Traumatic experiences as a child can shorten your life: Stressful events speed up the body's ageing process

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People often talk about how they feel stressful experiences have taken years off their life - and now this has proven to be true.

Being bullied or abused in childhood can shorten a person's lifespan significantly, according to a new study.

Trauma shortens the protective structures on the ends of the strands of their DNA, and this can shorten their life expectancy.

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Being bullied or abused in childhood can take years off people's lives, according to a new study. Trauma shortens the protective structures on the ends of the strands of their DNA, and this can shorten their life expectancy (stock image)

Difficult upbringings - including poverty and social or traumatic problems - leave a lasting imprint on health, according to the new research, led by scientists at the University of British Columbia.

It shortens telomeres - the protective structures on the ends of the strands of DNA called chromosome - which have been likened to shoelace caps.

Previous research has found their length is a sign of cellular ageing and can reliably predict life expectancy in humans.

The study looked at the telomeres in saliva glands of 4,598 over 50s.

Participants were more likely to have short telomeres if they had been through stressful events in their life - particularly childhood. 

The risk increased by eleven per cent for each additional problem experienced as a youngster.

These problems included things like a father losing his job or parents suffering from substance abuse. 

Compared with financial hardship, social or traumatic stress during this time was more likely to shorten telomeres.

Individual stressful events did not seem to be related to the phenomenon, reports Proceedings of the National Academy of Sciences.

'The gradual ageing of the immune system is partly marked by shortened telomeres - the DNA-protein caps at the ends of chromosomes that protect genes from degradation,' said Dr Eli Puterman, lead author from British Columbia University in Vancouver. 

Telomeres are the protective caps on the ends of the strands of DNA called chromosomes, which house our genomes. In this artist's impression, they are visible as highlights at the tips of the chromosomes

Other factors considered were if the person had experienced physical abuse before the age of 18, had to repeat a year of school or had got into trouble with police.

The first three childhood adversity items were considered financial in nature whereas the final four were social or traumatic.

Data were taken from the US Health and Retirement Study - a nationally representative sample of US residents.

The team used 16 years of self-reported financial, traumatic and social stresses from childhood and adulthood.

They said the study supports previous findings childhood adversity could influence cellular ageing later in life.

'Accumulated adverse experiences in childhood significantly predicted an increased likelihood of having short telomeres later in life - suggesting a potential pathway through which childhood experiences have been previously shown to predict adulthood morbidity and mortality,' Dr Puterman said.

It's one of the first studies to look at explored the relationship between telomere length and the build-up of stress throughout childhood and adulthood.   

'This study suggests that the shadow of childhood adversity may reach far into later adulthood in part through cellular ageing.'

Two years ago a study in the UK found those from more well-off backgrounds will live life to the full almost 20 years longer than poor.

Although it has long been recognised there is gap between rich and poor in terms of life expectancy the difference between the richest and poorest in 'healthy life expectancy', the length of time people can expect to lead an active life in good health, is as much as 19.3 years.

Dr Puterman said ageing cells play a crucial role in the cause of non-communicable diseases and telomere shortening is an important part of this process.

Studies have shown genetic variants linked with shorter telomeres are linked with cardiovascular, lung and Alzheimer's diseases.

'Not all children who experience adversity are at similar risk and investigating resiliency within the context of adversity is emerging as a new frontier in adversity research,' he said.