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Association of British Science Writers
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These pages were designed, well, cobbled
together, by Michael Kenward on behalf of the ABSW.
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Ageing: science, medicine and society*
Biological ageing
Evolutionary strategies
Genes
Neurology
The ageing of populations
Social trends
Family structures
A healthy old age?
Self-help
The ageing of individuals
Memory
A Grandparent Commission
Accommodation
Quality of life
Resources and policy implications of ageing
Pensions and benefits
Role of health services
The new future
Summary
Average life expectancy in industrialised countries now stands at 75, with women living seven or eight years longer than men. For most of their history, humans have lived, on average, a mere 40 or 50 years: a lifespan heavily influenced by deaths in infancy. It is only in the last 50 years, when improvements in health care have enabled more people to survive into adult life, that we have seen an acceleration in longevity and an increasing proportion of old people in the population. But these startling advances have a downside: a rise in disability and chronic diseases, the most prevalent of which is Alzheimer's disease. Why prolong life if the extra years are to be spent in misery or dependence? The World Health Organisation's statement - "Health expectancy is more important than life expectancy" - has never been more apt.
Governments are as eager as their people to increase health expectancy because of the cost of health care for an increasingly long-lived population. They are also keen to find politically acceptable ways of paying for pensions.
Even though the meeting encompassed unusually diverse presentations, some themes emerged. One was a plea for medical researchers to look further than their specialisms - cardiovascular disease, diabetes, autoimmunity, etc - to realise that they are all studying different aspects of gerontology, a field which needs more recognition and support. Another theme was the need to enable the elderly to make retirement a challenging and fulfilling time of life, and the ways in which this might be done through intellectual and physical activity, social and financial support, lifestyle, housing and health care. As for judgements about quality of life, however, these are subjective and must be left to each person individually to decide.
* Summary of a joint Royal Society and British Academy discussion meeting held on 7 and 8 May 1997
Biological ageing
Dr Robin Holliday of the CSIRO Division of Biomolecular Engineering in Sydney, gave a broad overview of the biology of ageing. Multicellular animals have two types of cells: germ cells, which go on generation after generation, and somatic or body cells. There are two basic strategies for survival. Either the animal puts energy into regeneration and repair of its body, so it can go on indefinitely, or it puts energy into early reproduction in which case its body will age and die. Most animals have evolved the latter strategy, which produces more offspring to survive to the next generation. Although there is good evidence that body maintenance is more efficient in longer-lived animals like humans than in those that live for shorter times, we age because our maintenance mechanisms eventually fail and we cannot replace essential parts of ourselves when they go wrong (for example brain cells, heart muscle, major nerves and blood vessels). Any discussion of ageing must therefore take into account all the ways in which we maintain our bodies: DNA repair, immunity, wound healing, defence against free radicals, etc. Researchers studying the changes at cellular level, and the pathologies these give rise to, are actually studying ageing. The specialisation of researchers in these areas masks the fact that they are all studying aspects of gerontology, which ought to be given more recognition and support.
Evolutionary strategies
Professor Tom Kirkwood of the Biological Gerontology Group at the University of Manchester described human ageing in the context of comparative and evolutionary biology. Although humans show a steadily increasing death rate with advancing age, there is nothing inevitable about this pattern. Fresh-water hydra, for example, do not. Most animals, however, do age for two reasons. The first is that because animals in the wild do not generally survive predation to live into old age, natural selection has only limited opportunity to affect events which happen late in life. This means that any mutations or changes harmful in later life can accumulate in the genome practically unchecked by natural selection, and their effects finally age the whole organism. The second is that to reproduce many offspring early on in a lifespan is a better survival strategy than to reproduce at a constant rate throughout life. Early reproduction, however, uses up so much energy that animals which follow this strategy do not have as much to expend on maintaining their bodies, so they sacrifice their chances of longer lifespans.
Humans have evolved the longest lifespans of any mammalian species because our brains have enabled us to reduce the risk posed by our environment. Menopause seems to be a paradox: it shuts down reproductive function when a woman is still capable of bearing children. However, it enables the older woman to contribute to the survival of her grandchildren - and thus her genes.
Genes
Genetics can help us understand ageing, and this was the subject of the presentation by Professor George Martin from the Department of Pathology, University of Washington in Seattle, USA. Although genes are currently thought to be responsible for only 30% of longevity, and the environment for 70%, genes lead us to fundamental mechanisms. People who have aged particularly successfully may owe this to genetic factors, and these should be investigated. Candidate genes would be those which have early benefits but bring late disadvantages; for example a gene which is a receptor for testosterone. Certain forms of this receptor are more responsive to testosterone than others. A greater response might give a selective advantage in the form of a more muscular, competitive individual with stronger bones; but individuals with this form of the gene pay a price of a higher likelihood of virulent prostate cancer later in life. Other genes to look for would control late-onset degeneration or inappropriate proliferation of cells which could lead to malignancies, or which modulate common mechanisms of ageing.
