Mediterranean Diet May Cut Risk for Obesity-Related Cancers

TOPLINE:

Greater adherence to the Mediterranean diet was associated with a modest reduction in the risk for obesity-related cancers, particularly hepatocellular, kidney, and colorectal cancers, a new analysis found. The analysis also revealed that this association was independent of body mass index (BMI) and waist-to-hip ratio.

METHODOLOGY:

• The Mediterranean diet has been linked to a range of health benefits, including reduced risks for several cancers, but evidence on its association with obesity-related cancer risk and whether levels of excess body fat mediate that risk remain limited.
• Researchers analyzed data from 450,111 participants (mean age, 51.1 years; 70.8% women) in the EPIC study, which included individuals from 23 centers in 10 countries.
• The researchers assessed diet using validated country-specific questionnaires, focusing on 14 food groups and nutrients, including vegetables, legumes, fruits, nuts and seeds, dairy products, cereals, meat and meat products, fish and seafood, and various types of fats.
• Adherence to the Mediterranean diet was scored on a 9-point scale and categorized as low (0-3 points), medium (4-6 points), or high (7-9 points). The median follow-up duration was 14.9 years.
• The primary study outcome was the incidence of obesity-related cancers.

TAKEAWAY:

• Overall, 4.9% of the participants developed obesity-related cancers. The incidence rates were 0.053 per person-year in the low adherence group, 0.049 per person-year in the medium group, and 0.043 per person-year in the high adherence group.
• Participants with high adherence to the Mediterranean diet had a lower risk for obesity-related cancers than those with low adherence (hazard ratio [HR], 0.94; 95% CI, 0.90-0.98). A similar trend was observed in participants with medium vs low adherence (HR, 0.96; 95% CI, 0.94-1.00).
• Site-specific analysis showed higher adherence to the Mediterranean diet was associated with lower risks for colorectal (HR, 0.92), hepatocellular (HR, 0.52), and kidney cancers (HR, 0.67). Medium adherence to the Mediterranean diet was associated with a lower risk for esophageal cancer (HR, 0.66).
• The protective effect of the Mediterranean diet was not mediated by BMI or waist-to-hip ratio.

IN PRACTICE:

“The findings of this cohort study indicate that higher adherence to the [Mediterranean diet] may slightly reduce the risk of [obesity-related cancers],” the authors wrote, adding that “even a medium adherence was associated with a small reduction in the risk of these specific cancers.”

“Although our results did not suggest mediation through overweight and obesity, more studies are needed to better understand the mechanisms through which higher adherence to the [Mediterranean diet] might potentially reduce cancer risk,” the authors said.

SOURCE:

The study, led by Inmaculada Aguilera-Buenosvinos, PhD, Department of Preventive Medicine and Public Health, University of Navarra in Pamplona, Spain, was published online on February 25 in JAMA Network Open.

LIMITATIONS:

The study relied on data taken only at baseline, potentially missing changes over time. The Mediterranean diet adherence score may not fully capture the complexity of dietary patterns, particularly in non-Mediterranean populations. Additionally, self-reported anthropometric data, including weight, height, and waist and hip circumferences information, for some participants could have introduced bias.

DISCLOSURES:

The study received support through grants from the Instituto de Salud Carlos III and the Wellcome Trust. Additional support came from various national organizations across participating countries, including the Danish Cancer Society, Ligue Contre le Cancer, German Cancer Aid, and others. One author reported receiving grants from the Health Research Fund–Instituto de Salud Carlos III during the conduct of the study.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.