An exhaustive four year-long study has shown that metformin reduces the effect of ageing. Using a wide array of ageing indicators, the researchers found that metformin resulted in about six year regression in brain ageing. They reported their findings in Cell.
Prior research and anectodal evidence suggested that metformin had an anti-ageing effect. Given to flies, worms and rodents, the drug showed evidence of rejuvenation. People taking metformin also reported feeling younger the longer they took it for.
In a rigorous 40-month study, the researchers gave metformin to 12 elderly male cynomolgus macaques and 18 other cynomolgus monkeys the drug daily. They were aged 13–16 years, equivalent to 40–50 in human years. A control group was used, as well as middle-aged and younger controls to account for ageing effects.
The study encompassed a comprehensive suite of physiological, imaging, histological, and molecular evaluations, substantiating metformin’s influence on delaying age-related phenotypes at the organismal level.
Tissue samples were taken at regular intervals, we leveraged pan-tissue transcriptomics, DNA methylomics, plasma proteomics, and metabolomics to develop innovative monkey aging clocks and applied these to gauge metformin’s effects on ageing.
The results highlighted a significant slowing of aging indicators. A number of organs that seemed to benefit included the kidneys, lungs and the skin. The greatest effect was seen in the brain, however. Metformin exerts a substantial neuroprotective effect, preserving brain structure and enhancing cognitive ability. In this case, treated monkeys had brain activity comparable to those six years younger.
The geroprotective effects on primate neurons were partially mediated by the activation of Nrf2, a transcription factor with anti-oxidative capabilities. The researchers say that this work pioneers the systemic reduction of multi-dimensional biological age in primates through metformin, paving the way for advancing pharmaceutical strategies against human aging.
The researchers have also started a much larger phase 2 human trial, with 120 participants.