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Mind Gains
By Margaret McCartney
Published: March 10 2006 14:12
My friend Joyce walks six miles a day, unless the weather is rotten:
then she does just three or four. In the summer she likes to do a bit
of tai chi in the park. She's a voracious reader and contributes to
various philosophical e-discussion groups. Joyce is in her 70s and is
one of those people whose life, far from becoming empty in retirement,
has filled almost to overflowing. Keen to speak to her for this piece,
I found I had to leave several phone messages and send a number of
e-mails: she is always busy.
I hope I am like Joyce when I reach her age: fit and, perhaps even more
important, mentally sharp and lively. Thanks to medical science, we now
expect our bodies to be reasonably preserved into our seventh and
eighth decades. The new, tantalising, holy grail is to be able to
preserve the health of our brains as well.
With life expectancy increasing, many fear an old age spent confused
and bewildered, unable to recognise loved ones. The way in which
dementia affected academic and author Iris Murdoch touched a nerve.
Neurones are business now. We are told that our offspring will be more
intelligent if they listen to special recordings of Mozart for babies,
study black and white flash cards or take fish oil supplements that can
have near-miraculous effects on the brain. This weekend, the BBC1 is
broadcasting Get Smarter in a Week, which promises to show us how a
combination of puzzles, switching handedness and sensory deprivation
(for example, showering with your eyes closed) can make you up to 40
per cent cleverer.
This might make for good television but how much can we really boost
our brain's functioning? Is it possible to prevent, slow or even stop
illnesses such as dementia?
Ian Robertson, Professor of Psychology at Trinity College, Dublin, and
author of Stay Sharp with the Mind Doctor (Vermilion, £8.99),
believes it is. In a lecture to the British Association for the
Advancement of Science's Festival of Science in Dublin last year, he
said that not only is it possible to slow the effects of age on the
brain but that diet, exercise, mental stimulation, mental training and
stress were all "key factors in determining whether your brain can stay
healthy enough for you to enjoy life in the new prime between 50 and 80
. . . Hearts and livers can be repaired and transplanted, many cancers
can be cured or tamed. With good food and the best therapies, the
biggest remaining obstacle to long life is the fitness of the brain and
mind."
Researchers are hard at work studying the effects of the possible
neurological anti-ageing treatments Robertson cites. But first there is
some good news if you are highly educated and work in a stimulating
job. There appears to be a relationship between education level and
subsequent cognitive decline: "There is circumstantial evidence that
levels of education are related to the richness of connections between
brain cells - in other words, learning is associated with making
increased synapses [or connections] between the parts of the brain.
This does seem to be protective against decline," explains Robertson.
He continues: "There is a very strong association between mental
challenge in your job and lower levels of cognitive decline in ageing."
Mental challenge continues to be important after retirement. When I
wrote about the health effects of retirement in my column on the health
page a few months back, many Financial Times readers wrote to me with
tales of how they had taken up impressive challenges in retirement,
such as studying for a degree or learning a language. As one
correspondent put it: "If I didn't keep going, I think my mind would
just seize up and stop working".
An experiment in the US, co-ordinated by the Johns Hopkins University
in Baltimore, showed how mental challenge improved quality of life for
older people not in employment. The researchers recruited an
"experience corps" of older people who also tended to be socially
excluded to take a course in literacy support. They then became
volunteer assistants in schools. When they were followed up, after
between four and six months, not only had the volunteers' cognitive
function improved but their walking speed and social networks had
increased too. (The teachers also reported that the children were less
disruptive and that their reading had improved.)
However, the strongest of all associations for maintaining cognitive function as people get older is undoubtedly exercise.
My friend Joyce is a great believer in her regular exercise. If she
doesn't get it, she says, her head suffers. It seems her instincts are
right. Physical health and brain health go together.
A study published in the Journal of the American Medical Association in
2004, (part of the enormous US Nurse's Health Study, which followed
almost 20,000 women over 20 years) found that the women who were most
physically active - "walking at an easy pace for at least 1.5 hours a
week" - scored higher on scores of general cognition, verbal memory,
mental sorting and attention than those who walked for less than 40
minutes a week.
But does this translate into less confusion or dementia in old age? It
seems it does. Part of the FINE (Finland, Italy and the Netherlands
Elderly) study was published last year in the journal Neurology. Almost
300 men born between 1900 and 1920 were assessed for physical exercise
and cognitive functioning, starting from 1990. After following the
group for 10 years, the researchers concluded: "Even in old age,
participation in activities with at least a medium-low intensity may
postpone cognitive decline. Moreover, a decrease in duration or
intensity of physical activity results in a stronger cognitive decline
than maintaining duration or intensity." In other words, letting your
exercise slip because of your age is a bad idea.
Other findings suggest that it is worth getting into the habit of
exercising early on. A study published in The Lancet Neurology last
October showed that those who exercised twice a week in midlife reduced
their chances of being diagnosed with dementia and Alzheimer's disease
about 21 years later, when compared with people exercising less often.
This association remained even when the figures were adjusted for
education, smoking and alcohol use.
In the Honolulu-Asia Ageing Study, after adjustment for age, retired
Japanese-American men who walked little (less than 0.25 miles, or
0.40km per day) had a 1.8 times increased risk of dementia compared
with those who walked more than two miles (or 3.2km) per day.
