2010-07-03 04:59:09
You cannot alter your age or the genes you are born with, but there are
lifestyle changes you can adopt which may reduce your chance of developing
dementia by as much as 20%.
The BBC convened a panel of independent experts, chaired by the Alzheimer's
Society, which evaluated more than 70 research papers and articles to come up
with a series of tips for reducing your risk.
It may sound young, but the age of 35, they suggest, is high time to start
thinking about these recommendations. If more of us acted on these, thousands
of cases of dementia could be prevented in the future.
There is very strong evidence for the following:
EXERCISE
Prof Clive Ballard gives his top tips on how to cheat dementia
What is good for the heart is good for the brain. Exercise can have a
beneficial effect at any age to help protect against dementia. To help reduce
the risk at least 30 minutes of exercise, five times a week is suggested. It
does not have to be the gym - a brisk walk is a perfectly acceptable
alternative. Whatever form of exercise gets your heart pumping and leaves you
somewhat out of breath is doing the trick. Exercise helps maintain a healthy
weight and blood pressure, and so is indirectly thought to reduce the risk of
dementia.
There is also growing evidence that regular exercise has other health effects
such as promoting cell and tissue repair mechanisms including growth of new
cells in the brain.
NOT BEING OBESE
Being seriously overweight is deemed a risk factor for developing dementia.
This really matters in mid-life - between the ages of 35 and 65. Obesity
increases the likelihood of developing Type 2 diabetes - believed to be a risk
factor - but whether this causes the disease, or is simply more likely to
develop in those who are also more prone to dementia is unclear. Obesity is
also associated with higher cholesterol and blood pressure - again, known to be
risk factors. You are deemed clinically obese - very overweight - if you have a
BMI of 30 and above.
Check your BMI here with our calculator
BRING DOWN HIGH BLOOD PRESSURE
BBC Panel
The panel evaluated more than 70 research papers
Again, the key here is having consistently raised blood pressure in mid-life -
anything above 140/90mmHg. It is thought that this increases the chance of
dementia by causing damage to the brain. This may happen as a result of a
stroke - in which blood supply to part or all of the brain is cut off - or due
to microvascular disease, a condition which slows the flow of blood through the
body thereby damaging cells and nerves in the brain. If you are over 40, or
have a history of dementia or cardiovascular disease in your family, then get
your blood pressure checked regularly.
REDUCE CHOLESTEROL
It is mid-life levels once more which appear to pose the greatest problem. Like
high blood pressure, high levels of cholesterol raise the risk of stroke and
microvascular disease. But cholesterol is also thought to be involved in the
mechanism which causes amyloid protein plaques - the protein deposits that
characterise Alzheimer's disease - to build up. Again if you are over 40 or
have a family history, get your cholesterol checked. The Department of Health
recommends a total cholesterol level of less than 5.0mmol/l.
NOT SMOKING
This had been an area of confusion, as some studies had suggested nicotine
could have a protective effect - with the chemical reducing plaques when
administered to animals in water. But the way in which we smoke tobacco, and
the other chemicals inhaled in the process, negates this benefit. As well as
raising the risk of vascular disease - a risk factor for dementia - smoking can
result in low oxygen levels in the brain which in turn can promote the
production of the protein found in brain plaques.
It is possible the following may have an impact:
ALCOHOL
Alcohol
There is no need to start drinking if you do not already
In fact the studies are quite clear that drinking a modest amount appears to
protect against cognitive decline. Moderate drinking is defined as keeping
within the recommended daily limits - up to two small glasses of wine for a
woman, and three for a man. The problem is that these studies compare drinkers
with non-drinkers - and people who abstain may do so for health reasons, which
in turn may affect their chances of developing dementia. The message is if you
are drinking within your weekly guidelines there is no need to stop, but there
is no need to take up drinking or increase the amount you consume, as heavy
drinking may in fact increase your risk.
FOLLOWING A MEDITERRANEAN DIET
Several recent studies have highlighted the potential for this diet to reduce
the risk of Alzheimer's Disease. It involves eating lots of fruit and
vegetables, whole grain foods, fish and plenty of olive oil, but it is
relatively low in dairy products and processed foods. Further long term
research is needed to confirm the effects of eating this way.
BEING SOCIALLY ACTIVE
Some evidence suggests that an active social life throughout life can be
protective, with both the social ties one enjoys with others and non-physical
leisure time deemed important. However, examining these factors and designing
studies which can separate their effects is very difficult - consequently the
conclusions which can be drawn from results are limited. One particular study
has found that being single and living alone is a risk factor for dementia:
social isolation is thought to have negative effects on health generally,
increasing depression and cardiovascular disease.
Studies have also suggested that engaging in non-physical leisure activities
such as gardening, and knitting may have a protective effect, a benefit that is
likely to accumulate gradually over decades.
But the jury is out on:
BRAIN TRAINING
It sounds both attractive and plausible that giving your brain a "workout"
could guard against dementia, and there is some evidence that very intensive
brain training under strict conditions can improve specific functions like
reasoning and problem solving. But there is no evidence as yet that doing a
crossword a day or a number puzzle - or even learning a new language at 50 -
will protect against dementia. That does mean they do not - simply that the
proof that they do is presently lacking.
VITAMIN SUPPLEMENTS
There is no consistent evidence either way as to whether B vitamin supplements
- folic acid, vitamin B12 or B6 - are effective in reducing the incidence of
dementia. Research continues. However vitamin E supplements, which it was once
hoped could prevent and even reverse early neurodegenerative changes, have not
appeared to be effective in trials.
The panel comprised of Professor Clive Ballard (Chair), Director of Research,
Alzheimer's Society, Dr Sarah Aldred, University of Birmingham, Dr Jacqueline
Birks, Cochrnae Review, Oxford, Professor Carol Brayne, Institute of Public
Health, University of Cambridge, Professor Mia Kivipelto, Karolinska Institute,
Sweden, Dr Marcus Richards, Medical Research Council, Professor John Starr,
Royal Victoria Hospital, NHS Lothian, Professor David Smith, Founding Director
OPTIMA, University of Oxford, Professor Raj Kalaria, University of Newcastle