Glucosamine has been freely available in drugstores for many decades. It is widely used to treat arthritis and to prevent joint degeneration. Moreover, glucosamine is known to delay cancer growth. In addition, glucosamine reduces metabolism of nutritive sugars, as was already shown some 50 years ago.
In 2007, Michael Ristow showed that too much nutritive sugar shortens the lifespan of roundworms, a widely studied model organism in aging research. Conversely, impairing carbohydrate metabolism in these worms was capable of extending lifespan. Unfortunately, the method used in worms at that time unexpectedly appeared to be ineffective in rodents, and hence was not studied further. In the recently published study that was performed at ETH Zurich and four German research institutions, Ristow and his colleagues applied glucosamine to roundworms and found that they live around 5% longer than their untreated counterparts.
Next and most importantly, the researchers fed glucosamine to aging mice in addition to their normal diet. The mice were 100 weeks of age, reflecting a comparative human age of approximately 65 years. A control group of mice received no glucosamine while otherwise receiving an identical diet. Feeding the supplement to mice extended their lifespan by almost 10%, reflecting around 8 additional years of human lifespan. Moreover, glucosamine improved glucose metabolism in elderly mice indicating protection from diabetes, a life-threatening disease most prevalent amongst the elderly.