Neurology
The ageing process in the brain was described by Professor Brian Anderton of the Department of Neuroscience at the Institute of Psychiatry, London. Healthy brains lose volume and weight and up to 50% of their nerve cells (neurones). The long extensions of the nerve cells and the regions in which a message is passed from one to another, proliferate in an attempt at compensation. These changes are the same as, but less severe than, those seen in Alzheimer's brains, which also show characteristic senile plaques and neurofibrillary tangles. The senile plaques are outside cells, and the protein amyloid is in the plaque cores and around them. The relationship between plaques and tangles is not clear. The tangles, made of tau protein, are inside the nerve cells and develop in a regular pattern throughout the brain. They disrupt the transport of messages from one nerve cell to another. The cells atrophy and die, and dementia results.
Early-onset Alzheimer's disease is genetically determined: it is caused by mutations in three known genes, and a gene which makes a protein called APOE e4 is a risk factor. APOE e4 is 2.5 times more common in Alzheimer's patients than in the general population. There is probably also a genetic component to late-onset Alzheimer's disease, but that is not related to the three known genes. There are also environmental risk factors for Alzheimer's disease, such as head trauma.
The ageing of populations
Professor James Vaupel, Director of the Max Planck Institute for Demography at Rostock in Germany, challenged the view that health care should not be wasted on hopeless attempts to prolong life in old people. This attitude is pernicious because it leads to too little expenditure on both health care for the old and research into diseases of the aged. In fact, both women and men - but especially women - in Europe and Japan are living proof that lifespans can be longer than we have assumed. They are living longer, and the pace of increased longevity is accelerating. White Americans over 80 have lower death rates than their contemporaries in Western Europe or Japan, which may be because of the benefits of US medical care. This is further evidence for the plasticity of mortality at old ages.
Professor Vaupel's nature/nurture estimates were that 25% of the variation in human lifespans is caused by genetic factors; another 25% by factors such as class, education, diet and behaviour, which are fixed by the age of 30; and 50% by short-term factors (like standing in front of a truck!).
Social trends
Increased longevity will have profound effects on society. These were addressed by Mr Peter Laslett of the Cambridge Group for the History of Population and Social Structure. The ageing of populations of industrialised countries has been brought about not because of the fall in mortality but because of the fall in fertility. Contemporary Europe has the lowest fertility of any continent. Western and Japanese populations are uniquely old, and have become so during the 20th century. The consequences for our economic and social structures are quite radical and will become more so. Fewer young people will mean fewer resources to support the old. The family is developing a "beanpole" structure: a string of lineal descendants stretching over at least three generations but with few siblings or other lateral relatives, although - in Scandinavian and Anglo-Saxon countries - with rapidly increasing numbers of step-kin. Women now have an average of 31 years after retirement, and men, 26; and the extra time given by this Third Age will have to be spent constructively.
The new scientific, engineering and design activity named gerontechnology could do a great deal to maintain elderly people's mastery of their environment. The ageing transformation could put an end to unemployment and create a more civilised society.
Family structures
Social insurance systems will come under severe strains as populations age, and Professor Ken Wachter of the Department of Demography, University of California at Berkeley, argued that one solution might lie in step-kin offering more support to the elderly. Demographic predictions forecast decreasing numbers of biological children and grandchildren, and show step-children increasing as a proportion of grandchildren. Although the ties between step-kin are not as tight as those between blood relations, there will be numerous step-kin in the new family grouping so that elderly people may well become close to one step-relative. The new kinship networks are expected to include members of different races and classes, and may increase social cohesion.
A healthy old age?
Support in old age is an increasing problem for industrialised societies. Longer life brings a penalty in chronic disease, disability and dependence. Dr H.P. van de Water of the Division of Public Health and Prevention, TNO Prevention and Health at Leiden in the Netherlands, forecast this future for an increasing number of people, especially women. Although women in the Netherlands live longer than men, they endure more ill-health at the end of their lives. We can already see that fatal illnesses like cardio-vascular disease are being substituted in old age by non-fatal conditions like dementia and arthritis. This change is poorly understood and not generally taken into account in medical trials, but it may thwart our expectations for a healthy old age and it is important that policy-makers in public health understand it. We should change our current disease-specific approach to thinking of health as a whole.
