The Queen sent almost 15,000 congratulatory messages to people celebrating their 100th birthday last year, compared with fewer than 3,000 in 1952, the first year of her reign. That is testament to progress – societies are successfully ageing across the world. But as we grow older, the risk of mental as well as physical decline grows too. While we may look forward to a card from the monarch and be resigned to failing eyesight and creaking joints, the prospect of a descent into mumbling incoherence fills us with terror.
The rise of dementia is one of the greatest disease threats the world faces. Less than a year ago, a major report spelt out the nature of the challenge and delivered the gloomiest possible prognosis. It showed that while the number of people affected is projected to almost double every 20 years – from 44 million globally today to 76 million in 2030 and 135 million in 2050 – the search for effective treatments was grinding to a halt.
Image credit: Alamy