However, six or more only cut the likelihood by around 7%, says the study.
Antioxidants may be responsible -- other caffeinated drinks such as tea do not bring the benefits but decaffeinated coffee does, according to the researchers at the Karolinska Institute in Stockholm.
For their study, the researchers pooled all the results from eight previous researches involving nearly a half million people since the mid-1960s.
According to them, coffee may protect the brain from so-called "bad" cholesterol but fears of increased blood pressure remain.
The findings have been published in the American Journal of Epidemiology.
From the September 19, 2011, Prepared Foods' Daily News.