IMPACT OF PLANT-BASED DIETARY PATTERNS ON OBESITY-RELATED CANCERS: THE SEGUIMIENTO UNIVERSITY OF NAVARRA (SUN) PROSPECTIVE COHORT

ABSTRACT Evidence suggests that plant-based dietary patterns —favoring plant-based foods without being strictly vegetarian or vegan — may prevent obesity and offer health benefits. Since not all plant-based foods are equally healthy, it is essential to distinguish between healthful and unhealthful plant-based options. Objective: This study aimed to analyze the associations between different plant-based dietary patterns and the incidence of obesity-related cancers. We followed-up 16,256 participants from the “Seguimiento Universidad de Navarra” (SUN) prospective cohort. Based on a validated food frequency questionnaire, we calculated adapted overall, healthful and unhealthful plant-based diet index scores. Scores for were assessed at baseline and repeatedly after 10 years of follow-up. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated using multivariable-adjusted time-dependent Cox models. After a median follow-up of 13 years, 221 incident obesity-related cancer cases were confirmed. Overall plant-based and unhealthful plant-based dietary patterns showed no association. Contrarily, participants in the highest tertile of the healthful plant-based diet score had a lower obesity-related cancer risk (HR T3vsT1 0.67; 95% CI, 0.47 -0.97; P trend =0.031). This association persisted after updating dietary information at 10-year follow-up (HR T3vsT1 0.68; 95% CI, 0.47 -0.99; P trend =0.037) and was stronger for women (HR T3vsT1 0.52; 95% CI, 0.32 -0.86; p interaction = 0.04). In this large prospective cohort, greater alignment with a healthful plant-based dietary pattern was associated with a decreased risk of obesity-related cancer, whereas alignment with overall and unhealthful plant-based dietary patterns showed no association.