The evidence is convincing: exercise does appear to protect and preserve neurological function. But how does it work?
Dr Art Kramer, a psychologist and neuroscientist at the University of
Illinois, published the result of a series of experiments in
Proceedings of the National Academy of Sciences USA in 2004, in which
he and his colleagues showed that brain structure changed in response
to exercise. What is more, these changes occurred in older brains,
which are generally thought of as less malleable.
Magnetic resonance imaging brain scans were run on 60 people aged
between 58 and 77. Those who did aerobic exercise or increased their
amount of aerobic exercise, experienced change in the prefrontal and
parietal parts of the brain. This type of scan not only shows
structural changes - in this case, an increase in substance of the
brain areas concerned with memory and attention, which are also the
areas that show the greatest age-related decline in humans - but also
the altered function of the brain. Kramer and his colleagues found
aerobic exercise had also increased the activation of several brain
areas concerned with "attentional control", believed to be crucial in
memory and cognitive function.
It is thought that these changes are at least partially due to a
chemical - a "brain-derived neurotrophic factor" - that is stimulated
by physical exercise. This chemical may improve existing neurological
connections and lead to the growth of new ones. It may even lead to the
creation of new cells.
There is at present less evidence that mental exercises, such as sudoku
or crosswords, can bring about similar changes but the research is
beginning to suggest that they might.
MRI scans have shown that taxi drivers learning "The Knowledge", the
routes in London within a six-mile radius of Charing Cross, actually
"grow" part of their brain - the hippocampus - in response to the
challenge. A study in the New England Journal of Medicine in 2003 found
that the risk of dementia was lower in people aged over 75 whose
leisure activities included reading, dancing and the playing of board
games or musical instruments.
Another study in the Journal of the American Medical Association in
2002 used different types of "brain training" - for speed, memory and
reasoning - in people aged between 65 and 94 and found that all methods
improved cognitive function both immediately and at a follow-up test
two years later.
Research done by the Alzheimer's Disease Research Center, in Washington
St Louis, has also found in preliminary studies that the parts of the
brain used for daydreaming - in what the resear chers call "default"
mode - are the areas most affected in Alzheimer's disease. They
speculate that activities such as crosswords and exercise could
increase activity in the parts of the brain that are less likely to be
damaged by Alzheimer's, such as those areas that deal with memory.
It is possible then that your daily crossword stimulates some areas of
your brain so that they are able to "take over" if other parts became
damaged by processes such as dementia. As the researchers conclude:
"Cognitive idleness is not good from the perspective of Alzheimer's
risk."
Meanwhile, diet remains a tantalising possibility in terms of brain
functioning. It seems that when our mothers told us that fish is "brain
food", they were not far off the mark. The well-publicised Durham
trials (www.durhamtrial.org.uk) took pre-school and primary school age
children identified as having difficulties in learning or concentrating
and randomised them to receive either fatty acids or identical placebo
capsules. Halfway through, the medication was "switched". The study was
large and impressive, requiring more than 12,000 assessments with the
involvement of teachers and parents. The fish oils did not help all the
children but about 40 per cent did become better at concentrating and
their reading ages leapt during the course of the trial.
By standard medical gains for treatments, this is a pretty good result,
and sales of Omega-3 supplements have shot up as a result. There is
even an Omega-3 enriched "clever milk" on the market. (It is worth
noting, though, that you would have to drink an awful lot of milk to
get to the quantities of Omega-3 used in the research, which were six
capsules of fish oils of a rather different composition every day -
which works out, for the Omega-3 component, at about three times what
you would get in two large glasses of "clever milk".)
Many of these (expensive) supplements are being given to children with
no learning or concentration difficulties, and I know quite a few
parents who dip into their kids' supply.
Is there any evidence that what works for children works for adults
too? Not yet, and further research is still being done on the effect of
Omega-3 work on children with no specific problems and on
secondary-school-age children.
Yet there is little doubt about exercise. The evidence is clear that
exercise - both physical and neurological - can help reduce the risks
of dementia, and studies of diet may one day yield results.
Even so, reducing a risk is not the same as eliminating it. Dementia
may still claim us and we should never blame ourselves or others for
illnesses that could not have been prevented.
I finally heard back from Joyce. It turned out that she had been away
hill-walking. "Exercise probably does keep my mind healthy," she told
me "but, actually, I do it because I enjoy it." That, it seems to me,
is the key. We need to look holistically at the way we live our lives.
Talking to researchers, the striking thing that comes out is that the
more life in our lives, the better.
I have to admit that researching this feature pushed me not only to
join the gym but to start actually going to it. If this paves the way
to better mental functioning when I am older, I would see that as an
added bonus, for the immediate benefits of exercise are so pleasurable
in themselves.
I could say the same for reading, good conversation and the (attempted)
brushing up of my school French. I remain useless, however, at
crosswords and other word puzzles and I shan't put myself through the
agony of trying to do them just because they might have certain
beneficial effects on my brain. Better, it seems to me, to live life
fully, using and enjoying all our faculties as best we can.
Tonight Joyce is out playing bridge. She has asked if I'd like to learn. I think I will go along.
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