Mediterranean diet shown to reduce risk of colorectal cancer

The multiple benefits of following a Mediterranean diet have been known for years now, notably its ability to help reduce the risk factors for heart disease as well as curbing weight gain. Other purported benefits include the diet’s ability to help reduce the risk of colorectal cancer.

While we may know what the Mediterranean diet may entail, what aspects of the diet could be truly beneficial when it comes to this debilitating form of cancer?

Well new research, presented at the European Society of Medical Oncology’s 19th World Congress on Gastrointestinal Cancer, has demonstrated which specific aspects of the diet provide the most (and least) benefit.

Researchers from the Tel-Aviv Medical Centre, Israel, used dietary questionnaires for 808 patients aged between 40 and 70 years and undergoing screening or diagnostic colonoscopies, with low risk of colorectal cancer.

Adherence to a Mediterranean diet in this study was defined as higher than average intake of fruits, vegetables and legumes, nuts and seeds, whole grains, fish and poultry, with a high ratio of monounsaturated to saturated fatty acids and a below average consumption of red meat, alcohol and soft drinks.

The basis of this study was to understand specifically which components of the diet, separately and in combination, reduce the risk of developing advanced colorectal polyps.

Colorectal polyps are actually pretty common, affecting 15-20% of the UK population, usually without symptoms. However, around one in 10 of these benign polyps will turn cancerous, known as advanced polyps or adenomas, so therefore the more polyps you develop, they more likely one or more will turn cancerous.

Comparing individuals with polyp-free colonoscopies to those with advanced polyps, a clear association between the Mediterranean diet and colorectal cancer risk was identified. The greater number of components of the diet consumed, the greater the reduction in risk.

For the advanced poly group, the average number of components consumed was 1.9, whereas in the poly-free group it was 4.5 components; even consuming just two or three components, compared to none, resulted in a 50% reduction in advanced polyp risk.

The most important aspects of the diet, the researchers found, were the increased intake of fish and fruit, as well as a low intake of soft drinks. Commenting on these specific findings, co-author Naomi Fliss Isakov, PhD, said: “We found that each one of these three choices was associated with a little more than 30% reduced odds of a person having an advanced, pre-cancerous colorectal lesion, compared to people who did not eat any of the MD components. Among people who made all three healthy choices the benefit was compounded to almost 86% reduced odds.”

If you needed any further reasons to boost your intake of fresh fruit and fish, and to cut down on the fizzy drinks, now might be a good time to start.

Wishing you the best of health,

Dominic Rees
Editorial Health Researcher