WHY ARE WE LIVING LONGER?
MJA members were treated to a fascinating review of the research into human longevity and ageing in the elegant Georgian surroundings of the University Women’s Club, Audley Square London, in June. An important clinical take-home message emerged: a radical change in how hospitals and GPs treat the over-85s is required, combined with greater emphasis on low-tech interventions like diet and exercise. Helen Saul reports.
Life expectancy worldwide has increased linearly for the past 200 years, said foremost UK authority on ageing and longevity, Tom Kirkwood (Institute for Ageing and Health, Newcastle University). It’s an ‘absolutely astonishing’ pattern, he said – rare in that plotted data conforms so closely to a straight line – and it has confounded the best demographic forecasters in the world, who have repeatedly predicted a slowing of the increase.
Up to the middle of the 20th century, the increase was explained by fewer deaths from accidents and infectious diseases in the early and middle years of life. But since the 1980s, a completely new driver of increasing life expectancy has emerged, said Kirkwood. ‘People are reaching old age in better and better condition. The major contributor to ongoing increase in life expectancy is the decline in later-life mortality. Death rates among over-80s and above in the UK are now less than half what they were in the 1950s. This is absolutely enormous and perhaps explains why governments and other agencies have been so slow to wake up to what is happening to longevity around the world.’
At a biological level, ageing is caused by random molecular damage, leading to an accumulation of defects in cells and tissues over time. Over decades these defects lead to age-related frailty, disability and disease, he said. Living in an adverse environment, with poor nutrition, lack of exercise, and so on, can accelerate the accumulation of damage. By contrast, a healthy lifestyle empowers the body’s intrinsic mechanisms for maintenance and repair, and can postpone it. The result is ‘a very steep socio-economic gradient in terms of health and life expectancy’. This contributes to major social issues such as how long people should work and when draw pensions. ‘Changes to pension ages are not such a challenge for those with good working lives and who come from privileged socio-economic backgrounds. But there are many people for whom the new expected age of retirement is beyond the age they can expect to be in good health.’
Research into the genetics of ageing has proved ‘frustrating and difficult’. But
Kirkwood was one of the authors on a landmark paper in 1994 which identified the first gene linked with ageing, ApoE, associated with Alzheimer’s disease. Nearly 20 years on, he has just analysed data on a large European study of families that have significant numbers of long-lived individuals. The one factor that comes out strongly is the absence of the ApoE gene, bringing research ‘in a full circle’.
Kirkwood believes genetic research will progress. But the second speaker, Richard Faragher (professor of biogerontology, University of Brighton), while broadly agreeing with the biological model of ageing presented by Kirkwood, gave a slightly more optimistic picture of genetics research. He suggested that instead of there being distinct causal mechanisms for age-related diseases such as cardiovascular disease or cancer, there might actually be a very few mechanisms for ageing, but that their expression through life might drive many of the age-related pathologies. If these pathways could be blocked, he said, ‘we would go from a state of ageing badly to a state of ageing well’.
Unpublished work from his own laboratory suggests that when senescence cells were deleted, there was a significant delay in ageing-associated disorders – in mice. ‘We now have to unpick how relevant this is. For those of us who have worked in the area, it’s pretty heartening. I like to think that the mechanisms that control the ageing process are clearer than when I started back in the 1980s. If we can really drive down on these, we could compress morbidity, extend lifespan, save money and increase human happiness.’
One barrier to progress was a short-sighted lack of funding for research in ageing, said Faragher. And yet, ‘If something came out of UK laboratories studying ageing to reduce the burden on the NHS, it wouldn’t just pay for all ageing research, it would pay for all universities,’ he said.
Kirkwood added that it had been unbelievably hard to get funding for the Newcastle 85+ study. This MRC-funded study, started in 2006, includes everyone born in Newcastle in 1921, and looked for the presence or absence of 18 different diseases. It found that, despite the fact that 78 per cent of the group self-rated their health as good, very good, or excellent, most had between three and six medical conditions. Before the study, the paucity of information on the health status of 85-year-olds was not recognised as a problem. Now that data was coming in, it was having an impact, he said, and he would like to set up a similar study on a cohort born a decade later. ‘We won’t fill the information vacuum unless we start designing trials in the right way now. This underpins all our planning for the future in terms of health service provision.’
As a result of the 85+ study Kirkwood described a new clinic now being trialled in Newcastle. There are 10 CRESTA (clinic for research and service through themed assessments – yes, it’s not perfect, but they worked on the acronym for ages) clinics per week, each dealing with different complex co-morbid conditions. ‘Instead of the patient bouncing around to outpatient departments, the specialists come together in a single clinic and examine the patient from the different perspective of their specialty. They then confer at the end of the clinic and a treatment course is designed that takes account of all the things they have been able to look at. I am firmly convinced that though this has only been running for two months, this is the future of NHS treatment for this age group, though it has to be proven.’ Organisational changes could also make a huge difference to elderly patients in primary care. The RCGP has recognised that older patients need consultations of 15 minutes rather than the standard seven.
‘It is unreasonable to ask elderly patients with co-morbidity to bring one problem at a time, as some GP practices do. The current system means that many elderly ‘have a shopping list of prescriptions and nothing ever gets taken off. They just get a new one added and it needs someone to review the list,’ Kirkwood said. Hospital appointments similarly are designed around patients with single conditions. Patients see one specialist, dealing with one facet of their health at a time. And receive a prescription accordingly.
Asked what we can all do to increase our chances of a healthy old age, the answer sounded familiar. ‘There is nothing high-tech science can do for your ageing at the moment, and a great deal that low-tech science and interventions like nutrition and exercise can do,’ Kirkwood said.