There is no conclusive evidence that moderate coffee consumption is a risk factor for the development of human cancer. The World Cancer Research Fund published a comprehensive review of diet and cancer in which it stated that `most evidence suggests that regular consumption of coffee and/or tea has no significant relationship with the risk of cancer at any site’ (1).
A large study of almost 43,000 people conducted in Norway, one of the largest consumers of coffee per capita, also found no association between coffee consumption and overall risk of cancer (2).
And a review of results from studies conducted over the past two decades concludes that in doses usually consumed, coffee does not have genotoxic, mutagenic or carcinogenic effects (3).
A large volume of published data clearly shows that drinking coffee is not associated with the development of breast cancer, or fibrocystic or benign breast disease. This includes seven cohort studies conducted in Sweden, Norway and the US studying a combined total of nearly quarter of a million people(4-10).
The UK Case-Control Study Group concurred with previously published studies of older women with breast cancer in finding no effect of smoking, alcohol or caffeine consumption on breast cancer risk in young women (11).
The original suggestion of a link between coffee and pancreatic cancer, in a well-publicised report in the early 1980s (12), was subsequently retracted by the same researchers (13).
Such case control studies on pancreatic cancer are hard to trust as poor survival leads to reduced participation rates by cases in interviews (14). The vast majority of cohort studies show no significant association between coffee consumption and pancreatic cancer (2, 14, 15)
Although a small study has suggested that coffee drinking may be associated with a risk for ovarian cancer (16), a thorough review of the research overall shows there is in fact no real evidence that coffee drinking is a risk factor when known confounding factors are taken into account (17). Latest case control and cohort studies support this (2,18)
Results of studies investigating possible risk of bladder cancer due to coffee drinking have been contradictory. But larger studies have tended to find no associations (5, 19). Confounding factors such as smoking are known to influence results, and it has been noted that these may well be responsible for apparent associations between coffee drinking and bladder cancer (20).
In 2000 a pooled analysis of ten European case control studies of non-smokers found that the risk of bladder cancer in coffee drinkers was no greater than in non-coffee drinkers unless consumption was ten cups or more per day. This is considerably greater than the average consumption in the UK (21).
Although cohort studies have more robust designs than case control studies they have never been separately analysed. The most recently published cohort study found 569 bladder cancer cases in a study population of 3,123 men and women from the Netherlands (22). The association between coffee consumption and bladder cancer was not significant in men and had an inverse association in women.
There is no evidence for any association between drinking coffee and the development of colon or colorectal cancer (23). To the contrary, there is some evidence for a protective effect of coffee against these types of cancer (5, 20, 24, 25).
In the most recently published cohort study there was no association between the risk of colorectal cancer and coffee consumption. (26)
- World Cancer Research Fund. Food, Nutrition and the Prevention of Cancer: a Global Perspective. 1997
- Stensvold I, Jacobsen B.K. Cancer Causes and Control, 5, 401-408, 1994
- Nehig, A. and Debry, G. World review of Nutrition and Diabetes, 79, 185-221, 1996
- Snowden, D.A. and Phillips, R.L. American Journal of Public Health, 74, 820-823, 1984
- Jacobsen, B.K. et al. Journal of the National Cancer Institute, 76, 823-831, 1986
- Vatten, L.J. et al. British Journal of Cancer, 62, 267-270, 1990
- Hunter, D.J. et al. American Journal of Epidemiology, 136, 1000-1001, 1992
- Graham, S. et al. American Journal of Epidemiology, 136, 1327-1337, 1992
- Folsom, A.R. et al. American Journal of Epidemiology, 138, 380-383, 1993
- Michels, K.B. et al. Annals of Epidemiology, 12, 21-26, 2002
- Smith, S.J. et al. British Journal of Cancer, 70, 112-119, 1994
- MacMahon, B. et al. New England Journal of Medicine, 304, 630-633, 1981
- Hseih, C.C. et al. New England Journal of Medicine, 315, 587-589, 1986
- Michaud, D.S. et al. Cancer Epidemiology Biomarkers and Prevention, 10, 429-437, 2001
- Isaksson, B. et al. International Journal of Cancer, 98, 480-482, 2002
- La Vecchia, C. et al. International Journal of Cancer, 33, 559-562, 1984
- Leviton, A. Cancer Letters, 51, 91-101, 1990
- Kuper, H. et al. International Journal of Cancer, 88, 313-318, 2000
- Tavani, A. and La Vecchia, C. European Journal of Cancer Prevention, 9, 241-256, 2000
- World Health Organisation International Agency for Research on Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans – Coffee, Tea, Maté, Methylxanthines and Methyglyoxal, 51, 1991
- Sala, M. et al. Cancer Causes and Control, 11, 925-931, 2000
- Zeegers, M.P.A. et al. Cancer Causes and Control, 12, 231-238, 2001
- Rosenberg, L. et al. Cancer Letters, 52, 163-171, 1990
- Woolcott, C.G. et al. European Journal of Cancer Prevention, 11, 253-263, 2002
- Giovannucci, E. American Journal of Epidemiology, 147, 1043-1052, 1998
- Terry, P. et al. Gut, 49, 87-90, 2001