What if damaged brain cells could be replaced, and memory loss could be reversed? That’s the potential some researchers see in stem cell therapy for Alzheimer’s disease. It may sound like science fiction, but this experimental approach is currently being studied as a new treatment for Alzheimer’s disease.

A myALZteam member shared a recent publication on the use of stem cell therapy for Alzheimer’s, noting, “This line of research is emerging as a new legitimate strategy for Alzheimer’s drug development.”

This sentiment reflects a growing interest in stem cell therapy for Alzheimer’s. In this article, we’ll shed light on what stem cell therapy means and how it might be used to help people with Alzheimer’s in the future. We’ll also cover what researchers have learned about it so far and the current gaps in our understanding.

What Are Stem Cells?

Stem cells are like blank slates. Think of them as cells that haven’t chosen a job yet. This means they can turn into many different kinds of cells, like brain cells (neurons or nerve cells), blood cells, or skin cells. This characteristic makes them very useful for scientists studying hard-to-treat conditions like Parkinson’s disease, various kinds of cancer, and, possibly, Alzheimer’s disease.

There are different kinds of stem cells. Some are found naturally in the body, like in bone marrow or fat tissue. Other kinds are found in human umbilical cord blood or are made in labs. Lab-made stem cells called induced pluripotent stem cells, or iPSCs, are particularly exciting because they are created by “reprogramming” ordinary adult cells, making them behave like very early, versatile stem cells again.

Some people have concerns about stem cell research because of how it started. In the past, some studies used stem cells from early embryos, which caused ethical debates. Today, however, most stem cell research uses adult cells or iPSCs, which do not involve embryonic stem cells. These newer methods are largely considered uncontroversial.

How Might Stem Cells Help People With Alzheimer’s Disease?

Alzheimer’s is a type of neurodegenerative disorder. This means that as the disease progresses, brain damage gets worse over time. One of the main problems causing this is the buildup of harmful proteins in the brain. These include amyloid plaques (clumps of a protein called amyloid beta) and neurofibrillary tangles (twisted fibers of a protein called tau). These abnormalities essentially clog the brain’s machinery and disrupt its communication pathways, leading to brain damage and the symptoms of Alzheimer’s, like memory loss and cognitive decline.

When doctors use stem cells to repair damaged parts of the body, it’s known as regenerative medicine. In the case of Alzheimer’s, the goal is to use stem cells to help fix damaged brain tissue and improve cognitive function (how well the brain works). Scientists think stem cells might help in several ways.

Replacing Lost Neurons

Some stem cells can turn into new neurons. In theory, if new neurons are created and can survive in the brain, they could replace the ones that have died, helping restore lost connections. One study found that injecting stem cells into the brains of mice with an Alzheimer’s-like condition led to the growth of new nerve cells and improved memory.

Reducing Inflammation in the Brain

In Alzheimer’s, immune cells in the brain called microglia — which normally protect neurons and remove debris — can stop working properly. Instead of helping, they can cause more damage. A 2023 study in mice showed that stem cell transplants could replace these faulty microglia with healthy ones.

Another study found that stem cell-based treatments may reset this system. Here, the researchers used a nasal spray containing material derived from stem cells in an animal model of Alzheimer’s disease. These tiny particles changed how microglia acted. They lowered harmful inflammation in the brain while allowing the microglia to clear away toxic, sticky proteins like amyloid plaques.

Certain types of stem cells, called mesenchymal stem cells (MSCs), work like little factories. They let out beneficial chemicals called cytokines, which act like messengers that help calm swelling and irritation in the body, including in the brain. Scientists also found that these stem cells can change certain brain immune cells from being harmful to being helpful. So, in short, stem cells might help quiet the immune system and stop it from causing too much damage.

Repairing Brain Tissue

Stem cells can help the brain heal by letting out special proteins called growth factors. These proteins wake up the brain’s natural repair team. In Alzheimer’s, brain cells become weak or die because they don’t have enough help. The growth factors from stem cells can protect these brain cells, helping them stay alive and work better together.

In mouse studies, stem cell treatment helped to restore memory, lower inflammation, and reduce the buildup of amyloid plaques. Some studies even showed that stem cells boosted brain activity, specifically in the areas of the brain needed for learning and memory, such as the hippocampus.

Clearing Toxic Proteins

Stem cells might help the brain by lowering the amount of harmful proteins that build up. In mouse studies, stem cells reduced amyloid plaques and tau tangles. This might happen because stem cells either turn into helpful brain cells or release substances like cytokines that help clean the brain. In some mice, stem cells even helped improve memory by helping other cells break down bad proteins.

What the Research Shows So Far

While these early findings from animal studies are very encouraging and provide a strong rationale for continued investigation, the crucial next step is to determine if these benefits translate to human beings with Alzheimer’s, rather than just mice. We still need more research in people to see if stem cells can truly repair brain tissue and improve cognitive impairment. But early findings give researchers a good reason to keep investigating.

Right now, stem cell therapy for Alzheimer’s is still experimental and mostly done in preclinical (animal) models of the disease. There are a few small clinical trials in humans. However, these are in the early stages, which means they’re mostly focused on determining safety, not effectiveness. So far, the results show that they’re safe, but we don’t know yet whether they will truly lead to meaningful improvements.

One trial in South Korea gave people with Alzheimer’s stem cells directly into the brain. No serious side effects were reported, but the number of participants was small. Other studies are happening in the United States. Researchers are watching for signs of improved cognition, like better memory or thinking. While promising, it’s important to remember these are very preliminary results from small studies. Larger, more rigorous trials are needed to confirm these findings and understand the full potential.

Is Stem Cell Therapy FDA-Approved for Alzheimer’s?

Stem cell therapy isn’t approved by the U.S. Food and Drug Administration (FDA) for Alzheimer’s. This means doctors in the U.S. can’t offer it as a regular treatment. Right now, stem cell treatment is only available through research studies. These studies are closely watched to keep people safe.

Be wary of any clinics claiming to offer stem cell “cures” for Alzheimer’s. These unregulated clinics often operate outside legitimate medical and scientific guidelines. Many of these places are not safe and not part of real scientific research. They may charge a lot of money and make promises they can’t keep. Caregivers and loved ones should know that these treatments may not work and could even cause harm.

Always prioritize open and honest conversations with your neurologist (brain doctor) or a member of your healthcare team before trying any new treatment. They can also tell you about any stem cell clinical trials you may be able to participate in once they’re available. You can search for other clinical trials online at ClinicalTrials.gov.

What This Means for the Future of Alzheimer’s Treatment

Stem cell therapy is a hopeful area of research for Alzheimer’s disease, among other conditions. It may one day help reduce memory loss and brain damage. But for now, it’s still in the early stages, and we don’t know all the risks yet or how successful it may be.

If you’re caring for someone with Alzheimer’s disease, it’s natural to hope for a new treatment. New breakthroughs in stem cell research give us hope for the future. But be cautious of unproven treatments, especially from unproven clinics.

For now, focus on what we know works today, including supportive care, FDA-approved treatments, and safe living situations. If you’ve tried everything and your condition is still getting worse, talk to your healthcare team. They can help you evaluate all your treatment options and navigate difficult decisions, such as when it may be appropriate to consider hospice.

Talk With Others Who Understand

On myALZteam, the social network for caregivers of people with Alzheimer’s disease, members come together to ask questions, give advice, and share their stories with others who understand life with Alzheimer’s.

What new and emerging treatments are you most interested in? Have you taken part in any clinical trials? Share your experience in the comments below, or start a conversation by posting on your Activities page.