GLP-1 agonists like Ozempic were a turning point in the management of type 2 diabetes. Combined with SGLT2 inhibitors—a second class of diabetes medication—these treatments transformed outcomes for many patients. Blood sugar came under control, and many were able to reduce or eliminate insulin and blood pressure medications entirely. Weight came down. Energy levels improved. The results, for patients with both type 2 diabetes and excess body weight, were often dramatic.
Now both medication classes appear to offer a further, unexpected benefit: a meaningful reduction in the risk of dementia.
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Dementia
Let's start with an obvious question: Who is at risk? Many more than you might think. A recent analysis updated older estimates—and they're much higher than we thought. The analysis projects that 42% of Americans over 55 will eventually develop dementia [1].
And this isn't confined to the U.S. Globally, the WHO reports that dementia is the 7th leading cause of death and a major cause of disability among older people [2].
In other words, dementia is incredibly common. With an aging population and the prevalence of risk factors like high blood pressure, it promises to get worse. That's why the possibility that common diabetes medications can lower the risk of dementia is a significant development.
So what's the connection? How is a treatment for diabetes linked to dementia?
Evidence has accumulated over time that people with type 2 diabetes are at greater risk of decline in mental functioning [3]. That's because the main problems generated by type 2 diabetes are also causal drivers of dementia. Take, for example, the presence of chronic inflammation. This accelerates the build-up of plaque inside the arteries. As a result, people with type 2 diabetes have 2 to 4 times the risk of developing heart-related diseases [3].
As plaque accumulates, it restricts blood flow. This can lead to brain cells not getting enough oxygen. The resulting damage starts to impair brain function. This process is one of the major drivers of dementia. This form is called vascular dementia [4].
The other most common form of dementia is Alzheimer's disease. It also involves damage to brain cells, but through a different mechanism—accumulation of broken proteins around and inside neurons. This interferes with neuron communication, creates inflammation, and can lead to cell death [5].
Despite years of research, it is still not fully understood exactly why Alzheimer's develops the way it does. But it is clear that the disease shares several mechanisms with type 2 diabetes. Both involve insulin resistance, oxidative stress, and heightened inflammation [5].
So with type 2 diabetes sharing key dynamics with both forms of dementia, it follows that a treatment for type 2 diabetes could also affect dementia risk.
When it comes to diabetes treatments, two classes in particular are attracting the most research attention. The first is GLP-1 agonists like semaglutide, known under brand names like Ozempic and Wegovy. These medications mimic a hormone that regulates insulin and were designed to keep blood sugar levels within a healthy range [6].
They also turned out to be powerful aids to weight loss. They slow how quickly food moves through the stomach, increasing feelings of fullness. They also act on brain receptors that control appetite [6].
There are several potential benefits here when it comes to dementia risk. GLP-1 agonists increase insulin sensitivity and help reduce inflammation, preventing artery plaque buildup. They can also cross the blood-brain barrier and exhibit anti-inflammatory and antioxidant effects in the brain [5].
The second medication class is SGLT2 inhibitors. Here's how they work: the kidneys filter blood, removing glucose along with waste. Normally, a protein called SGLT2 reabsorbs the glucose back into the bloodstream. SGLT2 inhibitors block that process, so the glucose gets excreted in the urine instead—resulting in lower blood sugar levels [7].
There is also emerging evidence that SGLT2 inhibitors might protect brain health. They improve small-vessel circulation in the brain and have anti-inflammatory and antioxidant effects [8].
Clinical Evidence on These Meds and Dementia Risk
Both GLP-1 agonists and SGLT2 inhibitors are effective treatments for type 2 diabetes that show promise for addressing dementia causes. But what does the clinical evidence show?
Starting with GLP-1 agonists: an early study in 2015 tested liraglutide in mice with early-stage Alzheimer's. After four months, liraglutide delayed or partially halted memory decline [9].
