Drinking Coffee Reduces Risk of Developing Colorectal Cancer

Coffee drinkers have a lower risk of developing colorectal cancer, according to a study by researchers from the University of Southern California (USC).

The study, published in Cancer Epidemiology, Biomarkers & Prevention, examined more than 5100 men and women diagnosed with colorectal cancer within the past 6 months. For the control group, 4000 men and women without a history of colorectal cancer were recruited.

“We found that drinking coffee is associated with lower risk of colorectal cancer, and the more coffee consumed, the lower the risk,” said senior study author Stephen Gruber, MD, PhD, MPH.

During the study, participants reported their daily consumption of espresso, instant, decaffeinated, and filtered coffee, as well as their total consumption of additional liquids.

A questionnaire was also given to gain information on other colorectal cancer risk factors, such as a family history of cancer, diet, smoking, and physical activity.

The results of the study showed that moderate consumption of coffee between 1 to 2 servings a day was associated with a 26% reduction in the odds of developing colorectal cancer after adjusting for risk factors.

When participants drank more than 2.5 servings of coffee a day, the risk of developing colorectal cancer decreased up to 50%. The decreases were seen in all types of coffee, whether caffeinated or not.

“We were somewhat surprised to see that caffeine did not seem to matter,” Gruber said. “This indicates that caffeine alone is not responsible for coffee's protective properties.”

There are several different factors in coffee that contribute to colorectal health. Caffeine and polyphenol can act as antioxidants and limit the growth of potential colon cancer cells.

Diterpenes could prevent cancer by enhancing the body’s defense against oxidative damage. Meanwhile, melanoidins that are generated during the roasting process are hypothesized to encourage colon mobility.

“The levels of beneficial compounds per serving of coffee vary depending on the bean, roast and brewing method,” said first author Stephanie Schmit, PhD, MPH. “The good news is that our data presents a decreased risk of colorectal cancer regardless of what flavor or form of coffee you prefer.”

The large population-based study was conducted by researchers from the Clalit National Israeli Cancer Control Center and USC Norris. The results were representative of many different coffee-drinking populations.

“Although coffee consumption in Israel is less common and with more type-variability than in the United States, our results indicate similarities in risk reduction with use consumption of various types of coffee,” said lead researcher Gad Rennert, MD, PhD. “While the evidence certainly suggests this to be the case, we need additional research before advocating for coffee consumption as a preventive measure,” Gruber added. “That being said, there are few health risks to coffee consumption, I would encourage coffee lovers to revel in the strong possibility that their daily mug may lower their risk of colorectal cancer.”