Weight Loss May Help Slow Aging

Posted: December 15th, 2013

Chromosome Caps Called Telomeres Grew Longer in Some Patients Following Surgery

ATLANTA–Weight-loss surgery may help reverse the effects of aging on genes, according to a small, intriguing new study presented at a major conference on obesity here.

Bariatric surgery has been shown to lead to significant weight loss, averaging 50% of initial body weight or more and often dramatic improvement in diabetes and other health outcomes.

In Friday’s study, researchers from Stanford University examined a marker of aging called telomeres–caps at the end of chromosomes that prevent DNA from degrading–in a group of 51 patients who underwent gastric bypass surgery. The procedure significantly reduces the size of the stomach and re-routes part of the digestive tract.

Telomeres have been shown to be related to aging, as they grow shorter over the course of the lifespan and with the presence of disease. Their length can increase again but is generally slow to change.

The findings, presented at Obesity Week, a joint meeting of bariatric surgeons and other health professionals and obesity researchers, showed that the telomeres of over half of the patients had lengthened significantly up to a year after surgery, demonstrating for what is thought to be the first time that the surgery may reverse some of the deleterious DNA effects of obesity and disease.

Those patients who had the highest risk factors for heart disease including bad cholesterol prior to surgery exhibited the most telomere lengthening, according to John Morton, director of bariatric surgery at the Stanford School of Medicine, who conducted the study.

In addition, patients exhibited a significant weight loss of an average of 70% and improvements in cardiac risk and blood sugar, as expected.

The preliminary data need to be replicated and many questions remain, including whether telomeres are a “weathervane” that signals aging or whether their degradation actually drives aging, said Dr. Morton.

Another big question is whether telomeres are lengthened by significant weight loss in general or if there is something special about bariatric surgery. Previous work has shown that surgery has a particularly potent effect on diabetes, including near-immediate resolution of the condition in some people, that isn’t due just to weight loss.

The small number of previous studies on telomere length and weight loss have been mixed. One study that examined telomere length and weight loss was published earlier this year looking at dietary weight loss and showed mild improvements in length. Other previous work has suggested that improvements in diet and stress reduction–that didn’t necessarily result in weight loss–could also lengthen them.

The group’s next step is to “dig in” and try to understand why the telomeres lengthened, said Dr. Morton.