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July 20, 2003
Review: No fountain of youth here
THE author, Lawrence Whalley, is Professor of Mental Health at the University of Aberdeen. He works on molecular biology of ageing and Alzheimer’s disease (a neuro-degenerative disease). The book starts with a quotation of Winston Churchill who said in 1943 that the, “empire of the future will be the empire of the mind”. There is no doubt that brain research is a leading topic of science today and this book helps in understanding the progress that is being made.
Biology teaches us that once we have passed the reproductive age the body, including the brain, begins to decay as we become irrelevant for the survival of the species. This is true of all forms of life, from bacteria to humans. The only recourse we have is to try and delay ageing and remain as healthy as possible until death. This is the message which the author conveys through this book.
The Ageing Brain has 11 chapters, and a useful list of publications at the end, for further reading. The earlier chapters deal with the anatomy of the brain and theories about ageing. The later chapters discuss the diseases of the brain associated with old age, particularly dementia and Alzheimer’s disease.
In the beginning, the book has an amusing story of how the widely used retirement age of 65 was arrived at. Apparently, this is a creation of Germany’s Chancellor Bismarck, who when pressed to pay pensions to war veterans reluctantly agreed. The officials then inquired at what age should the veterans become eligible for their pension? Bismarck asked how old are they likely to be when they die? Around 66 was the reply. “Then give them the pension at 65” he retorted. For Bismarck’s time this was a clever move, but with the European life expectancy now close to 80, the pensions are driving some European governments into bankruptcy!
The brain, claims the author, is the most complex structure in the known universe. Weighing about 1.5 kg it comprises about 100 billion brain cells each making on an average 10,000 connections with other brain cells. The network of brain cells organize themselves to do specific tasks. Experience and learning can alter these connections, their numbers and shape. The ability of brain cells to do this is sometimes called the “self-organizing principle”. No existing computer can do this, although in the performance of specific tasks, for instance, calculation computer can perform better than any human.
The brain like the rest of the body suffers wear and tear with age due to environmental factors. To some extent these are in our control and preventable. On the other hand there is a genetic component, with an inbuilt cellular senescence and propensity to certain illnesses which cannot be rectified. Similarly, genetics play a major role in mental abilities and their retention up to the old age, as studies done on twins show.
Previously it was thought that there is no regeneration in brain cells. This is now proven to be incorrect and some cells of the brain can regenerate. Also, the function of the damaged cells can be taken over by the neighbouring undamaged cells which means that limited brain damage is not always disastrous.
To keep one’s brain healthy the author recommends mental activity, physical fitness, exercise, reduced stress, balanced diet, socialization, minimal alcoholic intake and no smoking. The author reminds us that good health during pregnancy, childhood and adult life also leads to a healthy old age.
The same factors that predispose to cardiovascular, respiratory and other systemic diseases adversely effect the brain as well. The brain is especially vulnerable to diminishing blood supply as it happens for example, in atherosclerosis and other vascular diseases.
The brain cells talk to each other all the time and this occurs through connections called synapses. The synapses are separated from each other by a gap of about 10-20 mm. Chemicals known as neurotransmitters allow the passage of impulses through this gap. An important neurotransmitter is a chemical called acetylcholine. In the ageing brain, especially in Alzheimer’s disease, acetylcholine is reduced, therefore neural transmission is impaired. This results in mental slowing and varying degrees of memory loss. Acetylecholine is destroyed by an enzyme called acetylcholinesterase, which keeps the level of acetylcholine in proper balance. To raise the level of acetylcholine in Alzheimer’s disease, drugs are given which prevent the breakdown of acetylcholine.
These do not cure the disease but provide partial relief of symptoms. The ageing brain is vulnerable to nutritional deficiencies particularly folate and Vitamin B12. Essential fatty acids play a key role in the formation of cell membrane and fish oils, which contain essential fatty acids, are useful as a dietary supplement. Selenium and Zinc are trace elements which are needed by the brain and their intake is also recommended.
Two drugs, Statins (used for lowering blood cholesterol) and non-steroidal anti-inflammatory drugs (NSAID) appear to have some beneficial effect in the prevention of dementia and Alzheimer’s disease. However, these findings need to be confirmed before their use could be recommended. Hormone replacement therapy (HRT) in menopausal women was also regarded as beneficial for the ageing brain but the latest data, which is not in the book, (JAMA 2203; 289: 2651-62) shows an opposite effect. It appears that women on HRT face twice the risk of developing dementia to women who are not on HRT. In short, there is no fountain of youth which can keep old age in abeyance.
Commonsense measures which keep the body healthy also keep the brain in good shape.
The Ageing Brain
By Lawrence Whalley
Phoenix. Available at Paramount Books, 152/O, Block 2, PECH Society, Karachi-75400
Tel: 021-4310030.
Email: paramount@cyber.net.pk
ISBN 0-75-381-361-0
246pp. Rs545
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