Matheus Souza, Marcio J M Amaral, Luan C V Lima
Higher adherence to healthy PBDs is associated with lower risks of MASLD and liver cancer, while unhealthy PBDs have the opposite pattern of association. Although the evidence base is observational and causality cannot be inferred, these findings support further investigation of nutrient-rich, minimally processed plant foods in hepatology and public health.
BACKGROUND AND AIMS: The impact of plant-based dietary patterns on liver-related outcomes, including metabolic dysfunction-associated steatotic liver disease (MASLD) and liver cancer, remains uncertain and has not been systematically assessed. We aimed to evaluate the association between plant-based diet (PBD) indices and the risk of MASLD and liver cancer in adult individuals through a systematic review and meta-analysis.
METHODS: We searched PubMed and Embase databases from 2016 to October 31, 2025, for observational studies examining the associations of the plant-based diet index (PDI), healthy PDI (hPDI), or unhealthy PDI (uPDI) with MASLD and/or liver cancer. Study-level data were extracted using a standardized form. Adjusted odds ratios (aORs) or adjusted hazard ratios (aHRs) were pooled using random-effect meta-analysis.
RESULTS: Thirteen studies (∼1.2 million adults) were included. In non-longitudinal studies, higher adherence to PDI and hPDI was associated with lower odds of prevalent MASLD (PDI: aOR = 0.85, 95% confidence interval [CI]: 0.74 to 0.96; hPDI: aOR = 0.76, 95% CI: 0.71 to 0.80), whereas higher uPDI was associated with greater odds (aOR = 1.32, 95% CI: 1.21 to 1.43). In longitudinal studies, higher adherence to PDI and hPDI was associated with a reduced risk of incident MASLD (PDI: aHR = 0.82, 95% CI: 0.70 to 0.95; hPDI: aHR = 0.70, 95% CI: 0.62 to 0.79), while higher uPDI increased risk (aHR = 1.24, 95% CI: 1.10 to 1.40). Higher adherence to PDI and hPDI was associated with a lower risk of liver cancer (PDI: aHR = 0.78, 95% CI: 0.67 to 0.92; hPDI: aHR = 0.71, 95% CI: 0.60 to 0.84), whereas higher uPDI increased risk (aHR = 1.34, 95% CI: 1.04 to 1.73). Heterogeneity was low to moderate.
CONCLUSIONS: Higher adherence to healthy PBDs is associated with lower risks of MASLD and liver cancer, while unhealthy PBDs have the opposite pattern of association. Although the evidence base is observational and causality cannot be inferred, these findings support further investigation of nutrient-rich, minimally processed plant foods in hepatology and public health.