Coffee, Cancer and Your Health
Last week’s new report on endometrial cancer was the first time AICR/WCRF found that coffee reduces the risk of a cancer. The risk reduction was relatively small, but this latest finding follows a series of positive findings for coffee lovers
Coffee and Endometrial Cancer
The CUP report looked at the eight relevant studies on coffee and endometrial cancer risk, including more than 300,000 women. For both caffeinated and decaffeinated, the report found a 7 percent reduced risk for that daily cup of coffee compared to none.
This marks an average taken across a range in amounts of coffee consumed in the studies, says Rachel Thompson, PhD, an epidemiologist at WCRF International who manages the Continuous Update Project.
“We also know that the more coffee you drink, the bigger the effect up to a limit. However, in the studies there were few people who consumed more than five cups of coffee a day so we really don’t know what the effect of drinking six or more cups a day is on endometrial cancer,” says Thompson.
Several biological mechanisms could explain the link between coffee drinking and developing endometrial cancer. Some components, including chlorogenic acid, have strong antioxidant properties that can prevent DNA damage, improve insulin sensitivity and inhibit glucose absorption in the intestine, all of which could reduce risk.
For cancer risk
AICR has no cancer prevention recommendations on coffee because there are too many unknowns relating to how coffee affects overall cancer risk as well as other conditions. Of the 17 cancers studied, there was enough evidence for AICR/WCRFs continuous update reports to conclude that coffee has no affect on pancreatic and kidney cancers. Evidence was too limited to draw a conclusion for the other cancers, says Thompson.
Other reviews of coffee and cancer studies suggest the beverage may have a protective effect, such as this 2011 study that found coffee intake reduced risk of a deadly form of prostate cancer.
But again, the research is not strong enough for WCRF/AICR to draw a conclusion.
For overall health risk
In decades past, coffee was linked with possible increased risk for several diseases, including cancer. That has changed in recent years.
Now research suggests that coffee reduces risk of type 2 diabetes, says Karen Collins, MS, RDN, Nutrition Advisor for AICR and expert on the diabetes-cancer connection. This could be due to coffee’s possible role in reducing abnormally high insulin levels. For diabetes, “it is likely especially helpful for women who are overweight and inactive; they are more likely to be insulin resistant.”
Research also links coffee consumption to lower risk of premature death. (An August study did find that more than four cups of caffeinated coffee a day increase risk of death among women under age 55, but that goes against the majority of findings.)
Studies have linked coffee intake to lower risk of dementia, Parkinson’s disease and cardiovascular disease.
A small tweak
For endometrial cancer, drinking coffee is a “small tweak that can help,” says Collins. And for those who enjoy coffee, drinking a moderate amount may provide health benefits. Coffee is among the top sources of antioxidants among Americans.
But beware of the flavored sugary coffees, which can zoom into the hundreds of calories and prompt insulin surges, says Collins. If these coffees are contributing to weight gain – or not helping you get to a healthy weight – that can mitigate any health benefits. Excess body fat is linked to increased risk of seven cancers, including endometrial, along with type 2 diabetes and other chronic diseases.
There are reasons people may need to avoid or limit coffee, such as those who experience gastroesophageal reflux disease. Excess caffeine is also a concern for women who are pregnant.
Yet for many, says AICR Nutrition Manager Alice Bender, MS, RDN, research suggests a moderate amount of coffee is safe and may even be helpful for some health concerns. A moderate amount is generally considered two to three cups a day, she says.
For more information on coffee, cancer risk, and what the beverage contains, visit AICR’s Foods that Fight Cancer: Coffee.