Mediterranean Diet Linked to Lower Risk for Stomach Cancer

Laurie Barclay, MD

December 29, 2009

December 29, 2009 — Greater adherence to a relative Mediterranean diet is associated with a significantly lower risk for incident gastric adenocarcinoma, according to the results of a prospective cohort study reported online in the December 9 issue of the American Journal of Clinical Nutrition.

"The Mediterranean dietary pattern is believed to protect against cancer, although evidence from cohort studies that have examined particular cancer sites is limited," write Genevieve Buckland, BS, from the Catalan Institute of Oncology, Idibell, in Barcelona, Spain, and colleagues from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study.

The goal of this study was to evaluate the association between adherence to a relative Mediterranean diet and incident gastric adenocarcinoma. The study cohort consisted of 485,044 participants from 10 European countries who provided dietary and lifestyle information at recruitment into EPIC. Age range was 35 to 70 years, and 144,577 subjects were men. An 18-unit relative Mediterranean diet score, which included information regarding 9 key components of the Mediterranean diet, allowed estimation of relative Mediterranean diet adherence.

The investigators evaluated the association between a relative Mediterranean diet and gastric adenocarcinoma with respect to anatomic location (cardia and noncardia) and histologic types (diffuse and intestinal). To control for dietary measurement error, they performed a calibration study in a subsample.

During mean follow-up of 8.9 years, there were 449 validated cases of incident gastric adenocarcinoma that could be analyzed. Compared with low relative Mediterranean diet adherence, high adherence was associated with a significant decrease in gastric adenocarcinoma risk (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.47 - 0.94), after stratification by center and age and after adjustment for known cancer risk factors.

For every 1-unit increase in relative Mediterranean diet score, the risk for gastric adenocarcinoma decreased by 5% to 7% (95% CI, 0.91 - 0.99). Different anatomic locations and histologic types showed no evidence of heterogeneity. Trends were similar for the calibrated results (overall HR for gastric adenocarcinoma, 0.93; 95% CI, 0.89 - 0.99).

"Greater adherence to an rMED [relative Mediterranean diet] is associated with a significant reduction in the risk of incident GC [gastric adenocarcinoma]," the study authors write. "To our knowledge, this is the first study to evaluate the Mediterranean diet and GC."

Limitations of this study include possible errors in measuring dietary intake, possible residual confounding, lack of information on intake of legumes in Norway and olive oil in Umea, and limitations of the Mediterranean diet score. In addition, some participants may have modified their diet during the early prediagnostic period of the disease.

"The results add to the evidence for the role of the Mediterranean diet in reducing cancer risk and add further support for the need to continue to promote the Mediterranean diet in areas where it is disappearing," the study authors conclude. "Moreover, the 5-y relative survival rate of GC is very poor (23%), and the prognosis may be even worse for cardia GC, the incidence of which is increasing in Europe. Therefore, identifying dietary recommendations that can help reduce incidence is important for the effective management of this cancer."

The European Commission supported this study. The EPIC study was funded by the "Europe Against Cancer" Programme of the European Commission; ISCIII of the Spanish Ministry of Health; Ligue contre le Cancer (France); Société 3M (France); Mutuelle Générale de l'Education Nationale; Institut National de la Santé et de la Recherche Médicale (INSERM); German Cancer Aid; German Cancer Research Center; German Federal Ministry of Education and Research; Danish Cancer Society; Health Research Fund (FIS) of the Spanish Ministry of Health; the participating regional governments and institutions of Spain; Cancer Research United Kingdom; Medical Research Council, United Kingdom; the Stroke Association, United Kingdom; British Heart Foundation; Department of Health, United Kingdom; Food Standards Agency, United Kingdom; the Wellcome Trust, United Kingdom; the Greek Ministry of Health; the Stavros Niarchos Foundation; Hellenic Health Foundation; Italian Association for Research on Cancer; Dutch Ministry of Health, Welfare and Sports; Dutch Ministry of Health; Dutch Prevention Funds; LK Research Funds; Dutch Zorg Onderzoek Nederland; World Cancer Research Fund; Swedish Cancer Society; Swedish Scientific Council; Regional Government of Skane, Sweden; and the Norwegian Cancer Society. Some of the study authors are partners of ECNIS, a network of excellence of the EC.

Am J Clin Nutr. Published online December 9, 2009. Abstract