For their current effort, Morton and his colleagues focused on 51 bariatric surgery patients, with an average BMI of about 44. On average, the patients were just shy of 49 years old, and more than three-quarters were women.
The researchers saw that by the one-year mark following surgery, patients had lost an average of 71 percent of so-called "excess" weight.
Such dramatic weight loss appeared to have a positive impact on key measures of health. For example, a year after surgery, patients' levels of C-reactive protein (CRP) -- a sign of inflammation -- had plummeted by more than 60 percent on average. Those who previously had high levels of so-called "bad" LDL cholesterol also saw their numbers drop. Meanwhile, fastinginsulin levels decreased to just a quarter of what they had been pre-surgery, suggesting a lower risk for type 2 diabetes.
But blood tests conducted at three, six and 12 months post-surgery revealed that, among the group as a whole, telomere length did not change all that much.
However, patients who had relatively high levels of both CRP and LDL cholesterol before the surgery did see a significant lengthening of their telomeres, when compared to those with low CRP and LDL levels pre-surgery.
"All the patients lost weight and showed big improvements in cardiac health," Morton said. "But those who had very high inflammation and bad cholesterol before surgery were found to have longer telomeres following surgery, when inflammation and bad cholesterol went down. And the lengthening wasn't so subtle. We're talking about real, significant improvements."
"What this suggests is that some bariatric surgery patients are metabolically receptive to positive change that can improve markers for aging at a genetic level," he said.
Morton said more longer-term research is planned.
Joseph Lee, associate professor of clinical epidemiology at the Columbia University Mailman School of Public Health, in New York City, reacted to the current findings with a degree of skepticism.
"Number one, it's a very small sample of patients," said Lee, a human geneticist. "It's difficult to make too much out of this. And number two, they measured telomere length within just 12 months of surgery. Now some people show telomere lengthening with age. Even some cancer patients show telomere lengthening. So is what they're seeing a true biological effect resulting from radical surgery, or is it due to a certain amount of experimental error?