By 2050 the number of sufferers could be more than three times the current figure of 35.6 million, the UN body said.

The report published with Alzheimer's Disease International estimates the cost of treating and caring for those with the condition at US$604 billion (S$760.6 billion) a year.

Dementia is caused by a variety of brain illnesses that affect memory, thinking, behaviour and the ability to perform everyday activities.