WASHINGTON — In the long-running nature-versus-nurture debate, genes and chromosomes have been seen as ammunition for the nature camp: unchanging templates that determine whether we have red hair or can hit a jump shot. But over the past few years, research has begun chipping away at the idea that biology is an immutable determiner of destiny. Studies have found that environmental factors like diet, smoking and even bullying can affect our DNA.
One of the latest additions to this research is a study that points to the possibility that a difficult childhood — one marked by poverty, instability and stress — can effectively “age” the chromosomes of children as young as 9 years old, potentially making them more prone to bad health down the road.
Researchers, including senior author Daniel Notterman of Penn State University, looked at a group of 40 9-year-old African-American boys: half raised in privileged homes and half raised in disadvantaged environments. They found that the boys who grew up in more underprivileged settings had shortened telomeres, the DNA sequences that sit at the ends of chromosomes and protect them from damage. Researchers do not yet fully understand the relationship between shorter telomeres and bad health, but worn-down or frayed telomeres have been associated with aging and degenerative diseases, as well as cancer.
The implications of these findings are distressing not only in the context of U.S. inequality, but also in the context of impoverished or war-torn countries. Although a study of 40 American boys does not necessarily indicate that, say, frazzled chromosomes run rampant in countries like Somalia and Afghanistan, Notterman says it raises the possibility: “There are whole populations of people who will have adverse physical and health and well-being outcomes based on the effect of stress upon their physiological functioning.” He adds that his research points to the need for early interventions to protect children’s health.
The study, in other words, reinforces what organizations like UNICEF and Save the Children have been arguing for years: Lifting children out of poverty and protecting them from war cannot happen soon enough.