Work

The association between dietary fiber intake and risk of lung cancer: a GRADE-assessed systematic review and dose response meta-analysis of prospective cohort studies

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: BACKGROUND: Earlier meta-analyses have examined the relationship between fruit and vegetable intake and risk of lung cancer; however, no study has investigated the link with fiber. Therefore, in the present systematic review and dose-response meta-analysis we aimed to summarize available findings from prospective studies on the link between dietary fiber consumption and lung cancer risk. METHODS: Studies reporting risk estimates for the association between dietary fiber intake and lung cancer risk were included based on a systematic search of PubMed, Scopus, and Web of Science as well as Google Scholar up to 21 April 2025. The Newcastle-Ottawa Scale and GRADE methodology were used to assess the risk of bias and certainty of the evidence, respectively. A random-effects model was used to combine the studies' risk estimates. Dose-response relationships were explored using a one-stage random-effects model. RESULTS: Prospective cohort studies with a total of 2,999,203 participants and 26,012 cases were included. According to linear dose-response analysis, each 5 g/d increase in dietary fiber intake was associated with an 8% reduction in risk of lung cancer (RR: 0.92; 95% CI: 0.85, 0.98). No evidence of a nonlinear relationship between dietary fiber intake and risk of lung cancer was observed (P-nonlinearity = 0.995). The certainty of the evidence was rated as moderate according to the GRADE rating tool. CONCLUSIONS: The findings of this meta-analysis support the protective association between dietary fiber intake and lung cancer risk. However, due to different limitations the results should be interpreted with caution. TRIAL REGISTRATION: PROSPERO registration number: CRD420251037254.

Source: Nutrition Journal

DOI: 10.1186/s12937-026-01337-3

Authors: Kimia Fathzadeh, Shervin Kazeminejad, Arghavan Balali, Leila Azadbakht

Institutions: Tehran University of Medical Sciences, Isfahan University of Medical Sciences, Endocrinology and Metabolism Clinical Sciences Institute, Diabetes Research Center

Language: English

Topic: Nutritional Studies and Diet

Subfield: Public Health, Environmental and Occupational Health

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,190