The Scientific Aspects of Ageing

The Scientific Aspects of Ageing

The Royal Society of Edinburgh (RSE) is pleased to respond to the House of Lords Science and Technology Sub-Committee Inquiry into the Scientific Aspects of Ageing. This response has been compiled by the General Secretary, Professor Andrew Miller and the Research Officer, Dr Marc Rands, with the assistance of a number of Fellows with considerable experience in this area.

Biology, genetics and lifestyle all influence how a person ages, and a greater understanding of how these factors influence "healthy" ageing will allow us to begin to elucidate the aetiology of age-related disease. In this context, the Royal Society of Edinburgh is undertaking a range of activities in this area with the support of the Lloyds TSB Foundation for Scotland, and is supporting research and scholarly activities aimed at improving the quality of life of Scotland’s ageing population.

The specific areas of the call for evidence are now addressed below:

The Biological Processes of Ageing

What are promising avenues for research? How will such research benefit older people and delay the onset of long-term illnesses and disabilities?

Ageing Brain

The ageing brain is one of the most important avenues for research on the biological processes of ageing. Cognitive functions, like aspects of memory, reasoning, speed of mental processing, and executive functioning, tend to decline as people grow older. This applies even in people who do not have dementia or Mild Cognitive Impairment. Cognitive decline, including pathological and non-pathological aspects, is a major cause of lost independence for older people, a major factor in lowering quality of life, and is a huge financial burden on families and society.

NHS Scotland’s Source Document "Risk Factors for Dementia and Cognitive Decline," issued in October 2003, and the USA’s National Research Council report in 2000 on "The Aging Mind: Opportunities in Cognitive Research" identified neural health, cognition in context, and structure of the ageing mind as key areas for research on the ageing brain.

In particular, not enough is known about the phenotype of cognitive ageing. For example, which mental processes deteriorate, when they do so, the brain basis of this change, and how the deterioration of mental processes correlate. Too little is also known about why some people’s functions deteriorate while others remain intact or even improve. Too little is known about the biological basis for the correlation between age-related change in cognition with age-related changes in functions such as the senses, grip strength, and lung function. Similarly, more needs to be known about whether cognitive decline is related to illnesses, either overt or subclinical pathology.

In addressing these issues, there are now new ways to image the brain’s white matter, which allows hypotheses about cortical disconnection to be studied in relation to age-related cognitive change and to follow up ideas about oxidative damage as a basis for cognitive ageing. The genetic basis for cognitive ageing is also now possible with large-scale, fast-throughput genotyping, and telomere length can be studied as a correlate of cognitive ageing. There are, however, too few studies of endophenotypes of cognitive ageing, using experimental and psychophysical measures that can translate cognition into basic processes.

Gene-exercise interactions on bone health

Another important aspect that has changed over the last few decades is our increasingly sedentary lifestyle and the impact that this has had on "healthy" ageing. This is of particular importance in the musculoskeletal system. As we age it is inevitable that we lose bone strength and the outward manifestation of this age-related decline is frailty, falls and fractures as a result of osteoporosis. It is estimated that 1 in 3 women and 1 in 12 men over the age of 50 will suffer an osteoporotic fracture with the resulting cost to the NHS and government of 1.7 billion per annum.

Physical activity has been shown to be an essential factor in bone health and the skeletal benefits of exercise can be demonstrated throughout our life cycle. Exercise can positively affect peak bone mass in children and adolescents, has been shown to help maintain or even modestly increase bone density in adulthood and can assist in minimizing age related bone loss in older adults. While the skeleton responds positively to mechanical loading by increasing bone mass and strength (functional adaptation) this response declines with age in both sexes. Not only is the loss of functional adaptation of bone a major aspect of the ageing process it is also highly variable between individuals suggesting a genetic contribution to the response. In fact understanding the interaction and the influence of environmental factors such as exercise on gene expression and function is one of the key areas that should be highlighted in our research effort. Understanding the cellular, biochemical and molecular basis of gene-exercise interactions is, therefore, essential to improving bone health and performance through exercise.

