Coffee consumption and colorectal cancer risk: a multicentre case-control study from Italy and Spain.

BACKGROUND: Coffee contains many bioactive substances that can play a role on colorectal cancer. Epidemiological evidence of coffee intake and colorectal cancer is, however, inconsistent. AIM: To provide further information on the risk of colorectal cancer in relation to coffee consumption. METHODS: Data derive from two companion case-control studies conducted in Italy and Spain within the European Union Project on Health Impacts of long-term exposure to disinfection by-products in Drinking Water and the Spanish Multi-Case Control study on Cancer. These included a total of 2289 incident cases with colorectal cancer and 3995 controls with information on coffee intake. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived from unconditional logistic regression models, adjusted for study centre, sex, age, education, smoking, and other covariates. RESULTS: Compared with never coffee drinkers, the OR was 0.99 (95% CI 0.95-1.02) for total coffee consumption. There was no significant trend in risk with dose or duration, the ORs being 0.95 (95% CI 0.72-1.25) for an amount of five or more cups per day of coffee and 0.95 (95% CI 0.75-1.19) for a duration of consumption of 50 years or longer. The OR was 1.04 (95% CI 0.87-1.25) for two or more cups per day of decaffeinated coffee. There were no heterogeneity across strata of various covariates, as well as no apparent differences between various anatomical subsites. CONCLUSION: This large pooled analysis of two studies shows no association of coffee and decaffeinated coffee with colorectal cancer risk.

Allium vegetable intake and gastric cancer: a case-control study and meta-analysis.

SCOPE: To provide new epidemiological data and summarize evidence on the association between allium vegetable intake and gastric cancer risk. METHODS AND RESULTS: Data were from an Italian case-control study including 230 cases and 547 controls. Odds ratios were derived using multiple logistic regression. We combined results from all published studies using random-effect models. In our case-control study, the odds ratios were 0.59 (95% confidence interval, CI, 0.25-1.41) for ≥2 portions of onion per week, 0.69 (95% CI, 0.41-1.15) for high garlic intake, and 0.70 (95% CI, 0.39-1.28) for frequent use of both onion and garlic. Besides our study, 22 case-control and four cohort studies were included in the meta-analyses (>10 000 cases). The pooled relative risks for the highest versus lowest intake category were 0.78 (95% CI, 0.67-0.91) for allium vegetables (ten case-control and four cohort studies), 0.60 (95% CI, 0.47-0.76) for garlic (12 case-control studies), and 0.55 (95% CI, 0.41-0.73) for onion (13 case-control studies). The pooled relative risk for high allium vegetable intake from the four cohorts was 1.02 (95% CI, 0.88-1.18). CONCLUSION: High allium vegetable consumption is likely to reduce gastric cancer risk. This evidence is derived mainly from case-control studies. Further data from large cohorts are desirable for conclusive confirmation.

Gastric cancer and allium vegetable intake: a critical review of the experimental and epidemiologic evidence.

There are suggestions of an anticancerogenic effect of allium vegetables and their associated organosulfur components against several cancer types, including gastric cancer, but the issue remains open to discussion and quantification. The present critical review discussed the history, the health properties, the chemistry, the anticancerogenic evidences from experimental studies, and the anticancer mechanisms of allium vegetables. We also summarized findings from epidemiological studies concerning the association between different types of allium vegetables and gastric cancer risk, published up to date. Available data, derived mainly from case-control studies, suggested a favorable role of high intakes of allium vegetables, mainly garlic and onion, in the etiology of gastric cancer. In particular, of 10 studies, 7 suggested a favorable role of high intake of total allium vegetables and gastric cancer. All 14 studies on garlic and most studies on onion (more than 80%) reported a beneficial role of these allium types against gastric cancer. However several limitations, including possible publication bias and the difficulty to establish a dose-risk relationship, suggest caution in the interpretation. Evidences on other types of allium vegetables, as well as on the influence of different gastric cancer anatomical and histological types, are less consistent.