Long on Meds Blog
Can Common Medications Help Lower the Risk of Alzheimer’s Disease?
A new study from Washington University suggests that our immune system outside the brain may help drive some of the brain damage seen with Alzheimer’s disease. That finding led me to ask whether common medications already used for vascular and metabolic disease might also influence Alzheimer’s risk.
Can our immune system outside the brain contribute to Alzheimer’s disease?
Possibly. In a new mouse study, Washington University researchers found that immune activity beginning outside the brain could increase brain inflammation and nerve cell damage.
When the researchers interrupted that immune activity, the mice had less brain damage and better memory, even though abnormal tau protein, one of the changes seen in Alzheimer’s disease, remained in their brains.
This does not prove the same thing happens in people. But it suggests that Alzheimer’s may be influenced by processes throughout the body, not just inside the brain.
Which common medications might influence these disease pathways?
That question led me back to several medications already discussed throughout Long on Meds.
Losartan and other ARBs, commonly used to control blood pressure, have been linked in population studies with lower rates of dementia.
Metformin, one of the most commonly used medications for type 2 diabetes, has also shown encouraging signals.
GLP-1 based medications such as semaglutide and tirzepatide, used for diabetes and obesity, have attracted increasing attention because they improve weight, blood sugar, insulin resistance, and cardiovascular risk.
Pioglitazone, another medication used for type 2 diabetes, has also been studied because of its effects on insulin sensitivity and inflammation.
None of these medications has been proven to prevent Alzheimer’s disease.
Does any one of these medications clearly prevent Alzheimer’s disease?
No.
Some studies have been encouraging, but the evidence for any one medication by itself is not strong enough to say that it prevents Alzheimer’s.
That is not surprising. Alzheimer’s is a complicated disease involving blood vessels, metabolism, inflammation, insulin signaling, and the immune system.
That made me wonder whether using more than one medication might matter.
What happens when metformin and a GLP-1 drug are used together?
This is where the findings became much more interesting.
A 2026 study examined electronic health records from more than 1.5 million adults with type 2 diabetes. After matching similar patients, researchers compared more than 102,000 people taking metformin plus a GLP-1 drug with more than 102,000 people taking metformin alone.
The combination was associated with about a 54% lower observed rate of an Alzheimer’s diagnosis over time.
A separate 2026 population study found a very similar result. In that study, metformin plus a GLP-1 drug was associated with about a 59% lower observed Alzheimer’s rate compared with the study’s comparison group.
These were population studies, not randomized Alzheimer’s prevention trials. They cannot prove that the drug combination prevented Alzheimer’s. But two large studies finding a similar signal is difficult to ignore.
This is also the central idea behind Long on Meds. Diseases of aging usually develop through more than one pathway. Instead of waiting for one disease to appear and then treating it with one drug, it may make sense to reduce risk earlier by influencing several disease pathways at the same time.
We do not yet know whether metformin plus a GLP-1 drug prevents Alzheimer’s disease. But these findings are another reason to study combinations of established medications for disease avoidance.
Learn more about inflammaging and inflammatory pathways, or use Check a Medication to examine metformin, GLP-1 medications, losartan, and other therapies.