Can Diabetes Treatments Help Lower Dementia Risk?

People with type 2 diabetes are more likely to develop Dementia as they age. Scientists believe this may happen because high blood sugar can damage blood vessels and increase inflammation in the brain. The good news is that some diabetes treatments may help protect the brain as well as control blood sugar.

Researchers are now studying whether certain diabetes medicines can lower the risk of Alzheimer’s disease and other types of Dementia. Many of these studies are based on large clinical trials or reviews of patient records from health systems around the world.

Why Diabetes and Dementia Are Connected

Type 2 diabetes affects how the body uses insulin. Over time, high blood sugar can harm the heart, kidneys, nerves, and brain. Studies have shown that people with diabetes have a greater chance of memory problems and Dementia later in life.

Doctors think several things may explain this link:

• Damage to blood vessels in the brain

• Long-term inflammation

• Problems with insulin signaling in brain cells

• Increased risk of stroke and heart disease

Because of this connection, researchers are asking an important question: Can diabetes treatments also help protect the brain?

Metformin: The Long-Used Diabetes Drug

Metformin is often the first medicine doctors prescribe for type 2 diabetes. It lowers blood sugar by helping the body use insulin better.

Some earlier studies suggested metformin might help protect memory and thinking skills. Scientists believed it could reduce inflammation and improve brain energy use. However, newer research has shown mixed results. Some retrospective studies found little difference in Dementia risk among people taking metformin compared with other treatments. Researchers now believe metformin may provide some brain benefits, but the evidence is not yet strong enough to say it clearly lowers Dementia risk. Even so, metformin remains an important and effective treatment for controlling blood sugar.

GLP-1 Receptor Agonists: A Promising New Option

One group of medicines getting a lot of attention is called GLP-1 receptor agonists, often shortened to GLP-1 drugs. These medicines include semaglutide and liraglutide. GLP-1 drugs help the body release insulin after meals and can also help with weight loss. Researchers have discovered these medicines may also affect the brain.

In a large retrospective study published in BMJ Open Diabetes Research & Care, researchers compared people taking GLP-1 drugs with people taking metformin. The study included more than 87,000 matched patients in each group. The researchers found that people taking GLP-1 medicines had a lower risk of overall Dementia, Alzheimer’s disease, and non-vascular Dementias. The strongest benefits appeared in older adults and women.

Scientists think GLP-1 medicines may help by:

• Reducing inflammation in the brain

• Improving blood flow

• Helping brain cells use energy better

• Crossing the blood-brain barrier and acting directly on the brain

Although the results are exciting, researchers say more randomized clinical trials are needed before doctors can say these medicines directly prevent Dementia.

SGLT2 Inhibitors and Brain Health

Another newer class of diabetes medicine is called SGLT2 inhibitors. These medicines help the kidneys remove excess sugar from the bloodstream. Recent studies suggest SGLT2 inhibitors may also lower Dementia risk.

One large observational study from South Korea followed more than 220,000 adults with type 2 diabetes. Researchers compared people taking SGLT2 inhibitors with those taking another diabetes medicine called a DPP-4 inhibitor. The study found that people taking SGLT2 inhibitors had:

• A 35% lower risk of Dementia

• A 39% lower risk of Alzheimer’s disease

• A 52% lower risk of vascular dementia

Researchers are still learning why these medicines may protect the brain. Some experts believe the drugs improve heart and blood vessel health, which may also improve brain health.

What Do Large Reviews Show?

Scientists often combine many studies together in what is called a meta-analysis. This helps researchers look for patterns across very large groups of patients. A 2025 meta-analysis reviewed 18 observational studies involving more than 3 million people with type 2 diabetes. The researchers found that both GLP-1 receptor agonists and SGLT2 inhibitors were linked to lower Dementia risk. The analysis showed:

• GLP-1 drugs were associated with lower rates of Alzheimer’s disease

• SGLT2 inhibitors were linked to lower rates of all-cause Dementia and vascular Dementia

• Older adults seemed to benefit the most

Still, the researchers warned that observational studies cannot fully prove cause and effect.

What This Means for Patients

Right now, no diabetes medicine is officially approved to prevent Dementia. But researchers are hopeful. The evidence suggests that newer diabetes medicines, such as GLP-1 receptor agonists and SGLT2 inhibitors, may offer additional brain benefits beyond blood sugar control.

Doctors still choose diabetes treatments based on many factors, including:

• Blood sugar levels

• Heart disease risk

• Kidney health

• Weight goals

• Side effects

• Cost and insurance coverage

Patients should never change medications without speaking with a healthcare provider.

Looking Ahead

Scientists are continuing to study how diabetes affects the brain. Future clinical trials may help doctors better understand whether some diabetes medicines can truly slow or prevent Dementia.

For now, the best ways to protect brain health include:

• Managing blood sugar

• Staying physically active

• Eating a healthy diet

• Controlling blood pressure

• Getting enough sleep

• Staying socially and mentally active

As researchers learn more, diabetes care may someday help protect both the body and the brain.

Sources

1. Evaluating GLP-1 receptor agonists versus metformin as first-line therapy for reducing dementia risk in type 2 diabetes. BMJ Open Diabetes Research & Care, 2025.

2. Diabetes medications and dementia risk: Comparisons of SGLT2 inhibitors, GLP-1 receptor agonists, and metformin. Journal of Diabetes and Its Complications, 2025.

3. Systematic Review and Meta-analysis of the Association of SGLT2 Inhibitors and GLP-1 Receptor Agonists With Dementia Risk. Diabetes Journal, 2025.

4. Comparative effectiveness of glucagon-like peptide-1 agonists with other antidiabetic drugs on dementia risk in older adults with type 2 diabetes. The Lancet eClinicalMedicine, 2024.

5. Type 2 diabetes drug associated with 35% lower risk of dementia, study finds. The Guardian, 2024.

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