Obesity is known to cause premature aging, and the mechanisms that underpin this process are slowly being uncovered. New research finds that bariatric surgery not only aids weight loss, it also reverses molecular aging.
Being clinically obese also hastens the aging process, a fact which, over the last few years, has been pinned down to certain molecular processes.
Earlier research has shown that obesity increases levels of reactive oxygen species (free radicals) in fat cells, leading to a shortening of the telomeres – a marker of aging.
Telomeres are structures positioned at the ends of each chromosome, providing protection to the DNA. Each time a cell divides, a small portion of the telomere is lost.
Once the telomere reaches a critical limit, the cell goes through a process of senescence (cells stop dividing permanently) or apoptosis (cells commit suicide).
Various lifestyle choices can increase the rate at which the telomeres are degraded; these include smoking, bad diet, lack of exercise, and obesity.
Obese people are known to have shorter telomeres, but they also show other hallmarks of premature cellular aging; they display higher levels of inflammation and increased volumes of inflammatory cytokines – cellular messengers which often act to make disease worse.
A recent study examined whether bariatric surgery could reverse these cellular signs of aging. The findings were presented yesterday at the Frontiers in CardioVascular Biology (FCVB) 2016 conference in Florence, Italy.
Bariatric surgery is a procedure that significantly reduces the size of the stomach. Weight loss can be dramatic; the surgery can reduce body weight by 30-40 percent over the course of just 1 year. A team of researchers from the University of Vienna, Austria, set out to discover whether the cellular processes of aging were also reversed.
Led by Dr. Philipp Hohensinner, the team studied 76 patients with an average age of 40 and an average body mass index (BMI) of 44.5 kilograms per square meter. All participants had struggled to lose weight through lifestyle changes alone and had been referred for bariatric surgery.
Blood samples were taken before the surgery, then at the 12-month and 24-month mark. Across the group, on average, BMI dropped to 27.5 kilograms per square meter – a 38 percent reduction.
As far as cellular changes were concerned, they were also clear cut. There were significant reductions in cytokines that promote inflammation, such as plasminogen activator inhibitor-1 and interleukin-6; they also charted a rise in a cytokine that reduces inflammation, known as interleukin-10.
Two years after the surgery, the patients’ telomeres were an impressive 80 percent longer in both cells and blood samples.
“These cells are replenished over time. It means that the cells we examined at 2 years were different cells in this new post-surgery environment. They had longer telomeres and appeared younger than the cells we measured before surgery. The cells seem to have less stress and are less forced to proliferate.”
Dr. Philipp Hohensinner
In addition to measuring the telomeres, the team also evaluated telomere oxidation, one of the causes of telomere shortening. After 2 years, oxidative damage to the telomeres had been reduced three-fold.
As Dr. Hohensinner concludes, “the cells appear to be getting younger” because there is less breakage due to oxidation. Being obese puts stress on the entire body. The good news is that the bodies of individuals who have undergone bariatric surgery are able to repair themselves and turn back the tide of aging.
The findings might also be applicable for other individuals who have lost weight by dieting over a longer period of time. The body, it seems, is capable of reversing this type of premature aging.