That aging is evident in their DNA, the British researchers reported. More specifically, it is found in the length of the gene tips or caps, referred to as "telomeres." The shortening of telomeres has long been seen as an indicator of aging.
"Shorter telomeres are linked to a higher risk of age-related conditions, such as heart disease and type 2 diabetes," said study author Jessica Buxton, a research associate in the department of medicine at Imperial College London. "It seems that long-term unemployment is the latest example of a stressful life experience that may trigger permanent changes to the cell's DNA.
Too much work can also be harmful
"It's important to note that other studies have shown too much work can be as harmful as too little," she said. "Work-related exhaustion and the holding of multiple jobs have also been linked to shorter telomeres."
The report was published in the online journal PLoS One.
Constant stress over a long time changes the hormones in one's body, said Curtis Reisinger, a clinical psychologist at Zucker Hillside Hospital in Glen Oaks, N.Y. This may be what is causing these changes in telomere length.
"You see the same thing with depression and high stress levels," he said. "The consequence is that you wind up looking and feeling older."
Reisinger said seeing a mental-health professional can help relieve stress. But having a positive attitude also is important.
"This is not the end of the world," he said. "You have to stay focused and have faith that if you keep at it and have a positive outlook, chances are you will be more likely to get a job than if you're down in the dumps and pessimistic."
How the study was done
For the study, Buxton and her colleagues examined DNA from more than 5 600 men and women born in Finland in 1966.
Specifically, they looked at telomere length in DNA samples collected in 1997, when the participants were 31 years old.
The researchers found that men who were unemployed for more than two out of the previous three years were more than twice as likely to have short telomeres compared with men who were employed.
To be sure their findings resulted from unemployment alone, the researchers accounted for other social, biological and behavioural factors that could cause shortened telomeres.
"It's interesting that unemployment itself appears to have a negative effect on health, even after accounting for the potential effects of smoking, physical-activity levels, weight, illness, education and marital status," Buxton said.
Buxton's team found this effect among men and not women, which might be because there were fewer unemployed women in the study, she said.
Although the study found an association between unemployment and faster ageing, it did not prove a cause-and-effect link.
