Coffee might stave off more than just sleep, according to research showing that those who chug a lot of java have a lower rate of head and neck cancers.
Prior research on the link between coffee and cancer has yielded mixed results. Some studies, for example, have found lower rates of kidney and ovarian cancer among coffee drinkers, while there appears to be no effect for colon cancer.
For the new report, scientists pooled results from nine earlier studies on head and neck cancers, which also included information on coffee or tea drinking. In each study, cancer patients had been compared to either the general population or to hospital patients who didn't have cancer.
Overall, the risk of developing head and neck cancers was 12 percent lower in people who drank coffee compared with those who didn't, after accounting for a variety of factors, including cigarette smoking.
And the more coffee consumed, the lower the cancer risk. In those who gulped more than four cups a day, for instance, the risk was reduced by more than a third. Still, the odds of getting this type of cancer are slim to begin with: in the U.S., only about 1 in 10,000 does so every year.
For cancer of the voice box, or larynx, coffee didn't seem to play a role; nor did tea or decaffeinated coffee for any type of head and neck cancer.
Strictly speaking, the data don't prove that coffee itself protects against cancer. There could be other factors associated with coffee drinking that explain the lower cancer risk, or people with the disease might have cranked down their coffee intake for some reason.
If coffee really does make a difference, there are several ways this could happen, although all are speculation at this point, the researchers note in the journal Cancer Epidemiology, Biomarkers & Prevention.
"Besides caffeine, coffee contains more than a thousand chemicals," they say, adding that the compounds cafestol and kahweol may be protective against carcinogens that would normally damage our genes.
