Scientists have been searching for decades for an effective treatment for Alzheimer’s disease.

But now a new study suggests that a breakthrough treatment has been on the market in the US since 1995.

In fact, it’s a drug with more than 48 million prescriptions filled in the US in 2010 alone. That’s because the drug treats an increasingly common disease—type 2 diabetes.

Now it looks like this blood sugar drug, metformin, might also help the brain and, in particular, might help Alzheimer’s patients.


The recent study showed two important things. The first was that metformin promoted something called neurogenesis in both mouse and human cells in lab tests. Neurogenesis occurs when stem cells produce new nerve cells in the brain. The second finding was that mice that took metformin (and, therefore, experienced this type of cell regeneration) had better memory function. To learn more, I spoke to study author David Kaplan, PhD.

To test the brainpower of living mice, researchers designed an experiment using a water maze. Some mice were injected with metformin, while control mice were injected with a placebo (saline). Mice were taught where they could find a platform within the maze that would lead them out of the water. Then the platform was moved and the mice were taught the platform’s new location. When the mice were removed from the maze and then put back in it, mice that had received the metformin had an easier time remembering that the platform had been moved.


A previous study, Dr. Kaplan told me, did show that people with both dementia and type 2 diabetes who were being treated for their diabetes with metformin and insulin had fewer dementia symptoms, compared with patients with both health conditions who were taking only insulin.

Exactly why these people experienced dementia symptom relief was unclear. However, this new research suggests that the relief may have something to do with metformin’s ability to promote neurogenesis.


Metformin is currently FDA-approved to treat only type 2 diabetes, but Dr. Kaplan said that it could potentially be used to treat Alzheimer’s in the future if the clinical trials are successful. In fact, the drug is already being prescribed off-label for weight loss, gestational diabetes and polycystic ovary syndrome.

If you or a loved one has Alzheimer’s, ask your doctor if it’s a good idea to take the drug off-label. Dr. Kaplan is a PhD, not an MD, and wouldn’t comment on the matter—so we asked an MD for his perspective. “Right now, the jury is out on the effectiveness of metformin in treating Alzheimer’s—and other forms of dementia, such as mild cognitive impairment—in humans,” said Henri J. Roca, MD, medical director of Greenwich Hospital Integrative Medicine Program in Cos Cob, Connecticut. “I would prescribe it only if a patient had some form of dementia and poorly regulated insulin or blood sugar problems.”

Could metformin cause dangerously low blood sugar in people without diabetes? “There is only about a 1% to 3% chance of this happening,” said Dr. Roca. Another rare but serious metformin risk in both type 2 diabetics and nondiabetics is the overproduction of lactic acid and a resulting electrolyte imbalance. Also, metformin can negatively interact with some drugs—for example, you and your doctor would have to be especially careful with steroids, decongestants, thyroid medications, IV contrast agents and any treatment designed to lower blood sugar. Patients with heart failure or kidney impairment may want to avoid metformin.

What about metformin preventing Alzheimer’s in high-risk people someday? It’s a possibility, said Dr. Kaplan, but only a possibility for now.


If you are interested in using natural products to help your brain maintain or gain function, ask your doctor about these supplements—gamma linolenic acid, omega-3 fatty acids and L-carnitine. These all reduce inflammation, said Andrew Rubman, ND, medical director of the Southbury Clinic for Traditional Medicines in Southbury, Connecticut, and a Daily Health News contributing editor. Inflammation, he explained, hinders the body’s ability to remove plaque, and brain plaque is one characteristic of Alzheimer’s.