The population of the world is aging, and with that aging will come many health problems. But a new study has identified a supplement that could help. GlyNAC is a combination of glycine and N-acetylcysteine. In a randomized, double-blind human clinical trial, researchers found that GlyNAC supplements improved a wide variety of symptoms of aging in people. Hallmarks of aging such as insulin resistance, inflammation, DNA damage, stem cell fatigue, mitochondrial dysfunction, oxidative stress, and cell senescence, in which cells cease to divide, all showed signs of improvement. There was also a reduction of waist circumference and blood pressure in study participants, along with better muscle strength and exercise capacity. The findings have been reported in The Journals of Gerontology: Series A.
"This is the first randomized clinical trial of GlyNAC supplementation in older humans, and it found that a wide variety of age-associated abnormalities improved in older adults supplemented with GlyNAC, while no improvements were seen in those receiving placebo," said corresponding study author Dr. Rajagopal Sekhar, a professor at Baylor College of Medicine.
Recent work by this team used a mouse model to show that GlyNAC supplements improved the function of the heart, kidneys, and liver of aged mice. Mice treated with GlyNAC had a 24 parent longer lifespan, noted Sekhar.
As we age, many parts of the body start to wear down, including the function of small organelles called mitochondria, known as cellular powerhouses. Sekhar suggested that healthy mitochondria are crucial to human health, and maintaining the health of mitochondria should be prioritized, especially as we age.
While mitochondrial function is known to run down as we get older, little is known about how to prevent or improve that situation. Sekhar's team has used mouse models to show that GlyNAC supplements can restore dysfunctional mitochondria to normal in aged mice. They have also found that mitochondrial defects are more common in older people.
In this trial, people were given GlyNAC supplements for 16 weeks. Mitochondrial function became more efficient, becoming more similar to what is seen in younger people. GlyNAC may be helping to generate younger, more efficient mitochondria. "Collectively these exciting new discoveries hold great promise for improving our mitochondrial and general health as we age," Sekhar said.
Oxidative stress can occur when levels of reactive oxygen species become too high. An antioxidant called glutathione can prevent oxidative stress, but glutathione levels drop in older people. GlyNAC supplementation seems to restore glutathione levels to normal, which reduces oxidative stress, providing even more benefit.
GlyNAC is also good because it gives our body the tools it needs to make glutathione, suggested the researchers. "It is really important to understand that this trial supplemented GlyNAC, and did not supplement glutathione. This is because our body does not get its glutathione from food, but the body has to make its own glutathione every day," explained Sekhar. Glutathione is kept in a "delicate balance" that organs maintain; "too little glutathione cannot fight the harmful oxidative stress, and too much glutathione could lead to harmful reductive stress."
The combinatorial effect of glycine and cysteine from NAC, and glutathione, may be what is so beneficial, the researchers suggested.