The Government is rumoured to be considering raising the retirement age to 70 in an attempt to reduce the national debt — plans that will have been given a useful fillip by new research that reveals postponing retirement can delay the onset of Alzheimer’s disease.

According to researchers from the Institute of Psychiatry, at the Maudsley Hospital, southeast London, every extra year worked delays the onset of dementia by just over a month. So working until you are 70 instead of 65 is likely to give you an extra six Alzheimer-free months. I am not sure that is enough of a benefit to warrant the additional effort, but extending your working life is not the only thing you can do to protect yourself.

One person in 20 over the age of 65 in the UK has some form of dementia. Alzheimer’s disease — characterised by a loss of brain cells, shrinkage and protein deposits forming tangles and plaques throughout the brain — may be the most common form, but it is not the only one. Gradual furring up of the arteries supplying the brain accounts for at least 20 per cent of cases and causes similar impairment to Alzheimer’s with resulting loss of memory and cognitive ability, disorientation and confusion. And, while there isn’t much we can do to slow the progression of Alzheimer’s disease, there is a lot that can be done to keep our brain and its circulation healthy — and the healthier your brain the less noticeable any deficit is going to be.

Use it or lose it. The brain is often compared to a muscle in that “exercising” it can slow the damage time brings, and challenging yourself mentally every day will help to keep you sharp. The latter can include hobbies, keeping up an active social life, learning new skills, doing crosswords and puzzles and brain-training games and, as the recent research has shown, working for longer. The brain is made up of around 100 billion nerve cells, each connected to thousands of others through synapses and it is a decrease in this interconnectivity, rather than the loss of brain cells alone, that is responsible for the slowing of mental agility that occurs with advancing years. Challenging the brain is thought to help by maintaining existing synapses and encouraging the formation of new ones.

Look after your head. Dementia is much more common in people who have had severe or repeated head injuries. This is the origin of the “punch drunk” syndrome in some boxers. Blows to the head can lead to an over-production of a protein called beta-secretase, which accelerates the formation of the characteristic plaques found in someone with Alzheimer’s. So wear a helmet when cycling or doing dangerous sports — and stay out of the boxing ring.

Look after your heart. The same risk factors that damage your coronary arteries will fur up the blood supply to your brain and accelerate dementia. What’s good for the heart is good for the brain so don’t smoke, eat a healthy diet, exercise regularly, keep your weight down and watch for hazards such as high blood pressure, raised cholesterol levels and diabetes.

Have regular blood pressure checks. At least every three years once past the age of 35, and every 12 months if borderline (over 140/80) — because high blood pressure is toxic to the delicate brain.

Get your cholesterol level tested. Particularly if there is a family history of early stroke or heart attack — and follow advice to reduce it if it is raised (including taking cholesterol-lowering statins if required).

Check for diabetes. Ask the nurse at your doctor’s surgery for a blood test if you suspect diabetes — clues include a great thirst, peeing more than normal, recurring infections such as boils or thrush, lack of energy and blurred vision. Those most at risk include the overweight, anyone with a family history of the condition and those of Asian and Afro-Caribbean origin.

Drink in moderation. While sensible drinking — the equivalent of two or three small glasses of wine on most days for a woman and three to four for a man — can protect against some forms of dementia, heavy drinking has the opposite effect. One recent review suggests that alcohol accounts for at least 10 per cent of all UK dementia cases. You don’t have to be middle-aged or elderly to be at risk: there is evidence that heavy drinkers in their thirties and forties already have significant memory impairment.

Eat oily fish. Fresh tuna and tinned salmon, or fish oil capsules, may protect against Alzheimer’s disease and improve brain function. The exact mode of this protection is now under investigation, but it is thought that the omega-3 fatty acids in fish oils may slow the formation of plaques — an effect that may be enhanced by fatty acids also seeming to protect the delicate lining of the arteries supplying the brain, thus helping to maintain good blood flow. One American study found that men and women eating at least one portion of fish a week were half as likely to develop Alzheimer’s as those who didn’t eat any.

But the case is not so strong for another popular brain supplement. It is thought that as many as one person in ten with dementia is now taking ginkgo biloba despite the latest evidence, which suggests that, while the herb may boost blood supply to the brain, this doesn’t translate into any significant benefit.

Consider hormone replacement therapy (HRT). Women who take HRT have been shown in a number of studies to be less likely to develop Alzheimer’s disease later in life. But HRT has no impact on the progression of the disease once a woman develops the condition. Bottom line? It is a useful side benefit, but concerns about Alzheimer’s disease on their own are not a strong enough indication to prescribe HRT in women who are not having menopausal symptoms.

For advice on Alzheimer’s disease visit: www.alzheimers.org.uk