One in three Britons born this year will go on to develop dementia, a report reveals.

Experts warned of a ‘looming national health crisis’ and called for urgent action by politicians and scientists to deal with the potential care timebomb.

Some 27 per cent of boys born in 2015 will develop the ‘life-shattering’ brain disease when they hit 60-plus, a report commissioned by Alzheimer’s Research UK shows.

Girls face an even bleaker future, largely due to their longer life expectancy, with 37 per cent destined to suffer from dementia unless better treatments are developed.

The charity’s Dr Matthew Norton said: ‘These figures underline a stark reality: as people are living longer, more and more will develop dementia, if action is not taken now to tackle the condition.’

The prediction comes in a report for the charity by the Office of Health Economics, a respected independent consultancy.

Statisticians combined government estimates on the life expectancy of babies born today with data on how common dementia is at various ages. Importantly, their estimates are only conservative.

Genes, diet and lifestyle have all been linked to Alzheimer’s and other forms of dementia – but ageing has by far the biggest effect.

It is calculated that if the onset of the disease could be delayed by just five years, the number of people who develop the condition would be cut by a third. But existing drugs have limited benefit and none are yet able to hold it at bay.

With various studies predicting a surge in cases as the population ages, David Cameron has described dementia as ‘the key health challenge of this generation’. Alzheimer’s Research UK said: ‘We owe it to people living with the heartache of dementia now, and to our children, to strive for better treatments and preventions and a future where dementia is a thing of the past.’

Dr Norton, the charity’s head of policy, added: ‘It’s wonderful news that each generation is living longer than the last, but it’s important to ensure that people can enjoy these extra years in good health.

‘Dementia is our greatest medical challenge and, if we are to beat it, we must invest in research to find new treatments and preventions.

‘Research has the power to transform lives, and our actions now will help determine the future for children born today.’

The study was released to mark World Alzheimer’s Day.

George McNamara, of the Alzheimer’s Society, said: ‘Dementia is already the biggest health challenge this country faces. It costs the UK in excess of £26billion, which equates to £30,000 per person with dementia – more than the cost of either cancer or heart disease.

‘We urgently need long-term, sustainable research funding that is proportionate to the economic and social impact of the condition.’

Professor Hugh Perry, of the Medical Research Council, said: ‘These new figures are a sharp reminder of the challenges we face as dementia gains more of a foothold in our lives. The problem is clear and the need for solutions is pressing.’

Age UK said it was important not to forget those struggling with dementia now. The charity’s Caroline Abrahams said: ‘With growing numbers being diagnosed with dementia, it’s more important than ever to ensure that everyone is given the help they need to live with dignity.’