Coffee and cancer : a review of epidemiological studies, 1990–1999

We report on the associations between the intake of certain foods and beverages and the incidence of gastric cancer in a cohort of 11,907 randomly selected Japanese residents of Hawaii (6297 women and 5610 men). The daily intake of six beverages, cigarettes and alcohol and the weekly frequency of intake of 13 foods and food groups was estimated with a short food frequency questionnaire. Over an average follow-up period of 14.8 years, 108 cases of gastric cancer (44 women, 64 men) were identified via linkage to the Hawaii Tumor Registry. In gender-combined proportional hazards analyses, the consumption of fresh fruit seven or more times per week was associated with a significantly reduced risk of gastric cancer, compared to lower levels of consumption (relative hazard (RH): 0.6, 95% confidence interval (CI): 0.4-1.0, P = 0.03). The combined intake of fresh fruit and raw vegetables was inversely associated with the risk of gastric cancer in the total cohort, and among the men (P < 0.05). No significant relationships were found between gastric cancer incidence and the intake of pickled vegetables, miso soup, dried or salted fish, or processed meats among either gender. Compared to non-drinkers, men who drank one cup of coffee per day had a significantly elevated risk of gastric cancer (RH: 2.5, 95% CI: 1.0-6.1, P = 0.05), but there was no evidence of a dose-response relationship. Cigarette smoking and consumption of alcohol were not related to gastric cancer, in analyses restricted to the men. The results related to fruit and vegetable intake are consistent with an anti-nitrosating effect of these foods, while the unexpected association between coffee consumption and gastric cancer is difficult to explain and may represent a chance finding.

During a 4-year period from January 1995 to December 1998, blood samples and questionnaire data were obtained from 333 incident cases of hepatocellular carcinoma (HCC), as well as from 360 controls who were hospitalized for eye, ear, nose, throat or orthopedic conditions in Athens, Greece. Coded sera were tested for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV) by third-generation enzyme immunoassays, and information on smoking habits and beverage consumption was obtained. We found a significant dose-response, positive association between smoking and HCC risk [>/= 2 packs per day, odds ratio (OR)=2.5]. This association was stronger in individuals without chronic infection with either HBV or HCV (>/= 2 packs per day, OR=2.8). Consumption of alcoholic beverages above a threshold of 40 glasses per week increased the risk of HCC (OR=1.9). We also found evidence of a strong, statistically significant and apparently super-multiplicative effect of heavy smoking and heavy drinking in the development of HCC (OR for both exposures=9.6). This interaction was particularly evident among individuals without either HBsAg or anti-HCV (OR for both exposures=10.9). Coffee intake was not positively associated with HCC risk, but the reverse could not be excluded for the subgroup of chronically infected individuals. In conclusion, tobacco smoking and heavy alcohol consumption are associated with increased risk of HCC, especially when these 2 exposures occur together. Copyright 2000 Wiley-Liss, Inc.

Relationships between coffee drinking and cancer incidence were examined in a 10-year complete follow-up of 21,735 men and 21,238 women aged 35-54 years. The study population participated in a cardiovascular screening in three countries in Norway during 1977-82. Data on coffee and smoking habits were based on information from a self-administered questionnaire. There was no association between coffee consumption and overall risk of cancer. A positive association was found between coffee drinking and risk of lung cancer, also after adjustment for age, cigarette smoking, and county of residence. Residual confounding by cigarette smoking and other lifestyle factors cannot be ruled out. A negative association was found with cancer of buccal cavity and pharynx and with malignant melanoma in women. No significant associations were found between coffee drinking and incidence of cancer of the pancreas or the bladder.