Self-help
Professor Kay-Tee Khaw of the Department of Gerontology, Addenbrooke's Hospital, Cambridge, spoke about the degree to which disability in old age can be prevented. There are great geographic variations in the rates at which old people develop major chronic disease such as stroke, coronary heart disease, cancer and cataracts, which suggests that these conditions are not an inevitable part of ageing. As well as genetic predispositions, there are extrinsic factors such as nutrition, physical activity, smoking, environmental hazards and psycho-social factors (stress, for example). Current evidence suggests that giving dietary supplements to humans does not reduce mortality whereas changing to a Mediterranean diet does. Interventions can also reduce the incidence of osteoporosis and hip fractures. There is huge potential for life-style interventions to prevent age-related disability, and we need a better understanding of what factors influence which conditions so that we can, as far as possible, determine our own healthy ageing.
The ageing of individuals
Professor Archie Young of the Department of Geriatric Medicine at the Royal Free Hospital in London, described how we lose tissue (muscle and nerve cells, for example) as we age. A study of very healthy old people showed this inevitable deterioration in the power they could generate by a single thrust of a leg. The study also showed that, at any given age, men outperform women; and again at any given age, there is considerable variation between individuals within each gender. As muscle power decreases, it approaches a threshold at which a particular task (for example managing a low step) becomes impossible. Not only muscle, but also bone mass and organs such as livers and kidneys lose volume with age, and the same sorts of thresholds apply. Old people do not notice the loss until the threshold is reached, when catastrophic consequences (for example a broken hip) follow from an ordinary situation (for example falling on ice). The tissue remaining is, however, normal and responds to strength-training. It ought to be possible to improve health in old age by increasing physiological function, reducing its rate of decline or lowering the threshold at which disaster strikes. Discussants told the meeting that houses (with stairs) may well be better for old people than bungalows - and also that the elderly prefer bungalows!
Memory
Professor Deborah Burke of the Department of Psychology at Pomona College, California, described the effects of ageing on memory and language. Memory declines for new, episodic information such as where we put our keys or putting names to faces. Young people perform better on these tests than old people do. In order to remember episodic information we have to form a new connection in the memory between the new information and the context in which it arose, and this becomes increasingly difficult. The age deficit in episodic memory contrasts with performance in using existing memory: our vast store of information about the world and about language. Vocabulary is constant well into old age, as is detection of spelling errors and word associations. One exception to this is the "tip of the tongue" phenomenon, in which access to particular forms (especially proper names) of words is impeded.
In one experiment which encapsulates what we lose and what we retain with age, old and younger people were shown an end-game in chess and asked to evaluate the state of play. The quality of their evaluations depended not on their age but on their chess skill. However, when they were later asked to recall the layout of the end-game, the younger participants were able to remember more than the old ones.
There are several theories which try to explain these observations, and in developing a sound theory it is important to consider both what is spared as well as what is impaired. However, the general lesson with cognitive ability - as with all others - is that we must use it or lose it.
A Grandparent Commission
Although old people do lose certain abilities, they retain others and still have a great deal to offer to other people and society at large. Lord Young of Dartington, Director of the Institute of Community Studies, argued for the setting up of a Grandparent Commission to bring to national attention the role grandparents have in protecting children especially while parents are at work or when marriage breaks down. In spite of current warnings about the effects of divorce and working women on the future of the family, the picture could change if grandparents were to play a more supportive role. The contribution grandparents can make ought to be recognised and provided for by the Government, and anomalies abolished. At the moment, for example, families with dependent children who claim family credit are given financial assistance if child-care is provided by professional child-carers, but not if grandparents look after their grandchildren.
Accommodation
Whether the elderly are able to nurture and use their abilities depends to a large extent on their environment. Professor Anthea Tinker, Director of the Age Concern Institute of Gerontology at King's College London, reminded the meeting that between 1994 and 2025 there will be an increase of one million people over 80 in the UK. They, including the half million who suffer from dementia, often need adaptations to their accommodation (installing a downstairs toilet, for example) to allow them to stay in it rather than moving. We need more research on the sort of housing they want and the role technology should play in it.
There may be ethical issues associated with technologically sophisticated devices for demented people: whether curtains which open and close when a beam is broken, for example, or lights which dim automatically may help or further disturb a troubled state of mind. Other groups who have special needs, as yet largely unresearched, are older women and black and minority groups. We do not yet know the implications for housing of the widening gap between rich and poor, and we need more research into that as well as into the cost of keeping people in their own homes, the high proportion of owner-occupiers, the balance between mainstream and specialised housing, the links between housing and health and the design of housing for people needing various levels of support.
