Could Metformin Lower Dementia Risk?
By Caleigh Findley
A recent study supports the idea that metformin may have a role in dementia prevention. Studies are ongoing to provide a definitive answer.
Researchers from Boston University studying metformin and dementia found that stopping the diabetes drug prematurely was associated with increased dementia risk.
While more research is needed, the study adds to a growing body of scientific evidence suggesting a beneficial link between metformin use and dementia.
The study analyzed health data from 12,220 people who stopped taking metformin early and 29,126 people who used the medication regularly. Researchers employed a “matching” technique that compared those who stopped metformin to routine users of the same age, gender, and duration of living with diabetes.
They found that those who terminated metformin use early (for reasons aside from kidney dysfunction; some studies have found long-term metformin treatment could negatively impact kidney function in those with diabetes and chronic kidney disease) had a higher incidence of dementia compared to those who stayed on the medication.
The connection between metformin use and dementia appears mostly independent of glucose control and insulin, though “the mechanism of how metformin use influences brain health is unclear,” said Dr. Andrew Budson, chief of cognitive behavioral neurology at Boston University.
Type 2 diabetes and dementia
The answers to the metformin connection may lie in our understanding of the relationship between diabetes and dementia. Studies show that those with type 2 diabetes are at roughly a 50% greater risk of developing Alzheimer’s disease, the most common form of dementia, later in life.
Some researchers have taken to calling Alzheimer’s “diabetes of the brain.” A growing body of evidence indicates that the insulin resistance and hormone imbalances generated by diabetes can have a great impact on brain health.
This hypothesis has inspired a multitude of studies into dementia prevention using metformin, the most popular type 2 diabetes therapy. The drug works through several means, primarily through lowering liver glucose production.
“The evidence base [for metformin and dementia prevention] is still growing and evolving,” said Dr. Andrew Odegaard, associate professor of epidemiology and biostatistics at the University of California, Irvine. “These aren’t final answers.”
Enough evidence has accrued to drive a large multi-center clinical trial investigating metformin for Alzheimer’s disease prevention, called the MAP study. Results from the trial are expected in late 2026.
A diet for the mind
Beyond medication, there are lifestyle changes people with diabetes can implement to support brain health.
“The good news is that everyone with diabetes, whether they are taking metformin or not, can reduce their dementia risk by eating a Mediterranean menu of foods – particularly whole foods (not highly processed) – and engaging in aerobic exercise for at least 30 minutes each day, at least five days each week,” said Budson.
A healthy diet and exercise are touted by many dementia researchers as an effective strategy for dementia prevention. The National Institute on Aging published results this year showing the effectiveness of the MIND diet against biological signs of Alzheimer’s disease, with studies still ongoing.
“Activity and exercise are potent for controlling type 2 diabetes,” said Odegaard. He emphasized that when implementing a healthy diet, it’s best to do so in a way that is most enjoyable and sustainable for your lifestyle.
Those living with type 2 diabetes should also exercise some caution when diving into the online world of healthy living. Many questionable vitamin recommendations and other health advice exist on websites or social media.
“Unless one has a vitamin deficiency, vitamins are not helpful,” cautions Dr. Budson. “The data suggest that the best way to reduce your risk of dementia is to stay healthy, in all ways: physically, mentally, and emotionally.”
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