Mediterranean diet may reduce cancer risk in people living with obesity

A new study published in JAMA Network Open suggests that closely following a Mediterranean diet may help lower the risk of obesity-related cancers, regardless of body weight.

Researchers found that individuals with high adherence to this diet had a six per cent lower risk of developing certain cancers compared to those with low adherence.

The study analysed data from over 450,000 participants as part of the European Prospective Investigation Into Cancer and Nutrition (EPIC) study. Participants were assessed based on their adherence to the Mediterranean diet, which emphasises whole foods such as fruits, vegetables, legumes, fish, and olive oil while limiting processed foods and red meat.

Researchers found that those who followed the Mediterranean diet closely had a lower incidence of obesity-related cancers, with significant reductions in the risk of colorectal, liver, and kidney cancers. Notably, these benefits were observed independent of body mass index (BMI) and waist-to-hip ratio, suggesting that the protective effects of the diet extend beyond weight management.

Previous studies have highlighted the anti-inflammatory and antioxidant properties of the Mediterranean diet, which may help reduce cancer risk. The diet is rich in fiber, healthy fats, and polyphenols, which support metabolic health, reduce inflammation, and promote a balanced gut microbiome, factors that can influence cancer development.

Interestingly, the study found stronger associations in former and current smokers, suggesting that diet may play a role in mitigating some of the cancer risks associated with smoking. However, researchers did not find a significant link between the Mediterranean diet and reduced risk for postmenopausal breast, endometrial, or ovarian cancer in women.

While these findings reinforce the health benefits of the Mediterranean diet, researchers note some limitations. The study primarily involved European populations, and dietary intake was self-reported, which may introduce bias. Future research should explore biological mechanisms, including the role of inflammation, metabolic health, and gut microbiota, in explaining the protective effects of the diet.

Dr. Anton Bilchik, a surgical oncologist at Providence Saint John’s Cancer Institute, emphasises the importance of dietary choices in cancer prevention: “This study provides further evidence of how a healthy diet, low in processed foods and rich in vegetables, protein, and healthy fats, can reduce the risk of cancer.”

While more research is needed to fully understand the mechanisms at play, this study reinforces the role of nutrition as a critical factor in cancer prevention and overall health.