Quality of life
Old people's environment is one of the factors which may be thought to influence their quality of life. However, Professor Ciaran O'Boyle, of the Royal College of Surgeons Medical School in Dublin, cautioned against any such evaluations. He reviewed various definitions of the quality of life before concluding that it is a uniquely individual phenomenon, so instead of trying to score people's quality of life against agreed criteria, researchers should find out how individuals rate their own. A person's quality of life, then, is exactly what he or she says it is.
To determine this, people are asked what five areas of life are most important to them (for example finance, work, social life, health, religion) and then to rate how they are experiencing each area (from worst possible to best possible). They then rate the relative importance of each area, so that an overall quality of life can be calculated.
Using this kind of measure, older people have been shown to have significantly higher quality of life scores than healthy young people. It seems that people adapt to their circumstances, and it cannot be assumed that somebody's quality of life is bad because they are suffering from disease. Because quality of life issues figure prominently in debates about advance directives, assisted suicide and euthanasia, there have been suggestions that someone other than the person requesting any of these should judge that person's quality of life. Studies in which people married to each other for 40 years were asked to rate each other's quality of life showed that, although the women were quite accurate at rating their husbands' quality of life, the men were not: proof that we should not rely on proxy judgements. It is not yet clear however, how we could incorporate subjective individual judgement into policy making about resource allocation.
Resources and policy implications of ageing
It is clear that societies with ageing populations will have to think hard about how they are going to support their elderly, both with pensions and health care.
Pensions
Professor James Mirrlees, Professor of Economics at the University of Cambridge, addressed the problem of a smaller working proportion of the population sustaining the consumption of a larger proportion of retired people. In the UK, people retire on average before 60, but there is no intrinsic reason why they should. Evidence from America shows that the age at which people retire is strongly influenced by fiscal incentives to keep working, and that people choose to keep working if there are incentives to do so. There are two different sorts of state pension schemes: pay-as-you-go (PAYG), in which today's workers pay in money which is used for today's pensioners; and funded schemes, in which people save a proportion of their income which is then used for their retirement, either with or without a role for Government. These have different consequences for workers and retired if the working population is small compared with those who are retired.
If the criterion for comparing the schemes is that the working generation ought to enjoy the same standard of living as those who have retired, PAYG means that the workers will be worse off, but it is not clear which group the funded pension scheme favours. The UK PAYG system is already substantially supplemented by private pension schemes, and research shows that the country could move to an entirely funded scheme quite easily.
The fiscal implications of an ageing population were further examined by Dr Paul Johnson of the Department of Economic History at the London School of Economics. The World Bank has labelled the demographic shift a looming crisis that threatens not only the children of the elderly but also their grandchildren who will have to shoulder the increasing burden of providing for them. In itself, however, this shift may not be such a crisis after all. Although its pace is faster in newly-rich countries than in Europe, there is so far nothing to suggest that these countries will not be able to cope with it. Population ageing is positive too in that it means lower fertility, decreased infant mortality and increased lifespan, all of which we value.
The problems it brings are related to the financing of health care and pensions. What has been flagged as a crisis is, however, nothing more than the maturing of the PAYG public pension scheme in which all workers are now enrolled and therefore whose contributory base cannot be widened. The only way to honour extravagant promises made from the 1950's to the 1970's about future levels of benefits, is to impose unprecedented levels of social security taxation upon future generations. This is a problem of fiscal indiscipline rather than ageing per se. Changing to a funded pension scheme will not solve the problem, however. If current trends continue, people will not only live longer but will spend fewer years in employment; and their pension needs will be difficult to finance irrespective of the method used to raise the money. There is little sign that either people or governments are willing to face up to the increased contributions that these trends point to if pensions are to be maintained at a reasonable level.
Role of health services
Sir John Grimley Evans of the Department of Clinical Geratology at the University of Oxford set out a research agenda for health services to cope with the increasing numbers of old people. We need first to agree on the outcomes we want from our health services. Old people may not necessarily want what younger people presume they want (for example, some old people refuse life-saving surgery because they do not want the indignity of having others see them under anaesthetic).
We need a national measure of healthy active life expectancy: the number of disability-free years we can expect to live. At the moment, the extra six years women can expect are all, on average, spent in physical or mental dependency. Research from America suggests that the older people are when they become ill, the shorter the period of dependence they can expect.
We need trials of services or international comparisons of the ways in which old people are treated. In the UK they have been left out of treatment trials because it is assumed that they would not benefit from them; but research has shown that whereas clot-busting treatment for heart attacks saves 25 lives for every 1000 lives under 60, it saves 80 for every 1000 lives over 70.
