In the lab, we have demonstrated that various anti-ageing approaches can extend healthy lifespan in many model organisms including yeast, worms, fish, flies, mice and rats. Life extension of model organisms using anti-ageing approaches ranges from 30% to 1000%:

The methuselahs in lab: The increase in maximum lifespan in the laboratory is shown in 5 animal species, both without any interventions, and by dietary, chemical, or genetic interventions. For each organism, the impact of the increase in maximum lifespan through intervention is indicated in the graph using fold change. Source: here.

These results demonstrate that ageing is plastic, and not a fixed process. In mice, some of the most effective approaches to life extension are summarised below: Source: here.

The plasticity of ageing in model organisms that share similar metabolic physiology to us provides us good proof-of-principle that ageing can be slowed in humans. It remains to be seen how much life extension is possible, and improved biomarkers of ageing will be needed to accurately measure the effectiveness of new therapies in a reasonable time-frame.