A stressful job and lifestyle could damage a person’s short-term memory in old age, scientists have warned.
A study at the University of Iowa has found a potential link between a hormone and short-term memory loss in older people.
It revealed that having high levels in cortisol – a natural hormone in the body, which increases when a person is stressed – can lead to memory lapses as a person ages.
Short-term increases in cortisol levels are vital for survival. The hormone allows a person to cope, helping the body to respond to life’s challenges by making it more alert and allowing a person to think on their feet.
But abnormally high or prolonged spikes in cortisol, which can happen when a person is dealing with long-term stressful situations, can lead to digestion problems, anxiety, weight gain and high blood pressure, studies have shown.
Jason Radley, an assistant psychology professor at the University of Iowa, said: ‘Stress hormones are one mechanism that we believe leads to weathering of the brain.
‘Like a rock on the shoreline, after years and years it will eventually break down and disappear.’
Scientists linked the raised levels of cortisol to the gradual loss of synapses in the prefrontal cortex, the region of the brain that houses short-term memory.
Synapses are the connections that help the brain process, store and recall information.
As a person ages, repeated and long-term exposure to cortisol, can cause synapses to shrink and disappear.
While previous research has shown cortisol produces similar affects in other regions of the ageing brain, this is the first study to examine its impact on the prefrontal cortex, the university said.
Although the results are preliminary findings, scientists said they could provide the basis for research into how short-memory decline in ageing adults could be slowed or prevented.
The study, published in the Journal of Neuroscience, could also raise the possibility of finding treatments that reduce cortisol levels in susceptible individuals.
It could mean treating people who have naturally high levels of cortisol, including those who are depressed, or those who experience repeated, long-term stress due to traumatic life events, such as the death of a loved one.
The study found short-term memory lapses linked to high levels of cortisol begin to affect a person around the age of 65.
But researchers warned that it is important to remember that stress hormones are only one of a host of factors which affect mental decline and memory loss as a person ages