Aging is a complex biological process that has always captivated scientists, drawing them into often long research journeys to unravel the mysteries of this natural process. In our quest to understand the mechanisms that underlie the aging process, we serendipitously stumbled upon taurine in a screen performed in aged humans. Taurine is not a new molecule, it was identified in 1827 in ox bile by Tiedmann and Gmelin. Taurine’s functions or actions remained poorly understood for almost 150 years. Due to the increase in affluence in societies in the 1950s, there was an increased demand for packed pet foods. This introduction of pet foods led to increased incidence of diseases in the pets, such as cardiac failure and diabetes. One of the most striking aspects of this episode was an increased incidence of blindness in cats. According to the study published in 1975, researchers identified that retinal degeneration or blindness in these cats is caused by deficiency of a single molecule in their diet, taurine. Since then, taurine has been shown to be associated with several parameters in animals and humans. However, it was not known whether changes in taurine abundance affects aging.

 

Our results show that taurine abundance declines with age in several species. We thus sought to determine whether the decline in taurine concentration was merely a consequence of aging or whether it played a role in driving the aging process. To address this question, we began supplementing mice, worms, and yeast with taurine. Our investigations showed that mice supplemented with taurine lived longer. When we analysed organ health in taurine-supplemented mice, we saw an improved functioning of several organ systems such as bone, muscle, brain, pancreas, and the immune system. These results show that taurine supplementation helps mice live longer and healthier. Taurine supplementation also made worms live longer and healthier, and improved several organ functions in monkeys. At the cellular level taurine regulated several processes classified as hallmarks of aging in mice; Taurine suppressed cellular DNA damage, cell-replication arrest, inflammation and it enhanced protein regulation and energy generation by mitochondria in the cells. Taurine appeared to have influence on all major hallmarks of aging.

 

We further performed an association analysis of taurine and metabolites with health-related parameters in approximately 12,000 aged humans. This analysis showed that lower abundance of circulating taurine and its metabolites is associated with higher incidence of diseases, such as obesity, type 2 diabetes, hypertension, and inflammation. Conversely, exercise that is known to promote health in humans and is considered anti-aging, increased circulating levels of taurine and its metabolites.  Although these studies in humans are just associations, they are consistent with the idea that taurine deficiency could be a driver of aging in humans, too.

 

In summary, our studies suggest that taurine supplementation is a potential anti-aging intervention. Taurine increases lifespan in worms and mice, improves healthspan in worms, mice and monkeys, and changes in its abundance associates with several health parameters in humans. These studies contribute to the increasing importance of dietary molecules as regulators of health. In future, a randomized placebo controlled clinical trial is needed to find out whether taurine supplementation increases healthspan in humans as it does in lower species.