Researchers from the University of Southern California (USC) Norris Comprehensive Cancer Center of Keck Medicine of USC have found that regular coffee drinking decreases your risk of colon cancer. The study included a large sample of 5,145 colon cancer cases and 4,097 healthy subjects from the Molecular Epidemiology of Colorectal Cancer (MECC) study which is a population-based case–control study conducted in northern Israel. The study was published by The American Association of Cancer Research in the April 1, 2016, issue of Cancer Epidemiology, Biomarkers & Prevention.
Coffee contains a great number of bioactive compounds, some of which are beneficial to colon physiology. Previous studies suggested that coffee drinking is a protective factor against colorectal cancer. Furthermore, a meta-analysis of the literature regarding this topic found a borderline protective effect of drinking coffee against colorectal cancer. The meta-analysis included over 500 papers that examined the link between coffee and cancer. However, the evidence to support this idea is insufficient. For this reason, researchers from the USC set out to find if regular coffee drinkers had a lower colon cancer risk.
What they did?
The researchers examined a sample of 5,145 men and women who had been diagnosed with colorectal cancer in the past six months and 4,097 men and women with no previous history of colorectal cancer to serve as controls. The subjects reported their daily coffee consumption as well as what type of coffee they drank (espresso, instant, decaffeinated). The questionnaire also included other information regarding their risk of colorectal cancer such as family history of cancer, activity levels, and smoking. Researchers also examined the link between coffee drinking and cancer site and the differences between the ethnic groups involved.
Stephen Gruber, MD, PhD, MPH who is the director of the USC Norris Comprehensive Cancer Center and the senior author of the study states that they have found that coffee consumption was generally associated with a lower risk of colorectal cancer and the more coffee a person drank, the lower their risk was. Coffee consumption was all in all associated with ha 26% lower risk of colorectal cancer with a confidence interval of 95%. The association was the same for all types of drink, be that decaffeinated or caffeinated coffee. When researchers compared the servings to cancer risks, they found that those who drank more than two servings of coffee a day had an even lower risk of colorectal cancer than those who drank one or no servings per day.
Because the results were the same for decaffeinated and caffeinated coffee drinking, Gruber suggests that caffeine is not the responsible factor in coffee’s cancer-protective properties. Coffee contains a great number of polyphenols which are plant compounds known for their antioxidant properties. Oxidative stress caused by free radicals is a recognized contributing factor in cancer development. Along with the body’s immune system, antioxidants help protect the cells from cancer and oxidative stress. Other ways coffee may prevent the development of colon cancer is through melanoidins which are generated through the roasting process and which increase colon mobility leading to more bowel movements. Diterpenes found in coffee may also improve the body’s ability to fight oxidative stress.
The study’s first author Stephanie Schmit, PhD, MPH stated that the beneficial ingredients in a single serving of coffee greatly depend on bean quality, roasting process, and brewing method. And although the study found that the cancer-fighting benefits of coffee did not depend on the type of coffee, it might be better to choose coffee brands and brewing processes that preserve as much of the beneficial ingredients in coffee as possible.
The main strength of this large population-based study is that the results represent different coffee-drinking populations regarding drink type and ethnicity. While more research is needed to understand how exactly coffee benefits colorectal health and in this way prevents cancer, Gruber suggests we revel in the possibility that coffee may be good for us. Considering that there are few health risks of coffee drinking, it would be a good idea to include coffee in your regular diet especially if you are in the high-risk group of colon cancer. And because colorectal cancer is one of the leading causes of cancer-related deaths worldwide, studies like there are helping in the development of treatment options and alternative remedies for cancer prevention.
The health benefits of coffee were previously overlooked mostly because coffee being a stimulant was considered to be unhealthy. But newer studies suggest that the polyphenol content of coffee might actually be beneficial for out health. This might especially be true regarding colorectal health as more and more studies are finding the evidence that regular coffee drinking reduced the risk of this type of cancer and which was also confirmed in the USC study.