The traditional Mediterranean diet (MD) is characterised by a high intake of fruit, vegetables and legumes, whole grains, fish, and monounsaturated fat, moderate alcohol intake and low intake of refined grains, red meat, and sweets. The MD can protect against heart disease, as has been shown in previous studies.
It has also been suggested that eating a MD may also protect against cancer, and may have a stronger effect on cancer types with a poor prognosis, such as oesophageal, stomach, pancreatic and lung cancer. For these cancer types prevention is of utmost importance, given the very poor prognosis. However, there are still very few studies available on this, and there is no consistent pattern of results available yet, let alone on specific subtypes of these cancers.
Aims and objectives
We investigated whether eating a MD lowered the risk of all cancer in men and women, and specifically the risk of oesophageal, stomach, pancreas, lung, and breast cancer. We also investigated whether the influence of the MD is different for various subtypes of oesophageal, stomach, pancreas, lung, and breast cancers, and whether it is associated more strongly with smoking-related cancers.
We tested whether specific dietary components of the MD have a dominant influence of the observed associations with cancer.
Finally, we compared the MD with World Cancer Research Fund’s Recommendations to see which prevented cancer more.
How the study was done
We looked at 120,852 men and women aged 55–69 years who completed a self-administered questionnaire on dietary habits and other risk factors for cancer.
After 20 years of follow-up, we observed 32,249 new cases of cancer. The full original (1986) questionnaires of these subjects were entered into our database, and from that the average intake of nutrients and foods was calculated.
A score was constructed that indicates adherence to the MD. In the statistical analyses, we assessed the association of MD adherence with the occurrence of cancer after 20 years.
Eating a MD was associated with a reduced overall cancer risk in women, but not in men.
It was also associated with a reduced risk of oestrogen receptor (ER) negative, postmenopausal breast cancer, reduced risk of lung cancer, reduced risk of oesophageal squamous cell carcinoma (men only), gastric cardia adenocarcinoma, and gastric non-cardia adenocarcinoma.
However, eating a MD was associated with a significantly increased risk of non-advanced prostate cancer.
> Mediterranean diet adherence and risk of pancreatic cancer: a pooled analysis of two Dutch cohorts
> Adherence to the Mediterranean diet and risk of lung cancer in the Netherlands Cohort Study
> Mediterranean diet adherence and risk of post-menopausal breast cancer: results of a cohort study and meta-analysis