Women drinking coffee can reduce the risk of depression

Researchers at the Harvard School of Public Health asked more than 50,000 women aged 50 to 70 about how much coffee they drank each day. Women who drank two to three cups of caffeinated coffee a day had a 15 percent lower risk of depression, and those who drank four or more cups a day had a 20 percent lower risk of depression. Dr Karestan Koenen, of Colombia University's Mailman School of Public Health, said: "We don't know exactly how it works, but there may be a biological relationship: caffeine affects brain chemicals that cause depression."

Women are twice as likely to suffer from depression as men. Depression affects one in five women in the United States.

The women surveyed were moderate coffee drinkers, with most drinking less than six cups a day. Doctors warn that drinking large amounts of caffeinated coffee may have negative effects on some people, including insomnia, nervousness, restlessness and a rapid heartbeat.

The researchers found no link between decaf coffee and depression. These new findings do not prove that caffeinated coffee causes lower depression in women than decaffeinated coffee, they said, and more research is needed to prove a link.

The women were asked how many caffeinated and decaffeinated beverages they drank daily, including soda and tea, and most of their caffeine came from coffee.