Researchers then looked at humans. In one study, 38 participants with Alzheimer's were split into treatment and placebo groups for 26 weeks. Liraglutide treatment preserved the brain's ability to use glucose—a function that typically declines with Alzheimer's [10].
Though promising, the study was small. That's why a 2020 analysis of the REWIND trial was significant. It included nearly 10,000 people with diabetes and lasted over 5 years [11]. Two cognitive function tests were administered at the start and throughout. The analysis found that dulaglutide, a GLP-1 agonist, reduced the risk of cognitive decline by 14% [11].
Then came a major 2025 study. Researchers examined 9 years of health records from almost 100,000 type 2 diabetes patients without prior dementia. They compared those taking GLP-1 agonists to others. The result: a 33% lower risk of dementia among GLP-1 agonist users [12].
What about SGLT2 inhibitors? A 2024 meta-analysis looked at three observational studies and found SGLT2 inhibitors were associated with a 38% lower risk of dementia [13]. However, results varied widely—one study showed no reduction at all [13].
The 2025 study mentioned above also examined SGLT2 inhibitors. Users had a 43% lower risk of dementia compared to those using other diabetes medications [12].
There was little difference between GLP-1 agonists and SGLT2 inhibitors in terms of dementia risk reduction. Both were strongly associated with lower risk [12].
The evidence suggests the greatest cognitive benefits are seen when treatment begins early—especially in those with prediabetes or early-stage type 2 diabetes [14]. One study also found that people with heart disease or cerebrovascular disease experienced the most benefit [15].
It is important to note: almost all the research so far has been conducted in populations with type 2 diabetes. Whether these medications can help slow or prevent dementia more broadly in non-diabetic individuals remains an open question.
Fortunately, trials are underway. The Evoke and Evoke+ studies are randomised controlled trials testing semaglutide over three years in individuals with early-stage Alzheimer's disease. These trials are specifically designed to determine whether GLP-1 agonists can slow Alzheimer's progression, even in people without type 2 diabetes. Results are expected in 2026 [16].
In the meantime, SGLT2 inhibitors have shown other benefits, too. They help treat liver disease and heart failure [7], and reduce blood pressure [17].
Another intriguing finding: SGLT2 inhibitors might extend lifespan. In a mouse study, canagliflozin extended median survival by 14%—but only in males [18].
Conclusion
There is growing, compelling evidence that GLP-1 agonists and SGLT2 inhibitors—both originally designed for managing type 2 diabetes—can also reduce the risk of dementia. With more research underway, particularly in non-diabetic populations, more answers about their broader potential are expected in the coming years.
In the meantime, managing blood sugar, reducing inflammation, and protecting vascular health continue to be key strategies—not just for metabolic health, but for brain health as well. These are interconnected systems, and evidence increasingly suggests that what's good for the heart and metabolic system is also good for the ageing brain.
References
1. https://www.nature.com/articles/s41591-024-03340-9
2. https://www.who.int/news-room/fact-sheets/detail/dementia
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC8659196/
4. https://www.ncbi.nlm.nih.gov/books/NBK430817/
5. https://www.mdpi.com/2813-2564/4/1/2
6. https://www.ncbi.nlm.nih.gov/books/NBK551568/
7. https://www.ncbi.nlm.nih.gov/books/NBK576405/
8. https://pmc.ncbi.nlm.nih.gov/articles/PMC11351143/
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC4878312/
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC4877513/
11. https://pubmed.ncbi.nlm.nih.gov/32562683/
12. https://jamanetwork.com/journals/jamaneurology/article-abstract/2831976
13. https://pmc.ncbi.nlm.nih.gov/articles/PMC10363181/
14. https://journals.sagepub.com/doi/10.1177/25424823251342182
15. https://pmc.ncbi.nlm.nih.gov/articles/PMC12125485/
16. https://pubmed.ncbi.nlm.nih.gov/39780249/
17. https://cardiab.biomedcentral.com/articles/10.1186/s12933-020-01071-y
