UICC World Cancer Congress 2006

Objective:The purpose of this study is to clarify whether lifestyle can modify the effects of radiation exposure on cancer risk. Numerous laboratory and animal studies have described the protective effects of dietary factors supplemented before radiation exposure, examining their radio-protective effects. However, human studies are very limited and little is known about the lifestyle effects after radiation exposure on radiation damage and cancer risks.

Methods:A cohort of about 40,000 atomic-bomb survivors of Hiroshima and Nagasaki, for whom radiation dose estimates were currently available, had their lifestyle (smoking, drinking, diet, etc) assessed in 1980. They were followed during 20 years for incidence of cancer. The combined effect of smoking, drinking, diet and radiation exposure on cancer risk was examined in additive and multiplicative models.

Results:Preliminary results show that the combined effects of a diet rich in fruit and vegetables and ionizing radiation exposure result in a lower cancer risk as compared to those with a diet poor in fruit and vegetables and exposed to radiation. Similarly, those exposed to radiation and who never drink alcohol or never smoke tobacco present a lower oesophagus cancer risk than those exposed to radiation and who currently drink alcohol or smoke tobacco. There is no evidence to reject either the additive or the multiplicative model.