People who leave education with fewer academic qualifications may grow old faster, according to a DNA study that compared groups of people who spent different lengths of time in education and found the ones who spent the least time had shorter telomeres or "caps" on the ends of their DNA, a sign of premature aging in cells.
Co-funded by the British Heart Foundation (BHF) and the Medical Research Council (MRC), and led by University College London (UCL), the study used 450 volunteers from the ongoing "Whitehall II" study, which started in 1985 to investigate links between social class and health.
BHF's Associate Medical Director, Professor Jeremy Pearson, said the study reinforces the need to tackle social inequalities to combat ill health:
"It's not acceptable that where you live or how much you earn -- or lesser academic attainment -- should put you at greater risk of ill health," he said in a statement.
Andrew Steptoe, BHF Professor of Psychology at UCL, and colleagues, wrote about their findings in a paper published recently in the journal Brain, Behavior, and Immunity.
They were concerned that while there is evidence that low socioeconomic status is linked to faster biological aging, attempts to tie it telomere length have yielded inconsistent results.
Telomeres are short repetitive sequences of DNA that "cap" the ends of chromosomes and stop them degrading and fusing with their neighbours: imagine the tips on the ends of shoelaces that stop them fraying. Telomeres get consumed in cell division, and are replenished by an enzyme called telomerase, but there is a limit to how many times this can happen, and they gradually get shorter, limiting the number of times cells can divide, and in turn, lifespan.
The researchers set out to test the hypothesis that "shorter telomere length and telomerase activity would be related more robustly to education, an early life indicator of socioeconomic position, than to current indicators of socioeconomic circumstances".
For the study, they split the 450 volunteers, healthy men and women aged between 53 and 76 years, into four groups according to how long they had spent in education.
They also measured their current socioeconomic status in terms of household income and grade of employment.
From blood samples, they were able to assess telomere length in 448 of the participants and telomerase activity in 416.
After adjusting for possible confounding factors, such as age, gender, various health indicators such as smoking and cholesterol, and lifestyle indicators such as exercise, they found that lower educational attainment was linked to shorter telomere length, while household income was not, and neither was employment grade.
In fact, the link between "telomere length and education remained significant after adjusting for current socioeconomic circumstances," they wrote.
They also found that in men, the highest telomerase activity (the enzyme that repairs the telomeres) was in the lowest education group.
The researchers concluded that low socioeconomic status defined in terms of education but not current socioeconomic circumstances is linked to shorter telomeres.
This supports the idea that faster aging is not just a result of current economic circumstances or social status in a person's life, but of long-term effects that start early in life, such as education.
The researchers also suggest that people with higher levels of education are probably better equipped with life skills like problem-solving that help them deal with the stresses of life, and this reduces the biological stress on their bodies, the so-called “allostatic load”.
"Educational attainment but not measures of current socioeconomic circumstances are associated with leukocyte telomere length in healthy older men and women."
Andrew Steptoe, Mark Hamer, Lee Butcher, Jue Lin, Lena Brydon, Mika Kivimäki, Michael Marmot, Elizabeth Blackburn, Jorge D. Erusalimsky.
Brain, Behavior, and Immunity, In Press, Uncorrected Proof, Available online 23 April 2011.
DOI:10.1016/j.bbi.2011.04.010
Additional source: BHF.
Written by: Catharine Paddock, PhD
Copyright: Medical News Today