A recent study has highlighted the potential of metformin, a commonly used diabetes medication, in slowing the ageing process in monkeys. Published in Cell on 12 September, the research shows that daily doses of metformin can preserve cognitive function and delay the ageing effects on various tissues, particularly the brain. This study brings forward the intriguing possibility that metformin might one day be used to delay ageing in humans.

Metformin’s Impact on Cognitive Function

In the study conducted by Guanghui Liu and his team at the Chinese Academy of Sciences, 12 elderly male cynomolgus macaques were administered metformin daily for 40 months, a duration equivalent to about 13 human years. The researchers observed that the metformin-treated monkeys exhibited significantly slower cognitive decline compared to a control group of non-treated monkeys. The neuronal activity in the treated monkeys resembled that of animals approximately six years younger, which translates to about 18 human years. This finding suggests that metformin has a notable effect on preserving brain health and enhancing cognitive functions.

Effect on Other Tissues

The study also explored how metformin affected other tissues in the body. Researchers found that the drug slowed the biological ageing of several tissues, including those in the lung, kidney, liver, skin, and the brain’s frontal lobe. Additionally, metformin reduced chronic inflammation, a key marker of ageing. The drug’s influence on these various tissues indicates a broader potential for anti-ageing benefits beyond the brain.

Mechanisms and Future Research

One of the proposed mechanisms by which metformin exerts its anti-ageing effects is through the activation of a protein called NRF2. This protein plays a crucial role in protecting cells from damage caused by inflammation and injury. Despite these promising results, it is essential to note that the study did not assess the drug’s impact on lifespan but rather focused on its ability to improve healthspan—the period during which an organism remains in good health.

Challenges and Next Steps

Although the findings are encouraging, there are several limitations. The study involved a relatively small number of male monkeys, and further research is needed to determine whether the results are consistent across different sexes and larger sample sizes. Moreover, Liu and his team have initiated a new trial with 120 participants, in collaboration with Merck, to test metformin’s effects on human ageing. In addition, efforts are underway to raise funding for a larger-scale trial involving 3,000 people aged 65–79, which aims to explore the drug’s potential in extending healthspan and improving quality of life in older adults.

Conclusion

The study provides valuable insights into metformin’s potential beyond its use in diabetes management. It opens up exciting possibilities for future research into ageing and suggests that this low-cost drug could play a role in promoting healthier ageing in humans. However, more extensive and diverse studies are necessary to confirm these findings and fully understand metformin’s impact on human health and longevity.