A telomere is a segment of DNA on the ends of each chromatid. These are said to function like the plastic caps on shoelaces, to protect the rest of the string from fraying and sticking to one another. Evidence suggests that as we get older, and maybe as we become sicker, the length of the telomere on the end of each of our chromatids becomes shorter. For example in human blood cells the length of the telomere in the DNA of the blood cells at birth is about 8000 base pairs, whereas in the very elderly it may average as little as 1500 base pairs. (remember DNA is double stranded, so each purine molecule is paired with a pyrimidine to make a base pair). I great article for anyone wanting to understand much about telomeres is on the University of Utah web site.
I read up on telomeres today after reading a CBC news article discussing a new finding that gastric bypass surgery can lead to telomere lengthening. This is remarkable because the telomere length in a given individual is considered to be very stable over relatively short periods of time, and reversal of the gradual loss of telomere length with aging is very atypical. Is it possible that gastric bypass surgery, in addition to being a near-cure for type 2 diabetes, may lead to reversal of some genetic changes of aging?
So far in addition to dramatic weight loss it looks like gastric bypass surgery can cure diabetes in many patients and radically alters the gut flora from the type of bacteria seen in obese persons to the types seen in non-obese persons. Some people post bypass surgery have noted more mental sharpness and cognitive improvements.
I’m not trying to promote gastric bypass surgery, but it has given us a model for looking at some aspects of disease risk and aging like telomere length alterations before and after a major intervention. The earlier unexpected findings like major bacterial flora changes and reversal of diabetes long before weight loss occurs have been eye-opening and may help us choose which patients will best benefit from bypass surgery vs. other types of bariatric surgery like lap-band or gastric sleeve procedures. Stay tuned for a lot more research as we look harder at unexpected consequences of bariatric surgery.