A new study by researchers at the Buck Institute for Research on Aging in Novato suggests that a dietary supplement bodybuilders use might help stave off some of the ravages of the aging process and even extend lifespan somewhat.
The study conducted on middle-aged mice found that consumption of the naturally occurring metabolite alpha-ketoglutarate (AKG) boosted the healthspan of the mice by 40 percent and increased the lifespan of some of the mice by about 12%. Female mice in the study seemed to benefit more from the supplement than male mice.
In the study, 18-month-old mice, about 55 years in human years, were fed a food that included AKG as 2% of their diet for up to 21 months, or until they died.
In a statement, Azar Asadi Shahmirzadi, a postdoctoral fellow at the Buck Institute and lead scientist on the study, said fur color and coat condition were dramatically improved in the female mice, which also saw an improvement in gait and a curvature of the spine often seen in aging.
Asadi said male mice treated with AKG were better able to maintain muscle mass as they aged, had improved gait and grip strength, less curvature of the spine, fewer tumors and better eye health.
Gordon Lithgow, a Buck professor and senior author of the study, said, “In this study, the treated middle-aged mice got healthier over time. Even the mice that died early saw improvements in their health, which was really surprising and encouraging. The nightmare scenario has always been life extension with no reduction in disability.”
Holly Brown-Borg, a researcher on aging at the University of North Dakota, said, “This is a really interesting study that was based on data found in C. elegans worms. They’ve taken it further.”
In 2014, researchers reported that the AKG molecule could lengthen the lifespan of tiny Caenorhabditis elegans worms by more than 50%.
Another researcher on aging not involved in the study, Matt Kaeberlein of the University of Washington, Seattle, said, AKG isn’t the first molecule shown to extend life and healthspan.
“But this is the first time it is a common metabolite that is already widely used, at least in the bodybuilding community,” Kaeberlein said.
AKG is a naturally occurring substance that organisms use to break down food to create energy. Previous studies have demonstrated that levels of AKG in the body can drop 10-fold as humans age.
Brown-Borg said, “One of the great things about this study is the safety record of this particular factor is really high.”
She said studies have shown that the drug rapamycin produces even more dramatic improvements in life and healthspan, but rapamycin is believed to suppress the human immune systems and might be a risk factor for diabetes.
Kaeberlein said the study is a step forward in the “mechanistic understanding of biological aging.”
Asadi said that treatment with AKG promoted the production of interleukin 10, which has anti-inflammatory properties.
“Chronic inflammation is a huge driver of aging,” Asadi said. “We think suppression of inflammation could be the basis for the extension of lifespan and probably healthspan.”
Brown-Borg said the study was “well-controlled and well-designed,” although she would have liked to have seen the amount of AKG present in the mice’s bodies measured both at the beginning and end of the experiment.
Buck professor Brian Kennedy, senior co-author of the study, plans to test AKG on human volunteers at the Center for Healthy Longevity at the National University of Singapore, where he is the director.
“This opportunity will allow us to go beyond anecdotal evidence,” Kennedy said.
Kennedy, Lithgow and Asadi all own stock in Ponce de Leon Health, a Florida-based longevity company focused on reversing epigenetic aging. The company already sells a formulation of AKG that bears the trademarked name Rejuvant. A 30-day supply of Rejuvant tablets can be purchased online for $150.
Regarding the practice of scientists investing in areas in which they are doing ongoing research, Kaeberlein said, “This is something that has become relatively common in science. I’m not going to weigh in on whether it is a good thing or a bad thing.
“I know the authors very well, and they’re very good scientists, so personally I don’t have any concerns about the quality of this work.”
Brown-Borg said, “This has been going on in the field of aging for many years.”
But neither Kaeberlein nor Brown-Borg said they plan on taking AKG any time soon.
“I’m unlikely to take AKG until I see some compelling clinical data showing benefits,” Kaeberlein said. “It is my opinion that AKG is likely to be safe but it is possible there are side effects.”
Brown-Borg said, “I’m a skeptic. Personally, I wouldn’t do it.”