“I would encourage coffee lovers to revel in the strong possibility that their daily mug may lower their risk of colorectal cancer.” So says Stephen Gruber, M.D., Ph.D., director of the University of Southern California (USC) Norris Comprehensive Cancer Center and the senior author of a new study, “Coffee Consumption and the Risk of Colorectal Cancer.” Dr. Gruber and his USC colleagues conducted this study, which appeared April 1 in the journal Cancer Epidemiology, Biomarkers & Prevention, with the assistance of a research team led by Gad Rennert, M.D., Ph.D., director of the Clalit National Israeli Cancer Control Center in Haifa, Israel.
The study involved 5,145 male and female patients diagnosed with colorectal cancer within the past 6 months and a control group of 4,097 with no history of colorectal cancer. Data on daily consumption of coffee, type of preparation, as well as consumption of other liquids, family history of cancer, diet, physical activity, and smoking was collected via a detailed questionnaire and analyzed statistically.
The investigators found that one to two servings of coffee per day were associated with a 26% reduction in the odds of developing colorectal cancer after adjustment for known risk factors. If the number of coffee servings was more than 2.5 per day, the colorectal cancer risk decreased up to 50%.
And this decreased risk was for both caffeinated and decaffeinated coffee. “We were somewhat surprised to see that caffeine did not seem to matter. This indicates that caffeine alone is not responsible for coffee’s protective properties,” said Dr. Gruber.
The study's first author, Stephanie Schmit, Ph.D., added that “The good news is that our data presents a decreased risk of colorectal cancer regardless of what flavor or form of coffee you prefer.”
Coffee is a complex conglomeration of chemical compounds. Its possible active components include antioxidants, such as chlorogenic acids, polyphenols, and caffeine; melanoidins that promote colon motility; and dipterenes, such as cafestol and kahweol, which exert anticarcinogenic activity.
There has been a growing body of evidence suggesting that consumption of coffee—as much as four or more cups per day—might be a protective factor for gastrointestinal cancers, including liver cancer, as well as type 2 diabetes and even dementia. The USC study provides “evidence of an inverse, dose-response association between coffee drinking and the odds of colorectal cancer, colon, and rectal cancer.” But Dr. Gruber stresses that “While the evidence certainly suggests this to be the case, we need additional research before advocating for coffee consumption as a preventative measure.”
According to the American Cancer Society, colorectal is the second leading cause of cancer deaths for both sexes in the United States, with over 49,000 deaths predicted for 2016.