COFFEE AND GALLSTONE DISEASE
The gallbladder stores bile which is a fluid released into the small intestine where it emulsifies fats thus assisting their digestion. Almost 90 percent of gallstones are composed of solid cholesterol and the remainder consist of solid bilirubin, a pigment. Patients with symptomatic gallstones experience severe abdominal pain. However, about 80 percent of people who have gallstones have no symptoms. Gallstones are usually diagnosed by ultrasound but other procedures such as x-rays may also be used. Risk factors for gallstones include age and obesity.
Three cross sectional studies using ultrasound documented gallbladder disease as an endpoint were unable to show any significant associations with coffee consumption in a Danish population (1), pregnant Irish women (2) or German blood donors (3). Although a fourth cross sectional study from the USA could not show any significant associations between coffee consumption and total or previously undiagnosed gallbladder disease, there was a significant inverse association with previously diagnosed gallbladder disease in women although not in men (4).
Two small hospital- based case control studies from Greece (5) and Italy (6) were unable to demonstrate any significant associations between coffee consumption and symptomatic gallbladder disease. By contrast, a large population- based case- control study from Italy showed a significant inverse association between coffee consumption and ultrasound-documented gallstones (7).
Two out of the three published prospective cohort studies showed a protective effect of coffee against the development of gallstones. A large study of college alumni in the USA was unable to show any significant association between coffee consumption and clinical gallbladder disease (8). By contrast, a publication from the Health Professionals Follow-up Study on 46,008 men diagnosed 1,081 new cases of ultrasound documented gallbladder disease and found that men who drank 4 or more cups of coffee per day were 45% less likely to develop the disease (9). Similarly, a publication from the Nurses Health Study on 80,898 women identified 7,811 cholecystectomies and found that women who drank 4 or more cups of caffeinated coffee per day were 28% less likely to have their gallbladder removed (10). The associations were statistically significant in both cohorts.
It can be concluded that the results of the better quality prospective cohort studies suggest that coffee consumption protects against gallstone disease in men and women although the degree of protection may be less in women.
References:
1. Jorgensen, T. et al. Gut, 30, 528-534, 1989.
2. Basso, L. et al. European Journal of Epidemiology, 8, 629-633, 1992.
3. Kratzer, W. et al. Scandinavian Journal of Gastroenterology, 32, 953-958, 1997.
4. Ruhl, C.E. and Everhart, J.E. American Journal of Epidemiology, 152, 1034-1038, 2000.
5. Pastides, H. et al. Archives of Internal Medicine, 150, 1409-1412, 1990.
6. La Vecchia, C. et al. International Journal of Epidemiology, 20, 209-215, 1991.
7. Misciagna, G. et al. European Journal of Gastroenterology and Hepatology, 8, 585-593, 1996.
8. Sahi, T. et al. American Journal of Epidemiology, 147, 644-651, 1998.
9. Leitzmann, M.F. et al. Journal of the American Medical Association, 281, 2106-2112, 1999.
10. Leitzmann, M.F. et al. Gastroenterology, 123, 1823-1830, 2002.