Of Nature, Nurture, Deprivation … and Telomeres
By Brian W. Donnelly, M.D., Pediatric Alliance — North Hills Division
A recent study in the Proceedings of the National Academy of Sciences (PNAS) reveals how chronic stress can exert measurable effects on young boys. The research looked at the relative length of telomeres in 9-year-old African-American children participating in the Fragile Families and Child Wellbeing Study.
Telomeres are regions of repetitive nucleotide sequences at each end of the chromatids. They are thought to protect the ends of the chromosomes from deterioration. Smoking, depression, caregiver stress and obesity have been associated with shortened telomere length in adults.
A useful analogy is shock absorbers. Driving without shock absorbers will give one a much rougher ride, and may lead to other incidental injuries. Longer telomeres, and new shock absorbers, afford us more protection and make the ride smoother.
In the study, low income, low maternal education, unstable family structure, and harsh parenting were associated with short telomere length in the young boys. The more stressors these boys experienced, the shorter their telomeres (and the bumpier their rides may be to good health in life).
The other interesting finding here was that genetic differences in the way serotonin and dopamine (important neurotransmitters) are processed impact the process of telomere shortening. Boys with the highest scores in dopamine and serotonin genetic sensitivity had shorter telomere lengths in disadvantaged environments and longer lengths in advantaged settings.
Also, testing of the chromosomes in this research project was done using saliva, not blood. This obviously is much less invasive and much more popular among children, whatever their ethnic background or their social standing.
One of my favorite Christmas carols is “All I Want for Christmas is My 2 Front Teeth.” When, that is, it is sung by a partially edentulous 7-year-old. So, do we need to teach our disadvantaged 9-year-olds the same tune, but change the lyrics to “All I Want This Season is Longer Telomeres?” Or maybe we need to devise ways to increase the amounts of telomerase reverse transcriptase (the enzyme that increases telomere length) in these kids?
Whatever the implications, this study is important in offering us a potential way to quantify chronic stress in children.
More on this study in Nature here.