It is estimated that, by 2025, more than a million people in Britain will suffer from Alzheimer's. Its symptoms include memory loss, confusion and language breakdown, and it is incurable.
Is there anything individuals can do to avert this bleak prognosis? According to Professor Clive Ballard, the director of research at the Alzheimer's Society, and his colleague Dr Susanne Sorensen, the head of research, some simple changes to your lifestyle could delay and even prevent the onset of the condition.
"A large number of studies have shown that a number of factors may affect your chances of developing dementia, so it is never too early, or too late, to make a few changes," Ballard says.
Train your brain
When it comes to retaining brain agility, the "use it or lose it" principle holds true. Games such as Brain Age on Nintendo DS can help us to increase brain flexibility and activity, which some scientists believe can ward off the onset of Alzheimer's. But you don't have to invest in a gadget to give your mind a workout doing crosswords and reading challenging articles can cause synapse growth, which allows nerves in the brain to communicate with each other more efficiently.
A study in New York in 2003 found that those who did crossword puzzles four days a week had a much lower risk of dementia than those who did one puzzle a week. "The main evidence is in healthy older people, and it shows that 40 minutes a day can make a big difference," Ballard says.
There is good evidence that keeping fit can help to keep your brain in shape. A Swedish study showed that regular exercise can reduce the risk of developing Alzheimer's by 50 per cent. There appears to be a direct link between the condition of the body and that of the mind: a study published in the British Medical Journal found that obese people were 70 per cent more likely to develop Alzheimer's. Studies have shown that regular exercise improves the blood supply to the brain and benefits the entire cardiovascular system.
Ballard believes that a healthy lifestyle is an important step in the fight against dementia: "We recommend that people take regular exercise, eat healthily and get their blood pressure checked. People must be made more aware that what's good for your heart is also good for your mind."
Relieve the pain
According to a study by the University of Washington, cholesterol-lowering drugs may reduce the risk of developing Alzheimer's by almost 80 per cent. The drugs, known as statins, appear to reduce the tangles of plaques in the brain that are believed to cause Alzheimer's, but they might not work for everyone. In an interview with Medical News Today, the author of the study, Dr Gail Li, said: "Statins are probably more likely to help prevent the disease in certain kinds of people than others."
Studies have also shown that regularly taking painkillers such as aspirin could help, after population studies revealed a lower incidence of dementia in people with arthritis taking aspirin. The studies are encouraging but not conclusive, and Sorensen warns that there are risks involved in taking painkillers regularly. "We would not recommend taking aspirin as an effective way of reducing the risk of developing Alzheimer's," she says. "They can cause dangerous side-effects, such as kidney and liver problems and stomach ulcers."
Several studies have found that some anti-inflammatories, such as ibuprofen, can reduce the levels of abnormal proteins in the brain that lead to Alzheimer's. Because doctors are unsure why these drugs appear to reduce abnormal proteins, they warn against taking the drugs in the hope it will help prevent Alzheimer's, and say that more research is needed.
Work at your social life
Having plenty of friends is another factor. Scientists in the USE suggested a link between loneliness and Alzheimer's after observing a group of adults for four years. They found that people who spent more time on their own were more likely to develop the condition later in life. A study in Sweden found that people with extensive social networks were 60 per cent less likely to develop dementia than those living alone.
Leisure activities can have an effect on the health of our hearts and brains, and socialising with friends and family may protect your brain. Ballard says: "Some evidence shows that social interaction promotes better brain repair." One benefit of seeing friends may simply be that it gets you away from the telly; US scientists have suggested that sitting in front of the television for too long is harmful to brain health.
Just say no
Studies of mice have shown that one of the active ingredients in cannabis can block toxic proteins and reduce inflammation, two factors said to cause Alzheimer's. Don't be tempted to try this, however, as the cannabis derivative that appears to reduce the risk of developing the disease is not found in the form of the drug smoked by users.
Taking ecstasy can cause long-term brain damage, such as problems with learning and memory, and scientists fear this may lead to dementia later on. But "it's too early to tell", says Sorensen.
Ask your family
Work by the Alzheimer's Society has shown that the chances of inheriting the disease from a parent or relative could be moderately low. "We know that there are a small number of families where there is a very clear inheritance of dementia from one generation to the next," Sorensen says. "But, for the majority of people, the effect of inheritance seems to be small," she adds. If a parent or relative has Alzheimer's, your chance of developing it is only a little higher than if there were no cases in the family, the Alzheimer's Society says.
If both parents suffer from Alzheimer's, you could be twice as likely to develop the condition, according to a small study carried out in the USA in March. "It is clear that genes do play a role, but the largest risk-factor remains your age," Sorensen says. "One in three people over 65 will die with dementia."
Genetic testing for Alzheimer's is available in some countries, but not in the UK. Scientists believe that a test can only show an increased risk from one in five to one in four, and Ballard believes that testing would cause unnecessary worry. A National Dementia Strategy for England is due to be published by the Department of Health, in conjunction with the Alzheimer's Society, in October.
For more information on the dementia strategy, or about Alzheimer's, visit www.alzheimers.org.uk
Eat a healthy Diet
Eating a "Mediterranean diet" of vegetables, fruit and fish can cut your chances of developing the condition by 40 per cent, according to some studies. The diet contains high levels of vitamin C and antioxidants; these inhibit the production of free radicals, which can kill living cells. Some studies suggest that caffeine, and even dark chocolate, can prevent Alzheimer's and protect the brain from forgetfulness. "A diet full of green leafy vegetables, oily fish and the odd glass of wine is best for those who want to follow a diet that can help lower their chances of developing dementia," says Sorensen. Curcumin, found in turmeric and often used in curries, has also been found to have a protective effect. It appears to work by clearing harmful proteins from the brain that can lead to Alzheimer's. "Studies show that curcumin may protect nerve cells and thus reduce the risk of dementia," says Ballard. Certain vegetables that contain betacarotene, such as carrots, sweet potatoes and spinach, have also been shown to improve the health of the brain.