— Even medium adherence to the Mediterranean diet was associated with some level of protection
by Kristen Monaco, Senior Staff Writer, MedPage Today
February 25, 2025

The perennial top-ranked Mediterranean diet may help to stave off some obesity-related cancers, data on nearly half a million European adults suggested.

Adjusted analyses showed that people with the greatest adherence to the Mediterranean diet had a modest 6% lower risk for obesity-related cancers compared with those with the lowest adherence (HR 0.94, 95% CI 0.90-0.98), reported Inmaculada Aguilera-Buenosvinos, PhD, of the University of Navarra in Pamplona, Spain, and colleagues.

But as detailed in JAMA Network Open, high adherence was linked with up to a 48% lower risk of site-specific obesity-related cancers:

• Colorectal cancer: HR 0.92 (95% CI 0.85-0.99)
• Hepatocellular carcinoma: HR 0.52 (95% CI 0.33-0.83)
• Kidney cancer: HR 0.67 (95% CI 0.55-0.82)

Medium adherence to the diet was also associated with significantly lower risks for colorectal, kidney, and liver cancers, along with a lower risk of esophageal cancer (HR 0.66, 95% CI 0.48-0.93).

“According to the International Agency for Research on Cancer, excess body weight is convincingly linked to a heightened cancer risk at 13 anatomic sites, including cancers of the endometrium, esophagus, kidney, pancreas, liver, and breast, among others,” Aguilera-Buenosvinos’ group noted. Currently, about 43% of the global adult population and over 70% of U.S. adults have overweight or obesity.

“Adherence to the Mediterranean diet has been linked with reduced central adiposity, lower BMI [body mass index], and less weight gain, supporting our hypothesis that the association between Mediterranean diet adherence and reduced obesity-related cancer risk may be associated with BMI and [waist-to-hip ratio],” they added. However, the protective association between the Mediterranean diet and obesity-related cancers may involve other mechanisms, said Aguilera-Buenosvinos and colleagues, as their results “did not suggest mediation through overweight and obesity.”

They referenced a 2017 study that also used data from the European Prospective Investigation Into Cancer and Nutrition (EPIC) study, where the Mediterranean diet’s protective link with colorectal cancer risk wasn’t mediated by abdominal adiposity.

“The potential benefits of the Mediterranean diet for cancer prevention may be from interactions and synergistic effects among its various components, collectively enhancing health benefits beyond those observed for individual foods alone,” Aguilera-Buenosvinos and co-authors wrote.

They suggested that the cancer protection may be driven by improvements in metabolic and inflammatory markers associated with the Mediterranean diet, such as fasting blood glucose and C-reactive protein. Higher fiber intake may also counteract carcinogenic compounds from processed meats and harmful foods.

Data for the analysis came from the EPIC study, which enrolled participants ages 35 to 70 years from 1992 to 2000 across 23 centers in Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the U.K. The average age of the 450,111 participants included was 51 years, and 29% were men. Average BMI was 25.3 and mean waist-to-hip ratio was 0.8. Adults with cancer at baseline were excluded.