We need to do more research on how the intrinsic, genetic factors in ageing interact with extrinsic factors in environment and lifestyle. We also need to know how we can more effectively translate knowledge about healthy lifestyles into action. Health education improves knowledge but does little to change behaviour: doctors need to ask advice from social scientists about creating opportunities and incentives to change to healthier lifestyles. Finally, we must integrate medical and health services as a social activity within society as a whole, and not expect medicine to put right the diseases created by poor education or poverty. The Carnegie Inquiry into the Third Age (Final Report, "Life, Work and Livelihood in the Third Age", published by the Carnegie UK Trust, Dunfermline, 1993) provides a good pointer to all aspects of society which need to adapt to the new demographic structure.
The new future
The meeting ended on an upbeat note. Professor Robert Fogel, Director of the Center for Population Economics at the University of Chicago, was optimistic about the sort of social structure that an ageing population would bring. He described the driving force behind the increasing quality of life, rising standard of living and improved health care in OECD countries as the techno-physio revolution, which began 300 years ago, accelerated during the present century and is still going on. Over the next three or four decades, the working week will probably be reduced to between 28 and 32 hours, the average period of work over the life cycle to between 30 and 35 years, and the average period of retirement increased to between 30 and 35 years. Increasing spending on health care and pensions is an appropriate reaction to this process and should be welcomed rather than deplored.
The resources available now and in the future can provide increasingly long and healthy lives of luxury for all; but methods of financing health care and retirement need to be modernised. In future, luxury will be defined increasingly in terms of spiritual (that is, not exclusively religious but certainly non-material) rather than material resources, and the touchstone of well-being for young and old alike will be the quality of their health and their opportunity for self-realisation.
Wendy Barnaby
ABSW
September 1997
Contacts
Dr Robin Holliday, F.R.S.
CSIRO Division of Biomolecular Engineering
Tel: 00 612 9490 5139 Fax: 00 612 9490 5010
Professor Tom Kirkwood
Biological Gerontology Group, University of Manchester
Tel: 0161 275 5655 Fax: 0161 275 5654
Professor George Martin
Department of Pathology, University of Washington
Tel: 00 1 206 543 5088 Fax: 00 1 206 685 8356
Professor Brian Anderton
Department of Neuroscience, Institute of Psychiatry
Tel: 0171 919 3259 Fax: 0171 708 0017
Professor James Vaupel
Director - Max Planck Institute for Demography, Rostock
Tel: 00 45 6532 2227 Fax: 00 45 6532 2247
Mr Peter Laslett, F.B.A.
Cambridge Group for the History of Population and Social Structure
Tel: 01223 338455 Fax: 01223 338564
Professor Ken Wachter
Department of Demography, University of California at Berkeley
Tel: 00 1 510 642 9800 Fax: 00 1 510 643 8558
Dr H.P.A. van de Water
Division of Public Health and Prevention, TNO Prevention and Health, Leiden
Tel: 00 31 71 518 1778 Fax: 00 31 71 518 1920
Professor Kay-Tee Khaw
Department of Gerontology, Addenbrooke's Hospital
Tel: 01223 217292 Fax: 01223 336928
Professor Archie Young
Department of Geriatric Medicine, Royal Free Hospital
Tel: 0171 794 0500 Fax: 0171 830 2202
Professor Deborah Burke
Department of Psychology, Pomona College, California
Tel: 00 1 909 621 8000 Fax: 00 1 909 621 8623
Lord Young of Dartington, Hon. F.B.A.
Director - Institute for Community Studies
Tel: 0181 980 6263 Fax: 0181 981 6719
Professor Anthea Tinker
Director - Age Concern Institute of Gerontology, King's College London
Tel: 0171 872 3035 Fax: 0171 872 3235
Professor Ciaran O'Boyle
Royal College of Surgeons Medical School, Dublin
Tel: 00 353 1402 2428 Fax: 00 353 1402 2329
Professor James Mirrlees, F.B.A.
Professor of Economics, University of Cambridge
Tel: 01223 339516 Fax: 01223 335475
Dr Paul Johnson
Department of Economic History, London School of Economics
Tel: 0171 955 7061 Fax: 0171 955 7730
Sir John Grimley Evans
Department of Clinical Geratology, University of Oxford
Tel: 01865 224975 Fax: 01865 224815
Professor Robert Fogel, F.B.A.
Director - Center for Population Economics, University of Chicago
Tel: 00 1 773 702 7709 Fax: 00 1 773 702 8490
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