PT - JOURNAL ARTICLE AU - Michael Stoneham AU - Michael Goldacre AU - Valerie Seagroatt AU - Leicester Gill TI - Olive oil, diet and colorectal cancer: an ecological study and a hypothesis AID - 10.1136/jech.54.10.756 DP - 2000 Oct 01 TA - Journal of Epidemiology and Community Health PG - 756--760 VI - 54 IP - 10 4099 - http://jech.bmj.com/content/54/10/756.short 4100 - http://jech.bmj.com/content/54/10/756.full SO - J Epidemiol Community Health2000 Oct 01; 54 AB - STUDY OBJECTIVES Colorectal cancer (CRC) is a common cancer in many western countries and is probably caused in part by dietary factors. Southern European countries have lower incidence rates of CRC than many other western countries. It was postulated that, because olive oil is thought to influence bile salt secretion patterns in rats, it may influence the occurrence of CRC. The purpose of this study was to compare national levels of dietary factors, with particular reference to olive oil, with national differences in CRC incidence. DESIGN Ecological study using existing international databases. Incidence rates for CRC, food supply data, and olive oil consumption data were extracted from published sources, combined, and analysed to calculate the correlations between CRC and 10 dietary factors. Associations were then explored using stepwise multiple regression. SETTING 28 countries from four continents. MAIN RESULTS 76% of the intercountry variation in CRC incidence rates was explained by three significant dietary factors—meat, fish and olive oil—in combination. Meat and fish were positively associated, and olive oil was negatively associated, with CRC incidence. CONCLUSION Olive oil may have a protective effect on the development of CRC. The proposed hypothesis is that olive oil may influence secondary bile acid patterns in the colon that, in turn, might influence polyamine metabolism in colonic enterocytes in ways that reduce progression from normal mucosa to adenoma and carcinoma.