Adherence to the Mediterranean Diet and Obesity-Linked Cancer Risk in EPIC
Authors: Aguilera-Buenosvinos Inmaculada , Morales Berstein Fernanda , González-Gil Esther M. , Dossus Laure , Gunter Marc J. , Biessy Carine , Masala Giovanna , Santucci De Magistris Maria , Laouali Nasser , Shah Sanam , Marques Chloé , Heath Alicia K. , Tsilidis Konstantinos K. , Cross Amanda J. , Ferrari Pietro , Castro-Espin Carlota , Debras Charlotte , Tumino Rosario , Tjønneland Anne , Halkjær Jytte , Drake Isabel , Ericson Ulrika , Guevara Marcela , Rodríguez-Barranco Miguel , Skeie Guri , Braaten Tonje , Gram Inger Torhild , Dahm Christina C. , Agnoli Claudia , Schulze Matthias B. , Huerta José María , Martínez-González Miguel Ángel , Huybrechts Inge , Toledo Atucha Estefania 
Published: February 2025

ImportanceAdherence to the Mediterranean Diet (MedDiet) has been associated with a lower incidence of cancer and reduced weight gain. These associations suggest a potential role for the MedDiet in lowering the risk of obesity-related cancers (ORCs). Obesity is a known risk factor for various cancers and shows an inverse association with MedDiet adherence.ObjectiveTo examine the association between adherence to the MedDiet and the risk of ORCs, considering the possible mediating role of adiposity.Design, Setting, and ParticipantsThis prospective cohort study analyzed data from the European Prospective Investigation Into Cancer and Nutrition (EPIC) study, which enrolled participants aged 35 to 70 years from 1992 to 2000 across 23 centers in 10 countries. The data analysis was conducted from March 1 to May 31, 2023.ExposuresDietary intake before baseline was evaluated using country-specific, validated questionnaires administered at recruitment. Adherence to the MedDiet was scored on a 9-point scale and categorized as low (0-3 points), medium (4-6 points), or high (7-9 points).Main Outcomes and MeasuresThe primary outcome was the incidence of ORCs, classified according to the 2015 International Agency for Research on Cancer criteria. Multivariable Cox proportional hazards regression models were used to assess the association between MedDiet adherence and ORC incidence. Mediation analyses were conducted to evaluate the role of waist to hip ratio and body mass index in this association.ResultsA total of 450 111 participants were included in the study (mean [SD] age, 51.1 [9.8] years; 70.8% women) and followed up during a median (IQR) time of 14.9 (4.1) years. Among participants, 4.9% experienced an ORC (rates, 0.053, 0.049, and 0.043 per person-year in the low, medium, and high MedDiet adherence groups, respectively). Participants with high adherence to the MedDiet (7-9 points) had a lower risk of ORC compared with those with low adherence (0-3 points) (hazard ratio [HR], 0.94; 95% CI, 0.90-0.98). A similar inverse association was observed for participants with medium adherence (4-6 points vs 0-3 points). However, mediation analyses did not show associations of waist to hip ratio or body mass index between MedDiet adherence and ORC risk.Conclusions and RelevanceThese findings indicate that higher adherence to the MedDiet is associated with a modest reduction in the risk of ORCs, independent of adiposity measures. Further research is needed to clarify the mechanisms by which the MedDiet may contribute to cancer prevention.