Urgent action needs to be taken across society to halt the spiralling numbers of dementia cases in the UK, doctors and scientists have warned. Measures should include boosting numbers of people who donate their brain to research banks, increasing dementia research funds and encouraging young researchers to work in the field.
The call comes in the runup to the Alzheimer's Action Day on Friday, when campaigners, care workers and medical staff will join in activities designed to raise awareness of the growing problem of dementia in the UK.
"More than a million people could soon be afflicted with Alzheimer's and other forms of dementia," said Professor Andrew Lees, clinical director of the Queen Square Brain Bank for Neurological Disorders. "We need to act very speedily to try to halt this from becoming a crisis. Getting people to donate brains that we can study and analyse to try to understand the basic science behind dementia would be a welcome development, for a start."
The crisis rests on the fact that more and more people are living longer. The life expectancy of a man in the UK has risen from 72 to 78 over the past 20 years and for a woman it has gone from 78 to 82, with further rises expected over the next decade. But as people get older, more and more develop dementia.
"The single key risk factor for succumbing to dementia is a person's age," said Lees, whose ebook, Alzheimer's: The Silent Plague, is to be published by Penguin this week. "There are factors like obesity and taking exercise involved, but it is age that matters above all else."
For a person who is 65, that risk is one in 14. For someone over 80, that rises to one in six. As more Britons have reached their 80s, increasing numbers have succumbed to dementia. As a result, 820,000 people are affected today in the UK. Two-thirds of these dementia cases are made up of patients with Alzheimer's, which is by far the most common form of dementia, with the rest suffering conditions such as vascular dementia, caused when patients have a series of strokes.
This swelling tide of patients threatens to overwhelm health authorities. Caring for a person with Alzheimer's costs £27,650 a year, a figure higher than the country's median salary of £24,000, according to Alzheimer's Research UK. And the social strain on the nation is only likely to get worse, doctors say. By 2021 they estimate that there will be more than a million people with dementia in Britain; by 2051 that figure will have reached 1.7 million. Furthermore, there will be fewer younger members in our ageing population to provide support for these incapacitated elderly people.
"The UK is not in the worst position, however," said Dr Eric Karran, director of research for Alzheimer's Research UK. "In China, where they have only allowed couples to have one child, there are even fewer younger people to look after the nation's ageing numbers.
"This is a crucial point. Alzheimer's is not, as some people claim, a disease of the developed world that is linked to western lifestyle. That is a myth; 60% of people with dementia live in the third world."
Dementia therefore threatens to engulf many nations. Hence the drive to find treatments – and the acute disappointment among scientists after the recent failures of several extremely expensive trials of drugs designed to slow the disease's progression. In July, Johnson & Johnson and Pfizer revealed that their drug bapineuzumab had failed to show benefits, and, in August, Eli Lilly said its solanezumab had also produced very disappointing results. Hundreds of millions of dollars had been spent on these trials, which had involved thousands of patients.
"There is no doubt the results were disappointing, but in a sense we should not be surprised by them," said Jeremy Hughes, the chief executive of the Alzheimer's Society. "Investment in dementia research is about an eighth of that for cancer research. Our understanding of what is going wrong in Alzheimer's is simply not strong enough as a result. Hence the failure of trials like these."
In May, David Cameron launched a campaign aimed at boosting funds of dementia research and increasing the numbers of young researchers entering the field.
However, Hughes sounded a note of caution. "Even if we doubled funding in this country, we would still only be spending £56m a year on dementia research – a fraction of the money spent on cancer research."
A major problem for doctors trying to deal with conditions such as Alzheimer's is that the disease may take 10 to 15 years before it manifests itself through early symptoms of memory loss and disorientation. By then, a significant portion of the patient's brain cells will have died.
"We need to find a bio-marker, a simple, low-cost test that will reveal if a person's neurones are beginning to die off," said Karran. "Then we can administer drugs that will halt the deaths of their brain cells. It would be the equivalent of a person being given a cholesterol test and then, if they have high levels, being prescribed statins to cut their cholesterol. In that way heart disease can be delayed for many years. That is the kind of thing we need for dementia."
The problem is that scientists have yet to develop a cheap, easy-to-administer bio-marker test that could pinpoint Alzheimer's patients in the early stages of their condition. Even if they had one, they have still to find a drug that can halt brain cell death. "We need both – a bio-marker and a drug to halt the death of neurones," said Hughes. "At present we have neither."
However, scientists stress that they have many promising lines of research. Most believe that Alzheimer's is triggered when a protein called amyloid beta builds up in the brain and triggers fundamental changes that eventually lead to the loss of neurones and the onset of the disease.
The drugs developed by Eli Lilly, Johnson & Johnson and Pfizer all target amyloid beta. Their failure has not dented scientists' belief that this is the cause of the condition, however. "It is still the best theory we have," said Lees.
"We are still hopeful," said Hughes. "For example, we are launching a new trial of drugs that have been used for other neurological conditions, such as Parkinson's, and we hope that we will find some promising medicines. And as these will have already passed safety and efficacy tests, they could be used on patients very quickly if found to improve their conditions."
In addition, detailed studies of Johnson & Johnson and Pfizer's bapineuzumab, which failed to produce improvement in Alzheimer's patients' memories and thinking, did reduce physical damage in their brains, a recent follow-up has discovered, suggesting that drugs such as these may still prove to be useful one day. "There are signs of hope, it is true, but we still have a long way to go," added Lees.