Scientists explain why old people become weak
A laboratory researcher using a light microscope to examine stem cells in a culture jar.
What you need to know:
- A study conducted by scientists from the Wellcome Trust Sanger Institute and published in the scientific journal Nature illustrates that once someone reaches the age of 70, they are at risk of certain diseases because of changes that occur in the body.
- The scientists have linked this to the genetic changes that occur in people’s blood stem cells.
If you have been wondering why the older one gets, the weaker they become; scientists have tried to unearth this mystery. A study conducted by scientists from the Wellcome Trust Sanger Institute and published in the scientific journal Nature illustrates that once someone reaches the age of 70, they are at risk of certain diseases because of changes that occur in the body.
The scientists have linked this to the genetic changes that occur in people’s blood stem cells. “Age-related phenotypes (observable characteristics) in blood include anaemia, loss of regenerative capacity, remodelling of the bone marrow microenvironment and increased risk of blood cancer,” said the study.
The researchers analysed how people’s blood cells in the bone marrow are produced. They also looked at people’s lifespan and how strong they stay, deducing that they become weaker once they get to the age of 70.
In a press statement by the Wellcome Trust Sanger Institute, Dr Emily Mitchell, one of the researchers who took part in the study, explains why the frail nature of old people is linked to the blood stem cells.
“Our findings show that the diversity of blood stem cells is lost in older age due to positive selection of faster growing clones with driver mutations. These clones ‘out-compete’ the slower growing ones. In many cases this increased fitness at the stem cell level likely comes at a cost — their ability to produce functional mature blood cells is impaired, so explaining the observed age-related loss of function in the blood system,” she says.
She explains that there are some driving factors that can speed up the ageing process.
“Factors such as chronic inflammation, smoking, infection and chemotherapy cause earlier growth of clones with cancer-driving mutations. We predict that these factors also bring forward the decline in blood stem cell diversity associated with ageing. It is possible that there are factors that might slow this process down, too. We now have the exciting task of figuring out how these newly discovered mutations affect blood function in the elderly, so we can learn how to minimise disease risk and promote healthy ageing,” she says.
