Suspected by some and consumed by many millions, the most certain thing about coffee is that it continues to surprise medical researchers. Mildly mind-altering, even toxic in enormous concentrations, “Joe” contains enough potent chemical compounds to justify hundreds of ongoing studies, including large scale surveys by the Harvard and Mayo Clinics, as well as the National Institutes of Health.

These examine coffee’s impact on a large number of our most devastating ailments, from heart disease to diabetes, to Parkinson’s and Alzheimer’s syndromes…and cancer, of course — many kinds. Each has its own complex mechanism, but here’s a brief and partial synopsis of current research findings:

  • Endometrial Cancer: A long-term Harvard study found that women ages 34 to 59 who drank four cups a day had a 25 percent lower risk of this illness.
  • Cancers of the Breast: At least one form of a high-risk breast cancer is 57 percent less likely to occur among women who drank five or more cups a day. (Note that five cups a day is typically over 500 mg of caffeine — an amount that would leave moderate drinkers vibrating from a perch near the ceiling.)
  • Prostate Cancer: According to the Journal of the National Cancer Institute, cited in a Health Radar article, men with serious coffee habits, consuming six or more cups a day, “had a 60 percent lower risk of the most deadly form of the disease, and a 20 percent lower chance of developing any type of prostate cancer.” (Presumably, these subjects were interviewed on rooftops.)
  • Head and Neck Cancers: An American Association of Cancer research release reports that “regular” coffee drinkers — four or more cups a day — had a 39 percent decreased risk of oral cavity and pharyngeal cancers.
  • Brain Cancer (gliomas): A British study from the Imperial College of London found that “Consumption of five or more cups of coffee and tea daily compared with no consumption was associated with a decrease risk of glioma of 60 percent.”
  • Liver Cancer  (hepatocellular carcinoma/HCC): Per findings posted at News Medical, “At least eleven studies conducted in southern Europe and Japan” concluded that the chances of contracting the third most deadly of cancers “showed a 41 percent reduction of HCC risk among coffee drinkers compared to those who never drank coffee.”

That’s hardly the end of the findings to be sure. Evidence also reveals coffee’s apparently positive effects on uterine, colon and basil cell cancers, among others. There are, however, other concerns, as a Harvard Health Publications article makes clear: “…coffee is not completely innocent. Caffeine, coffee’s main ingredient, is a mild addictive stimulant. And coffee does have modest cardiovascular effects, such as increased heart rate, increased blood pressure, and occasional irregular heartbeat that should be considered.”

In other words, much remains to be learned, and more surprises will follow. Until then, Harvard suggests “moderation is the key…negative effects of coffee tend to emerge in excessive drinking so it is best to avoid heavy consumption.”

That’s the standard formula, of course. But given the results cited above, it’s fair to ask now: “Just what does moderate mean?” Two cups a day? Or the five or six often found most beneficial?

Will your coffee intake change, based on what’s already known today? Please add your comments below.