Mark Downs
Chief Executive, Society of Biology

https://doi.org/10.36866/pn.98.10

The longest known human lifespan was that of Jeanne Calment who lived to well over 122 in the city of Arles, France. She survived not only time but the World Wars and pandemics that swept through Europe in her lifetime. The contenders for her title are internationally spread but predominantly female. Many suggestions are made about what longevity could be attributed to, but as yet there is nothing definitive or easily applied.

The pursuit of long life has recently made significant headway with worldwide average life-expectancy showing a marked increase from 1960 to the present. The developed world has had higher life expectancies throughout that period, but the gap is narrowing. Reductions in childhood mortality, accidental deaths and early mortality are a welcome contribution to this, giving more people the opportunity to live well into adulthood. But the increased proportion of the population that are ageing brings new challenges. Extended lifespan is not attractive without extended ‘health span’, and as we increasingly see, the combination of physical and cognitive health is essential.

So how do we achieve this without relying on pharmaceutical cocktails with all the harm-benefit dilemmas that these raise? In times of limited resources should the public purse focus on long-term understanding of the biology of ageing and the hope of insight that this might bring, or serve the care needs of an already ageing and infirm population?

Recently there has been a lot of excitement about dietary restriction and its effect on lifespan. In a recent interview in The Biologist, Dame Linda Partridge, director of UCL’s Institute of Healthy Ageing explained some of her research:

‘Dietary restriction to extend lifetime is one of the oldest models, dating back to the 1930s. It is no small effect, either. In mice you can extend lifespan by about 50%. … ‘There are people who do dietary restriction – strangely it’s almost all men – and were they to suffer from a car accident or trauma, they would probably be less able to cope with that. And, when they do get something like the flu, they have to eat up to shift it, so it is not without its downsides. …

‘The idea is that we develop a pill that has this effect without any of the downsides and without people actually having to restrict their diet in that way, which realistically is off limits to most people. … ‘We are well aware of the demographics and economics of ageing but we are not trying to make people live longer. We want people to be healthier for longer, ideally healthy right up until they die in their sleep. Lifespan has been increasing for 2.5 years per decade since the 1900s and that is set to continue. Ageing is a risk factor in many of the long-term chronic illnesses that we are seeing more of, such as Alzheimer’s and heart disease.’

A recent study by the Royal Academy of Engineering summarised the size of this challenge. Currently, 16% of the population is over the age of 65, with just 19% under the age of 16. By 2034, it is projected that 23% of the population will be over the age of 65 with 18% under the age of 16. The fastest growing age group is those over the age of 85. Currently there are 1.4 million in this bracket, but this is forecast to increase to 3.5 million by 2034.

An ageing population will lead to an increase in illnesses such as dementia and diabetes. In the UK today, 700,000 people are affected by dementia. This number is expected to double within a generation. Dementia currently costs the UK economy £20 billion per annum and a 2008 King’s Fund study projected a rise to £50 billion by 2038. There are 2.6 million people in the UK with Type 2 diabetes and this is expected to increase to 4 million by 2025. The costs of diabetes are high because of associated complications such as heart disease, stroke, kidney disease, visual impairment, nerve damage and amputations. Other major illnesses that affect older people include cancer, Parkinson’s disease and strokes.

The ageing population is going to raise many challenges over the next few decades and the UK life sciences sector will have a critical role to play in tackling many of these issues.

Our Biology: Changing the World project has recently installed 10 new blue plaques around the UK to celebrate the eminent but sometimes unsung heroes of biology; Richard Owen, founder of the NHM is remembered at his old school in Lancaster, Dolly the Sheep and the team who created her are commemorated at their lab in Edinburgh, and Steptoe, Edwards and Purdy, IVF pioneers are honoured at their old clinic in Oldham. The project also includes a free app, website and teaching resources, to celebrate great biologists of the past in order to inspire the next generation: biologyheritage.societyofbiology.org