Coffee consumption and risk of colorectal cancer in a population‐based prospective cohort of Japanese men and women

Abstract

We prospectively examined the association between coffee consumption and the risk of developing colorectal cancer in a large population-based cohort study (the JPHC Study) of Japanese men and women. Data were analyzed from a population-based cohort of 96,162 subjects (46,023 men and 50,139 women). A total of 1,163 incident colorectal cancers were identified during the followup period, including 763 cases of colon cancer and 400 of rectal cancer. We observed a significant inverse association between coffee consumption and the risk of developing invasive colon cancer among women. Compared with those who almost never consumed coffee, women who regularly consumed 3 or more cups of coffee per day had a RR of 0.44 (95% CI 5 0.19-1.04; p for trend 5 0.04) after adjustment for potential confounding factors. However, no significant association was found for rectal cancer in women. In men, no significant decrease was observed in any colorectal cancer site. Further, additional analyses on the association of green tea consumption with colorectal cancer risk found no significant association in men or women. These findings suggest that coffee consumption may lower the risk of colon cancer among Japanese women. ' 2007 Wiley-Liss, Inc.Key words: colorectal cancer; coffee; prospective study; Japan Colorectal cancer is one of the most common cancers in more developed countries, with nearly 945,000 new cases diagnosed worldwide each year and 492,000 deaths. 1 In Japan, the incidence and mortality of colorectal cancer has recently increased, and it is now a leading cause of morbidity and mortality, with about 36,000 deaths in 2000.2 This recent increase in Japan may be associated with changes in environmental factors such as dietary habits or lifestyle factors.Coffee drinking is popular in many parts of the world. In Japan, coffee has been popularly consumed since its initial introduction, although coffee consumption is relatively new in comparison to green tea consumption. Given the widespread consumption of coffee and high incidence of colorectal cancer in developed countries, the possible role of coffee consumption in the etiology of colorectal carcinogenesis has drawn interest, 3 and the relation between coffee consumption and colorectal cancer risk has been investigated over the last 4 decades. However, results from epidemiological studies have been inconsistent.3,4 A meta-analysis showed a lower risk of colorectal cancer associated with substantial consumption of coffee, 3 but the results were inconclusive owing to inconsistencies between case-control and prospective studies. Case-control studies have tended to support an inverse association between coffee consumption and risk of colorectal cancer, [5][6][7][8][9][10][11][12][13][14][15] whereas the albeit limited number of prospective cohort studies have not supported any significant reduction in risk. [16][17][18][19][20][21][22][23][24][25] Moreover, most previous studies have been conducted in Western countries. 16-24Here, we prospectively examined the association between...

Coffee consumption and risk of colorectal cancer: a meta-analysis of observational studies

“…If the study sample was found to overlap with that in another article or if two articles described aspects of the same study, only the publication with the largest sample was used (10)(11)(12)(13)(14)(15)(16)(17)(18) . If a study provided several OR/RR, we extracted the one reflecting the greatest degree of control for potential confounders (17,(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29) . To assess a summary OR/RR for colorectal cancer in both sexes, we used combined estimates if provided.…”

Cancer Chemoprevention by Dietary Polyphenols

“…The first consisted of 96,162 Japanese men and women, and 1163 incident cases of colorectal cancer [111]. There was no statistically significant association between green tea consumption and incidence of colon and rectal cancers combined or separately in either men or women or both.…”

“…There were two recent prospective studies on green tea consumption and colorectal cancer incidence and mortality in Japan [111,112]. The first consisted of 96,162 Japanese men and women, and 1163 incident cases of colorectal cancer [111].…”

Food Factors and Oxidative DNA Damage / DNA Repair Systems

“…However, its effects on human health are not well understood. Some studies suggested that coffee consumption had preventive properties for metabolic diseases, such as type 2 diabetes [40,41], or cancers, such as hepatocellular carcinoma [42,43] and colorectal cancer [44,45], through its content of potentially antimutagenic substances [46]. These findings led to the hypothesis that coffee consumption lowers the risk of some types of cancers.…”