Drinking two to four cups of coffee daily appears to reduce the risk of suicide in both men and women by 50 per cent, according to a new study.

Harvard School of Public Health in the US reviewed data from three previous US studies and found the risk of suicide amongst adults who drank several cups of caffeinated coffee on a daily basis was about half that of that compared to those who drank decaffeinated coffee, very little coffee or no coffee at all.

The study, examined the habits of 200,000 men and women, investigating their caffeine consumption both coffee and non-coffee sources – including tea, caffeinated soft drinks, and chocolate.

Lead researcher, Michel Lucas said the research suggested there was little advantage to be gained from drinking more than two or three cups of coffee daily – around 400mg of coffee. And adults are advised not to increase their coffee intake because of potential side-effects.

Caffeine works by stimulating the central nervous system but may act as a mild antidepressant by increasing production of certain ‘feel good’ neurotransmitters in the brain, including serotonin, dopamine, and noradrenaline.
This could explain why previous epidemiological studies have found a lower risk of depression among coffee drinkers in past, the researchers reported.