A large cohort study has found that higher adherence to the Mediterranean diet may be linked to a modest reduction in the risk of obesity-related cancers, independent of body mass index and waist-to-hip ratio.
In the study, published in JAMA Network Open, investigators analyzed the data from 450,111 individuals who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
The multicenter, prospective EPIC study involved participants aged 35 to 70 years across ten European countries between 1992 and 2000. The investigators categorized Mediterranean diet (MedDiet) adherence into low, medium, and high groups based on dietary assessments at recruitment. The primary outcome of the study was obesity-related cancer (ORC) incidence, classified using International Agency for Research on Cancer criteria.
The investigators observed a 6% lower ORC risk (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.90–0.98) among those with high MedDiet adherence (7 to 9 points) compared with those with low adherence (0 to 3 points). Incidence rates per person-year were 0.053, 0.049, and 0.043 among the low, medium, and high adherence groups, respectively. The strongest inverse associations were seen for colorectal cancer (HR = 0.92), hepatocellular carcinoma (HR = 0.52), and renal cancer (HR = 0.67), while no statistically significant associations were found for hormone-related cancers.
Further analysis confirmed that the association between MedDiet adherence and ORC risk was independent of body mass index and waist-to-hip ratio. Sensitivity analyses using an alternative MedDiet scoring system (HR = 0.93, 95% CI = 0.89–0.98) and excluding alcohol from the score (HR = 0.94, 95% CI = 0.90–0.99, P = .06) yielded similar results. Stratified analyses found the protective effects were more pronounced among those who smoked, with high MedDiet adherence linked to a 14% lower ORC risk (HR = 0.86, 95% CI = 0.80–0.94).
"Intervention studies have also shown that the MedDiet is positively associated with metabolic and inflammatory markers such as fasting blood glucose and C-reactive protein," said lead study author Inmaculada Aguilera-Buenosvinos, PhD, of the Department of Preventive Medicine and Public Health at the University of Navarra in Pamplona, Spain, and colleagues.
Study limitations included reliance on baseline dietary assessments and self-reported anthropometric data. The investigators emphasized the need for future studies incorporating repeated dietary measurements and objective adiposity markers.
The findings aligned with prior research on dietary patterns and cancer prevention, suggesting MedDiet benefits may extend beyond weight management. Further research is needed to explore underlying mechanisms.
Full disclosures are detailed in the study.