Men who are unemployed for more than two years show signs of faster ageing in their DNA, a new study has found.
Researchers at Imperial College London and the University of Oulu, Finland studied DNA samples from 5,620 men and women born in Finland in 1966.
They measured structures called telomeres, which lie at the ends of chromosomes and protect the genetic code from being degraded. Telomeres become shorter over a person's lifetime, and their length is considered a marker for biological ageing. Short telomeres are linked to higher risk of age-related diseases such as type 2 diabetes and heart disease.
The researchers looked at telomere length in blood cells from samples collected in 1997, when the participants were all 31 years old. The study, funded by the Wellcome Trust, found that men who had been unemployed for more than two of the preceding three years were more than twice as likely to have short telomeres compared to men who were continuously employed,.
The analysis accounted for other social, biological and behavioural factors that could have affected the result, helping to rule out the possibility that short telomeres were linked to medical conditions that prevented participants from working.
This trend was not seen in women, which may be because fewer women than men in the study were unemployed for long periods in their 30s. Whether long-term unemployment is more harmful for men than women later in life needs to be addressed in future studies.
The Imperial team included Dr Jessica Buxton and Professors Marjo-Riitta Jarvelin and Alexandra Blakemore.
Dr Buxton, from the Department of Medicine at Imperial College London, said: "Shorter telomeres are linked to higher risk of various age-related diseases and earlier death. 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".
Dr Leena Ala-Mursula, from the University of Oulu, said: "There has been lots of research linking long-term unemployment with ill health. 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."
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Notes to editors
1. Leena Ala-Mursula et al. 'Long-term unemployment is associated with short telomeres in 31-year-old men: an observational study in the Northern Finland Birth Cohort 1966.' PLOS ONE, 20 November 2013.
After embargo link: http://dx.plos.org/10.1371/journal.pone.0080094
2. About Imperial College London
Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 14,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.
Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve global health, tackle climate change, develop sustainable sources of energy and address security challenges.
In 2007, Imperial College London and Imperial College Healthcare NHS Trust formed the UK's first Academic Health Science Centre. This unique partnership aims to improve the quality of life of patients and populations by taking new discoveries and translating them into new therapies as quickly as possible.
3. About Northern Finland Birth Cohort 1966
The Northern Finland Birth Cohort 1966 study sets out to explore the genetic and environmental factors affecting long-term morbidity, intermediate disease markers and social wellbeing throughout the life-course. The unique data have been gathered since the foetal period in 1965. Hosted by the Institute of Health Sciences at the University of Oulu, Finland, the NFBC1966 study actively collaborates with research teams at Imperial College London. The Northern Finland Birth Cohort (NFBC1966) study received financial support from the Academy of Finland (project grants 104781, 120315, 129269, 1114194 and SALVE), University Hospital Oulu, Biocenter, University of Oulu, Finland (75617), the European Commission (EURO-BLCS, Framework 5 award QLG1-CT-2000-01643), and the Medical Research Council, UK (G0500539, G0600705, PrevMetSyn/SALVE). The DNA extractions, sample quality controls, biobank up-keeping and aliquotting were performed in the National Public Health Institute, Biomedicum Helsinki, Finland and supported financially by the Academy of Finland and Biocentrum Helsinki.