Men who remain out of work for more than two years show accelerated cellular aging in their DNA, according to a new study on unemployment.

Researchers at Imperial College London and the University of Oulu, Finland analyzed the blood samples of 5,620 men and women born in Finland in 1966. Specifically, the team looked at the samples taken in 1997, when they recorded the length of each subject’s telomeres — the cap-like structures on the tips of chromosomes that protect the cell’s DNA. Men who had been unemployed for more than two of the preceding three years were twice as likely to have shorter telomeres compared to men who had been continuously employed.

Telomere shortening is only one component of aging, according to current scientific theories. Other components include oxidative stress, glycation (glucose sugar binds to and inhibits DNA, proteins, and lipids), and chronological age, as risk factors tend to increase over time. The combination of these four all comprise, in some capacity, the phenomenon of cellular aging.

Effectively, these four processes are what prevent humans from being immortal. The body undergoes stressful processes that wear it down, and even though cells divide to alleviate the burden, they only do so 50 to 70 times in the average person’s life. When cells divide, the telomeres must lop off a portion of the existing DNA, in order to compensate for what’s lost in duplication. These newly shortened telomeres pose certain health risks, mainly because the frayed chromosome ends that were once protected now face the danger of fusing together, potentially degrading the cell’s blueprint.

Telomere shortening has been shown in prior studies to associate strongly with aging-related diseases, such as heart disease, diabetes, obesity, and cancer. It’s also been linked with depression.

The present study now suggests that long-term unemployment falls into that mix. Apparently, the stress caused by joblessness, emotionally and mentally, has similar effects on men’s telomeres as chronological aging. Interestingly, the trend wasn’t observed in women; researchers speculate this may be because fewer women than men in the study were unemployed for long periods in their 30s.

"Shorter telomeres are linked to higher risk of various age-related diseases and earlier death,” study researcher Dr. Jessica Buxton, of the Imperial College London, said in a statement. “Stressful life experiences in childhood and adulthood have previously been linked to accelerated telomere shortening. We have now shown that long-term unemployment may cause premature ageing too."

The team’s analysis controlled for other factors, as well, such as social, biological, or behavioral components that may have affected the results. Preexisting conditions, for instance, could possibly preclude someone from working but wouldn’t necessarily reveal telomere shortening.

Why men and women differed in the length of their telomeres deserves further research, the team concluded. They also stressed that any programs that get people back to work could potentially lengthen their lives.

"There has been lots of research linking long-term unemployment with ill health,” said Dr. Leena Ala-Mursula, from the University of Oulu. “This is the first study to show this type of effect at a cellular level. These findings raise concerns about the long-term effects of joblessness in early adulthood. Keeping people in work should be an essential part of general health promotion."