Despite the general belief in the importance of exercise to our health, the molecular and cellular structures/systems that contribute to the mechanostat in cells, particularly in the musculoskeletal system, remain unclear. This information would contribute to the design of pharmacological interventions to load related diseases or preventative strategies in health programmes and to our understanding of the mechanisms behind alteration of the sensitivity of this system during ageing and disease such as osteoporosis, osteoarthritis and Pagets disease. An understanding of the basic mechanism of the response to mechanical stimulation is also fundamental for repair and regenerative medicine. One area of research which has been highlighted in the Foresight Health Care 2020 report is tissue engineering with the long term aim to treat age-related degenerative disease disorders. The development of engineered tissues ex vivo for transplantation will fail if we do not understand the components of the ageing process in vivo that lead to an impairment of the mechanosensor mechanism and hence disease in the elderly. We should, therefore, aim to increase the understanding of mechanically responsive cells using techniques at the interface between biology and engineering.

Large scale population based studies have provided clues to the likely impact of genetic status on the development of a number of age related disease of the musculoskeletal system. However they have largely failed to develop a clear idea of the genetic lesions involved at the level required to develop genetic screens to identify members of the population at risk. There is also need to focus on a functional genetics approach in order to identify genes with possible impact on the musculoskeletal health based on their known importance in the function of these tissues. Only with this information can the most useful data from the large population genetic studies be extracted.

The application of research in technology and design to improve the quality of life of older people

Existing technologies which could be used to a greater extent to benefit older people

There are a number of existing technologies that could be used to a greater extent to benefit older people. For example, research could be undertaken into a "home hospital" for the elderly. An elderly person can find it difficult to go to the doctor or hospital but communication technology is available whereby he/she can do much by him/herself without directly taking up doctors’ time or hospital facilities. For example, computer technology developed for the home office could be adapted for home medical care and with good communication channels a patient can use a digital thermometer which a doctor can "read", or carry out blood pressure measurements, and communicate with the doctor.

However, although maintenance of the elderly in their own homes is often the best option, the likely rise of IT support mechanisms and surveillance of old people in their homes (such as that that developed by SECOM in Japan) may lead to isolation and increasing mental problems. More specialists, psychologists and psychotherapists, community care workers and "friends" will, be required to maintain mental health and physical independence of elderly people.

The development of new technologies

As noted above, the loss of bone mass (10% of loss of strength for each decade of years) with age is a major concern and leads to osteoporosis and fractures. New technologies are therefore needed for stimulating bone growth. New lightweight bio-compatible materials and techniques also need to be developed for improved implant/bone fittings that can enable secure extended life for these implants and reduce the need for revision surgery. In particular, new coating technology for implants is required, providing greater wear resistance, as well as biocompatibility.

How effectively is research co-ordinated in the public, private and charitable sectors (including internationally)?

There has been a UK response to the challenge of the scientific aspects of ageing. Most of the research councils have had ageing-related initiatives, and the National Collaboration on Ageing Research has begun to bring some of these together. Ageing-related charities, such as Research into Ageing, National Osteoporosis Society and Arthritis Research Council, have also been supportive of research into the biological processes of ageing.

Cognitive ageing will, however, require longer-term support for cohorts of subjects, organising researchers in large-enough multidisciplinary teams, and a more co-ordinated approach to funding and a body such as the USA’s National Institute on Ageing would help matters considerably.

Have the correct priorities been identified? Are there any gaps in research?

In addition to the areas identified above, current research into Alzheimers, Parkinsonism, and like afflictions will be important, as will continuing research to find ways of preventing or curing the major degenerative diseases such as cancer and diabetes. Research over the past 50 years has also produced useful guidance in respect of diet and exercise and the avoidance of risk-producing habits such as smoking and some features of life-style. Some aspects of these, still need further well-planned research to confirm or modify current beliefs and there will be a need to examine the psychological barriers that prevent people following oft-repeated simple advice on healthy living.

Is there sufficient research capability in the UK?

There are current difficulties in maintaining sufficiently large cohorts of people over time to explore cognitive ageing. There are some exceptions, such as the MRC’s 1946 British Birth Cohort, which effectively has long-term funding, but some of the world-class cohorts that this country possesses are run on short-term grant support. In addition, there would be benefit in researchers on brain ageing being brought together in larger groups, a rare example of which has occurred in Newcastle.

Is the research being used to inform policy?

An ageing population presents a massive health and financial burden, and research findings are being publicised and influencing policy, especially given the economic and social consequences for communities.

Additional information

In responding to this inquiry the RSE would like to draw attention to the following Royal Society of Edinburgh responses which are of relevance to this subject: The Ageing Population (December 1999); EQUAL (Extend Quality Life) (January 2000) and Healthcare in 2020 (September 2000).

October 2004

Copies of the above publications and further copies of this response are available from the Policy Officer, Dr Marc Rands

 

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