Another study determined that there was an association in humans between glucosamine consumption and lower mortality rates.
Current (baseline) glucosamine and chondroitin use were associated with a decreased risk of total mortality compared to never use. The adjusted hazard ratio (HR) associated with current use of glucosamine (with or without chondroitin) was 0.82 (95% CI 0.75–0.90) and 0.86 (95% CI 0.78–0.96) for chondroitin (included in two-thirds of glucosamine supplements). Current use of glucosamine was associated with a significant decreased risk of death from cancer (HR 0.87 95% CI 0.76–0.98) and with a large risk reduction for death from respiratory diseases (HR 0.59 95% CI 0.41–0.83).So about a 20% decrease in mortality rates with glucosamine, and around 40% decrease in death from respiratory diseases. This looks to be solid data, since many risk factors were adjusted for, such as BMI, smoking, etc., and there were more than 77,000 participants.
What I would like to know is whether glucosamine extends lifespan even in the presence of a low-carb diet, or whether it would be superfluous in that case.
This also tells us that a low-carb diet is a healthy one, and probably extends lifespan on its own.