Religion and reduced cancer risk: what is the explanation? A review.

Several studies of members of Christian religious communities have shown significantly lower risks for certain cancers amongst members than in the general population. We identified 17 epidemiological studies of the risk for cancer amongst members of Christian communities published during the past 40 years. In the studies in which adjustment was made only for age and sex, reductions were observed in the risks for lifestyle-associated cancers, i.e. those associated with tobacco smoking, alcohol consumption, diet, physical activity and reproductive factors. In the studies in which adjustment was also made for healthy habits, no reduction in risk for cancer was observed. We conclude that the most important factor in the correlation between membership in a religious Christian community and risk for cancer is the healthy lifestyle inherent in religious practice in these communities. The epidemiological studies reviewed did not, however, differentiate the effect on cancer risk of the meaning that a certain lifestyle can give to an individual.