A few cups of coffee a day may help keep the blues at bay. According to a large new study, women who drink caffeinated coffee are less likely to become depressed — and the more they drink, the more their risk of depression goes down.
The study, which was published Monday in the Archives of Internal Medicine, included more than 50,000 women between the ages of 30 and 55 who periodically filled out surveys about their coffee consumption and health. None of the women had depression symptoms (or a history of depression) at the start of the study, but during the next 10 years roughly 5% received a depression diagnosis or began taking antidepressant medication.
Compared with women who drank little or no caffeinated coffee, those who averaged two to three cups per day were 15% less likely to develop depression, even after the researchers took into account a wide range of potentially mitigating factors including marital status, church or community participation, and various health measures. Drinking four cups a day was associated with a 20% lower risk of depression.
The study doesn’t prove cause and effect, so there’s no reason to believe that drinking cup after cup will actually prevent depression, the researchers say.
“There’s no need to start drinking coffee,” says study co-author Alberto Ascherio, M.D., a professor of epidemiology and nutrition at the Harvard School of Public Health, in Boston. “The message is that coffee is safe to drink, with no adverse effects. That’s really all that can be said.”
Previous research, including a study published last year that was conducted among men in Finland, has linked caffeine consumption to a lower risk of depression and suicide.
It’s not clear why coffee might protect against depression. Some experts have speculated that the antioxidants in coffee may have health benefits, but in the new study people who drank only decaf were no more or less likely to be depressed than women who drank no coffee at all.
The caffeine might be responsible, but the researchers weren’t able to confirm or deny this theory because there wasn’t enough data available to determine whether drinking caffeinated tea or sodas is linked to depression risk in the same way as coffee consumption. Eighty-two percent of the study participants drank coffee, while only 13% and 6% drank tea and soft drinks, respectively.
