It is a condition that is destined to have a huge global impact in the coming decades.

And with an ageing population, the number of sufferers from Alzheimer’s could quadruple over the next 40 years.

More than 26 million people worldwide are thought to be living with the illness but researchers from John Hopkins University in Baltimore, Maryland, predict that will rise to more than 106 million by 2050 with the biggest rise in Asia.

In the UK, the Alzheimer’s Society say about 1.7m people will suffer with disease by the middle of the century.

Already, 700,000 people in Britain have dementia, of which 400,000 are Alzheimer's sufferers, a condition that includes memory loss, confusion and problems with speech and understanding.

Along with the ageing global population, advances in medicine are seeing people live longer, which will add to the global rise in cases.

Researcher Professor Ron Brookmeyer, who revealed the predicted rise at the International Conference on the Prevention of Dementia in Washington DC, said: “We face a looming global epidemic of Alzheimer's disease as the world's population ages.

"By 2050, one in 85 people worldwide will have Alzheimer's disease. However, if we can make even modest advances in preventing Alzheimer's disease or delay its progression, we could have a huge global public health impact."

The Alzheimer’s Society in the UK wants a nationwide strategy to deal with the issue, fearing the rise in the condition will have a massive impact on the NHS. It already costs the nation £17bn a year. There is no cure for Alzheimer’s but drug treatment can slow the development of symptoms.

Experts have now unveiled a new test that can predict a person's risk of dementia in the next six years, combining medical history, cognitive function and a physical examination and is 87 per cent accurate.

Alzheimer’s Society chief executive Neil Hunt said tools to predict dementia and encourage healthy lifestyles were important to combat the disease.

But he warned: "Dementia is incurable and discovering you have a high chance of developing the condition may frighten people rather than empowering them into action to reduce their risks."