London, Nov 27 (IANS): Researchers have found that drinking up to five cups of coffee per day may help curb Alzheimer's risk by 20 percent.

Caffeine in coffee helps prevent the formation of amyloid plaques and neurofibrulary tangles in the brain - two hallmarks of Alzheimer's, the findings showed.

"The findings suggest that regular coffee consumption over a lifetime is associated with a reduced risk of developing Alzheimer's, with an optimum protective effect occurring with three to five cups of coffee per day," said Arfram Ikram, assistant professor in neuroepidemiology at Erasmus Medical Centre Rotterdam in the Netherlands.

The researchers explored the compounds within coffee, which may be responsible for this protective effect and identified caffeine and polyphenols as key candidates.

In addition to this, both caffeine and polyphenols reduce inflammation and decrease the deterioration of brain cells - especially in the hippocampus and cortex, areas of the brain involved in memory.

Moderate coffee consumption was associated with a lower risk of developing dementia over a four year follow-up period, however the effect diminished over longer follow up period.

The findings were recently presented at the 2014 Alzhemier Europe Annual Congress in Glasgow, Britain.