Feeding glucosamine to aging mice improved glucose metabolism and increased their lifespan by about 10%... the equivalent to ~8 years in humans.

FTA:

The widely used food supplement glucosamine promotes longevity in aging mice by approximately 10 percent due to improved glucose metabolism. Researchers find that the compound does so ‘by mimicking a low-carb diet in elderly mice reflecting human retirees.’ In addition, the results of the study seemed to give some indication of protection from diabetes, a life-threatening disease most prevalent amongst the elderly.