5 Most Surprising Reasons to Drink Coffee
Feeling jittery about whether to drink coffee? Percolate on this: Coffee's benefits considerably outweigh its negatives, researchers now believe. Although caffeine can cause anxiety and insomnia in some people, the beverage's unique properties -- such as more powerful antioxidants than from any other source in the American diet, including fruits and vegetables -- can do a lot of good. Just be sure to spring for organic coffee, says Beth Reardon, director of nutrition for Duke Integrative Medicine, since coffee beans are among the most heavily sprayed crops (all those chemicals can undo the benefits).
Here are the five surprising reasons to sip coffee:
1. Coffee slashes your risk of developing type 2 diabetes.
The health benefit: The more coffee you drink, the less likely it is you'll develop type 2 diabetes, numerous studies have shown. For example, postmenopausal women who drink at least four cups of coffee a day are less than half as likely to develop type 2 diabetes as those who don't drink coffee, according to a 2011 study of more than 700 women by the UCLA Schools of Public Health and Medicine.
In fact, every additional cup is thought to reduce the excess risk of type 2 diabetes by 7 percent, according to Australian researchers in a 2009 Archives of Internal Medicine meta-analysis of 18 different studies, which linked coffee drinking and diabetes prevention.
How it works: Coffee is thought to improve the body's tolerance to glucose by speeding metabolism and improving insulin tolerance.
The UCLA researchers discovered one possible molecular mechanism for this. Coffee consumption increases blood levels of a protein called sex hormone-binding globulin (SHBG), which seems to offer protection against type 2 diabetes in those who have a certain type of genetic mutation. (Decaf coffee didn't show this effect, however.)
If you're already showing signs of prediabetes, of course, you'll want to refrain from dunking doughnuts in that joe.
2. Coffee can counter cancerous cell damage.
The health benefit: Coffee was once believed to cause cancer -- but that was before researchers factored in such related behaviors of frequent sippers as smoking and drinking alcohol. Today, there's mounting evidence that coffee may be protective against certain cancers, possibly by enhancing DNA repair.
Some of the best evidence concerns liver damage and liver cancer, which strikes more than 18,000 Americans a year. Multiple studies have found an inverse relationship between coffee consumption and liver cancer risk, including a 2007 meta-analysis of nine different studies.
Cancer-prevention researchers are finding similar benefits of coffee drinking versus other forms of the disease. In 2011, for example, a Harvard team found that women who drink several cups of coffee a day (caffeinated or decaf) have a lower risk of endometrial cancer. Another 2011 Harvard study reported that for men who consumed six cups of coffee a day, their risk of lethal prostate cancer was fully 60 percent lower than lesser coffee drinkers, and their risk of any kind of prostate cancer was 20 percent lower.
Other studies have linked coffee drinking to a reduced risk of colon cancer, rectal cancer, oral cancer, and esophageal cancer.
How it works: Coffee contains hundreds of chemical compounds -- among them antioxidants and anti-inflammatory compounds that can decrease markers for the damaging process of inflammation. The highly active antioxidant compound methylpyridinium, for example, is found almost exclusively in coffee (both caffeinated and decaf types), due to the beans' roasting process. Espresso has two to three times the amount of this anticancer compound as a medium-roast coffee, according to the German researchers who identified it in coffee.
