visual inspection of the funnel plot. Heterogeneity between studies was calculated with I2 statistics. The search strategy identified 683 papers, 21 of which were included in our meta-analysis. Having evaluated a total of 157,725 subjects, the results suggest a protective effect of dietary fibre intake against colorectal adenoma. Effect Size (ES) was [0.71 (95% CI = 0.68-0.75), p = 0.000)]. Moderate statistical heterogeneity (Chi2 = 61.68, df = 23, I2 = 62.71%, p = 0.000) was found. Findings show a statistically significant (p = 0.000) and robust association between a higher intake of dietary fibre and a lower risk of colorectal adenoma, considering both the prevalent and incident risk. Moreover, the meta-regression analysis showed a borderline significant negative linear correlation between the amount of dietary fibre intake and colorectal adenoma. Lastly, we performed a subgroup analysis by sex, showing a higher protective effect for men.

Keywords: adenoma; colorectal; diet; fibre; systematic review.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Flow diagram of the studies’ selection process.
Figure 2
Figure 2
(a) Forest plot and (b) Funnel plot (after trim and fill method) of the meta-analysis comparing dietary fibre intake (lower vs higher intake) and risk of colorectal adenoma (random effect model). In (a) squares represent the effect size values of the individual studies. In (b) white dots represent single studies included. The black dots represent estimated studies after the trim and fill method. The white diamond represents the overall effect size of the included studies. The black diamond represents the estimated overall effect size after the trim and fill method.
Figure 3
Figure 3
Meta-regression plot for (a) fixed effect model and (b) random effect model.
Figure 3
Figure 3
Meta-regression plot for (a) fixed effect model and (b) random effect model.
Figure 4
Figure 4
Forest plot of the cumulative analysis by (a) year of publication (from the first to the most recent published study), (b) by sample size (from the smallest to the largest), (c) dietary fibre dose (from the lowest to the highest intake) between dietary fibre intake and risk of colorectal adenoma. Diamonds represent the effect size estimated using the cumulative analysis calculated adding one study at a time.
Figure 4
Figure 4
Forest plot of the cumulative analysis by (a) year of publication (from the first to the most recent published study), (b) by sample size (from the smallest to the largest), (c) dietary fibre dose (from the lowest to the highest intake) between dietary fibre intake and risk of colorectal adenoma. Diamonds represent the effect size estimated using the cumulative analysis calculated adding one study at a time.
Figure 4
Figure 4
Forest plot of the cumulative analysis by (a) year of publication (from the first to the most recent published study), (b) by sample size (from the smallest to the largest), (c) dietary fibre dose (from the lowest to the highest intake) between dietary fibre intake and risk of colorectal adenoma. Diamonds represent the effect size estimated using the cumulative analysis calculated adding one study at a time.
See this image and copyright information in PMC

References

    1. International Agency for Research on Cancer . In: World Cancer Report: Cancer Research for Cancer Prevention. Wild C.P., Weiderpass E., Stewart B.W., editors. International Agency for Research on Cancer (IARC); Lyon, France: 2020.
    1. Schreuders E.H., Ruco A., Rabeneck L., Schoen R.E., Sung J.J., Young G.P., Kuipers E.J. Colorectal cancer screening: A global overview of existing programmes. Gut. 2015;64:1637–1649. doi: 10.1136/gutjnl-2014-309086. - DOI - PubMed
    1. Centres for Diseases Control and Prevention Colorectal Cancer Screening Tests. [(accessed on 20 February 2021)]; Available online: https://www.cdc.gov/cancer/colorectal/basic_info/screening/tests.htm.
    1. Fleming M., Ravula S., Tatishchev S.F., Wang H.L. Colorectal carcinoma: Pathologic aspects. J. Gastrointest Oncol. 2012;3:153–173. doi: 10.3978/j.issn.2078-6891.2012.030. - DOI - PMC - PubMed
    1. World Cancer Research Fund Diet, Nutrition, Physical Activity and Colorectal Cancer. [(accessed on 13 March 2021)]; Available online: https://www.wcrf.org/sites/default/files/Colorectal-cancer-report.pdf.