Health Benefits of Coffee

+Brain Gains. Moderate coffee drinking—between 1 and 5 cups daily—may help reduce risk of dementia and Alzheimer’s disease, as well as Parkinson’s disease, studies suggest. How? Coffee’s antioxidants may prevent some damage to brain cells and boost the effects of neurotransmitters involved in cognitive function, say experts. ­Preliminary studies have noted that as coffee (or tea) intake rises, ­incidence of glioma, a form of brain cancer, tends to drop. Some ­researchers speculate that compounds in the brews could activate a DNA-repairing protein in cells—possibly preventing the DNA damage that can lead to cells becoming cancerous.

+Defeating Diabetes. Studies link frequent coffee consumption (4 cups per day or more) with a lowered risk of developing type 2 diabetes. Scientists suspect that antioxidant compounds in coffee—cholorogenic acid and quinides—may boost cells’ sensitivity to insulin, which helps regulate blood sugar. While most of the research didn’t assess whether the brews were caffeinated, decaf may be even better, since other studies have found that caffeine tends to blunt the insulin-sensitivity boost.

+Hearty Benefits. Some studies show that moderate coffee drinkers (1 to 3 cups/day) have lower rates of stroke than non-coffee-drinkers; coffee’s antioxidants may help quell inflammation’s damaging effects on arteries. Some researchers speculate that the compounds might boost activation of nitric oxide, a substance that widens blood vessels (lowering blood pressure). More java isn’t better: a 5-cup or more daily habit is associated with higher heart disease risks. Researchers ­believe excessive caffeine may sabotage the antioxidants’ effects.

+Liver Lover. Though the research is limited at best, it appears that the more coffee people drink, the lower their incidence of cirrhosis and other liver diseases. One analysis of nine studies found that every 2-cup increase in daily coffee intake was associated with a 43 percent lower risk of liver cancer. Possible explanation: caffeine and antioxidant chlorogenic and caffeic acids in coffee might prevent liver inflammation and inhibit cancer cells.