The stress of caring for a sick child can add 10 or more years to the biological age of a woman's cells, researchers have found.
I've been puzzling about this for a while. What adaptive advantage is there for stress to accelerate aging? It seems like evolution went to some trouble to make this happen (note to creationists -- I'm speaking metaphorically).
I can't come up with value for a human adult, but unfortunately for attempts to prevent this, I can think of an explanation for children. Under stressful conditions, such as war, famine, and plague, it makes sense for a child to age faster -- to race to maturity and get out of harm's way. The adaptation may have developed very early in animal (or pre-animal?) evolution, so it may be deeply embedded in our genes.
BTW, about ten years ago I was quite interested in punctuated aging -- the idea that we age in "bursts". I based this on the note that few biological processes in the developing organism are continuous; we develop and adapt in episodic bursts. It helped that there's been a longstanding cultural belief that stress and disease aged us, and it helped that I noted my dog (Molly) seemed to age in bursts.
I wonder if stress-induced accelerated childhood aging would explain why children of the 19th century seemed to have the behavior and capability of adults today. Or why today's 25 yo male seems the biological age of yesterday's 21 yo.