Coffee Does Not Affect Risk of Colorectal Cancer Among Women and Men
However, largest studies to date find reduction in risk among those who regularly drank decaffeinated coffee
Boston, MA – Frequent consumption of coffee and other caffeinated beverages has been thought to decrease the risk of colon and rectal cancers. However, researchers at Brigham and Women’s Hospital (BWH), in two of the largest studies to date, found that coffee or caffeine did not change the risk for colorectal cancer in women and men. Instead, researchers found that regular consumption of decaffeinated coffee was associated with a reduced incidence of these cancers. These findings are published in the February 16, 2005 issue of the Journal of the National Cancer Institute.
According to lead author Karin B. Michels, ScD, a clinical epidemiologist at BWH and associate professor at Harvard Medical School, “Given how prevalent coffee consumption is around the globe, any effects of caffeine on health could have enormous public health implications. In these two large studies, we find evidence that coffee’s benefits for reducing colorectal cancer seems to be minimal, but instead, decaffeinated coffee consumption might reduce risk of colorectal cancer.”
In two analyses of data from the large prospective cohorts of the Nurses’ Health Study (NHS) and the Health Professionals’ Follow-up Study (HPFS) researchers explored the relation between the consumption of caffeinated and decaffeinated coffee and tea and the incidence of colorectal cancer in these groups. The researchers analyzed the data of 87,794 women from the NHS who were fee of cancer, Crohn’s Disease and ulcerative colitis in 1980 and 46,099 men from the HPFS free of cancer in 1986. Both groups regularly completed a food frequency questionnaire that queried participants on their consumption of coffee and caffeinated tea, cola or other caffeinated sodas and chocolate.
Michels and her colleagues did not find a significant association between consumption of caffeinated coffee and the incidence of colorectal cancer. Instead, the researchers found that women and men who regularly drank two or more cups of decaffeinated coffee per day had a 52 percent lower risk of colorectal cancer than women and men who did not drink decaffeinated coffee. Colorectal cancer was the lowest among participants who drank a daily average of half a cup of decaffeinated coffee.
In addition, Michels and the research group found that women and men were part of a trend of decreasing caffeine consumption. From 1980 through 1994 women gradually decreased the amount of caffeinated coffee they consumed – in 1980, 22.5 percent of the women did not drink coffee and 25 percent drank four or more cups of caffeinated coffee per day. In 1994, 13.2 percent of the women did not drink coffee and 14.2 percent drank four or more cups per day. A similar but weaker trend was found among the men.
“People may be concerned about the effects of caffeine on health and some of them may have switched to decaffeinated coffee. Further study is needed to confirm the inverse association between decaffeinated coffee and colorectal cancer risk,” Michels said.
The average cup of American-style coffee (6 oz.) contains about 100 milligrams of caffeine; a properly prepared single serving of espresso (2 oz.) 120 milligrams. The average cup of tea delivers about 40 milligrams; the average chocolate bar about 20 to 60 milligrams. A 12-ounce bottle of cola drink contains 40 milligrams, about as half as much as a cup of coffee.
Please contact BWH Media Relations for more information at (617) 534-1600 or BWHMediaRelations@partners.org.
BWH is a 747-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare System, an integrated health care delivery network. BWH is committed to excellence in patient care with expertise in virtually every specialty of medicine and surgery. The BWH medical preeminence dates back to 1832 and today that rich history in clinical care is coupled with its national leadership in quality improvement and patient safety initiatives, dedication to educating and training health care professionals, and strength in biomedical research. With $370M in funding and more than 500 research scientists, BWH is an acclaimed leader in clinical, basic and epidemiological investigation - including the landmark Nurses Health Study, Physicians Health Studies, and the Women's Health Initiative. For more information visit www.brighamandwomens.org
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