Clues to ageing and more from the blood
Trawling the newspapers each week for articles which tell us about dementia and issues of ageing, I am pleased and to a degree surprised, to find few which express ageist views of values. It is heartening to contrast the news of scientific and medical advances – many of which have potential to extend and improve life beyond 60 – with the sadness and frustration associated with the economic and personal tragedies arising from human greed.
This week a short report draws attention to extraordinary research coming from Cambridge University working with other centres: Research may reveal why people can suddenly become frail in their 70s | Ageing | The Guardian
Clonal dynamics of haematopoiesis across the human lifespan | Nature
There are 30 authors to this detailed and highly technical study – first author Emily Mitchell through to senior author Peter Campbell. The investigation drew material from ten people with ages ranging from the first year of life to 81. Stem cells were sourced from the umbilical cord in neonates and from bone marrow at other ages. The findings are that for the first seven decades of life red and white blood cells are produced from a wide range of stem cells- 20,000 to 200,000 – so there is a spectrum of potency which gives great resilience. From the mid-seventies onwards a few stem cells become dominant and the safety net which comes from variety is progressively lost. Cancers, blood cancers and anaemia are more likely and resistance to infection and other assaults is weakened.
This feels like an important penny-dropping understanding of how things work. It is at odds with previous beliefs that ageing and mortality are derived from the accumulation of mutations. It fits with a survival-of-the fittest model – but unfortunately the survival of a few strong cells at the expense of the full community of stem cells leads to vulnerability and the death of the whole.
A parable in stem cells. A lesson for the learning.
What has been seen here within the haematopoietic system may be what happens in other organs too – including the brain. Whether this new insight can lead to actions which are therapeutic remains to be seen – probably well beyond my life-time – but there is quiet and deep satisfaction in gaining the knowledge. We are looking beyond the top of the mountain