One of the most commonly prescribed drugs in the world may help delay cognitive decline and could even be ‘anti-ageing’.
The results of a six-year study on the drug metformin – commonly used to treat diabetes – reveal that it slows cognitive decline, mitigates the effects of diabetes on brain ageing, and lowers the dementia rates in people with type 2 diabetes.
Now, researchers want to know if it will have the same effect on people without diabetes.
“Metformin has multiple effects beyond improving blood glucose levels, at least in part, because it regulates insulin pathways that affect other pathways of cell function,” says study author Professor Katherine Samaras.
“But it may not work just through insulin and glucose pathways. It may have separate effects on cell ageing and there is some evidence showing that it affects the way cells rejuvenate.”
Type 2 diabetes is at epidemic proportions in Australia, and around 60 per cent of people with the condition will likely develop dementia.
So the findings will have a huge impact on those with type 2 diabetes, but it is hoped to have broader positive benefits.
“As they age, people living with type 2 diabetes have a staggering 60 per cent risk of developing dementia, a devastating condition that impacts thinking, behaviour, the ability to perform everyday tasks and the ability to maintain independence. This has immense personal, family, economic and societal impacts,” says Prof. Samaras.
“We were incredibly pleased to find that metformin seemed to remove the risk of diabetes on cognitive decline, and certainly on dementia development during the time we studied our participants.
“Remarkably, in those taking metformin, there was no difference in the rate of decline in their cognitive function over six years compared to those without diabetes.”
Conducted over six years by the Garvan Institute and the Centre for Healthy Brain Ageing, the study involved more than 1000 participants aged between 70 and 90, of which 123 participants had type 2 diabetes.
Metformin has been used as a frontline treatment for diabetes for 60 years.
Like aspirin, it has multiple benefits.
Studies of metformin over the past decade have revealed benefits in breast and prostate cancer, heart disease, polycystic ovary syndrome and weight management.
While the current study has revealed cognitive benefits for people with type 2 diabetes, it may also benefit those at risk of cognitive decline more broadly.
“This study has provided promising initial evidence that metformin may protect against cognitive decline. While type 2 diabetes is thought to increase dementia risk by promoting degenerative pathways in the brain and nerves, these pathways also occur in others at risk of dementia and it is possible insulin resistance may be the mediator,” says Prof. Samaras.
“To establish a definitive effect, we are now planning a large, randomised controlled trial of metformin in individuals at risk of dementia and assess their cognitive function over three years. This may translate to us being able to repurpose this cheap medication with a robust safety profile to assist in preventing against cognitive decline in older people.”
While the observational study does not provide conclusive proof that metformin can delay dementia, the results make it an intriguing medicine for future studies. The Australian Financial Review reports that the team has already secured funding to delve deeper.
“Metformin has even been suggested to be anti-ageing. The intriguing question is whether metformin is helpful in those with normal glucose metabolism. More work is clearly needed,” said senior author Professor Perminder Sachdev.
Do you or does anyone you know have diabetes? Have they been prescribed metformin?
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