Of the types of cancer that affect both men and women, colorectal cancer, which includes cancer of the colon and rectum, is the second leading cause of cancer-related deaths in the United States, and the third most common cancer, according to the Centers for Disease Control and Prevention (CDC).
Unfortunately, when it comes to colorectal cancer, the biggest risk factors are out of your control. The No. 1 risk factor is your age. Ninety percent of cases are diagnosed in people over the age of 50. The next biggest risk factor is genetics. Finally, people who suffer from inflammatory bowel disease are at a much higher risk.
OK, what about the things you can do something about?
Well, for starters, based on solid scientific evidence, excessive alcohol use, cigarette smoking and obesity are all associated with an increased risk of incidence and/or death from colorectal cancer. So, taking a page from the book of common sense, it is in your best interest to limit your alcohol intake, refrain from smoking and shed that extra weight. Additionally, research has shown that physical activity has been linked with a 24 percent reduction in colorectal cancer incidence.
As for other things you can do to reduce your risk, the research has been less conclusive. But a new study shows that drinking green tea could play a role.
Green Tea and Colorectal Cancer Prevention
Tea had been studied for its cancer-prevention properties largely due to the fact that it contains antioxidants known as polyphenols. In particular, the predominant polyphenols in green tea include EGCG and EGC, and these may help offset free radical damage and protect your cells.
In the study at hand, researchers looked at 60,567 Chinese men aged 40 to 74, approximately 66.6 percent of whom were regular green tea drinkers. For their purposes, regular consumption was defined as having ever drank tea at least three times per week for more than six consecutive months.
Interestingly, when compared with men who didn’t drink green tea, the men who regularly drank it were slightly younger, more likely to smoke cigarettes and drink alcohol, less physically active and tended to consume more red meat.
During a mean follow-up period of 4.6 years, 243 cases of colorectal cancer were reported (133 colon and 110 rectal). Of those, 123 men had early-stage tumors and 93 had late-stage tumors. And the mean age at diagnosis was 66.4 years.
In looking at the overall study population, researchers found that green tea consumption was inversely associated with colorectal cancer risk, but the results were only marginally significant. However, among the non-smokers in the group, the inverse association was statistically significant.
Put another way, while green tea consumption did not seem to meaningfully lower risk for colorectal cancer in cigarette smokers, each 2 g increment of intake of dry green tea leaves per day (which is approximately equivalent to the amount found in one tea bag) was associated with a 12 percent reduction in risk among those men who did not smoke cigarettes.
Researchers concluded, “Consumption of green tea was associated with an overall 23% reduction in risk of colorectal cancer. After accounting for effect modification by cigarette smoking, we found that risk was reduced by 46% among non-smokers.”
So it seems that green tea may be powerful enough to help reduce the risk of colorectal cancer in lower-risk populations, i.e., non-smokers, but not powerful enough to offset the risk you bring upon yourself if you choose to light up.
If you’re a smoker and you’re interested in reducing your risk of not only colorectal cancer, but just about every kind of cancer out there, the first step is an obvious one: quit.
Now, as anyone who has ever been addicted to cigarettes knows, that is easier said than done. So if you’ve tried in the past and failed, you might be interested in these unconventional tips to help you kick the habit.
As for drinking green tea, while the results from this study are certainly promising, the National Cancer Institute still deems the relationship between tea consumption and cancer risk to be inconclusive. But that shouldn’t stop you.
Think of it this way: Most of us can’t live without our daily caffeine fix, be it coffee, tea or energy drinks, so why not opt for the one that contains the highest amount of antioxidants and that emerging research is linking to cancer prevention? It seems like a no-brainer.
Additionally, dietary supplements containing green tea extract are available at most health food stores and online if you prefer to go that route.
 Wolin KY, Yan Y, Colditz GA et al.: Physical activity and colon cancer prevention: a meta-analysis. Br J Cancer. 2009;100(4):611-6.
 Yang G et al. Green tea consumption and colorectal cancer risk: a report from the Shanghai Men’s Health Study. Carcinogenesis. 2011;32(11);684-88.