Telomeres cap the end of our chromosomes which house our DNA. Their job is to stop any unwanted loss of this vital genetic code. As cells divide, the telomeres get shorter and shorter. Measuring their length is a way of assessing cellular aging.
People who were or had been depressed had much shorter telomeres than those who had never experienced depression. This difference was apparent even after lifestyle differences, such as heavy drinking and smoking, were taken into account.
Guess what is also strongly correlated to shorter telomeres?
Hyperinsulinemia. Type 2 Diabetes.
I have "felt old" since I was in elementary school.