Stem cell therapy has become one of the most exciting areas of modern medicine. It is a proven, lifesaving treatment for certain blood cancers and blood disorders, and researchers are investigating its role in a range of other conditions.
But a growing number of stem cell clinics are promising benefits that aren’t yet supported by scientific evidence. Patients should be wary of businesses that market stem cell treatments for dozens of diseases, rely on patient testimonials instead of scientific evidence, or sell products that are not backed by evidence from rigorous clinical trials and have not been approved by the U.S. Food and Drug Administration (FDA), says Leigh Turner, PhD, from the University of California, Irvine.
What Is Stem Cell Therapy?
Stem cell therapy is a form of regenerative medicine that uses stem cells to repair, replace, or regenerate damaged tissues. Unlike most cells in the body, stem cells can reproduce themselves and develop into specialized cells such as nerve, blood, bone, muscle, or cartilage cells. Depending on the condition being studied, stem cells may replace damaged cells, stimulate the body’s own repair mechanisms, or release substances that reduce inflammation and encourage healing.
Types of Stem Cells Used in Therapy
Scientists use several types of stem cells in research and treatment. Each has unique characteristics, advantages, and limitations.
- Embryonic stem cells can develop into nearly every cell type in the body. They are what’s called pluripotent. Because of this versatility, they are seen as a powerful tool for studying disease and developing future regenerative therapies.
- Adult stem cells, also called tissue-specific stem cells, are found throughout the body, including the bone marrow, blood, skin, fat tissue, and other organs. Their primary role is to maintain and repair the tissues in which they reside. While not as versatile as embryonic stem cells, adult stem cells are the basis of today’s most successful stem cell therapies. Hematopoietic stem cells collected from bone marrow, peripheral blood, or umbilical cord blood have been used successfully for decades in bone marrow transplants.
- Induced pluripotent stem cells (iPSCs) are adult cells that scientists genetically reprogram to behave like embryonic stem cells. This breakthrough allows researchers to study pluripotent stem cells without using embryos. They are used primarily in laboratory research and early clinical trials, but because iPSCs can often be created from a patient’s own cells, they may eventually reduce the risk of immune rejection while allowing more personalized treatments.
- Perinatal stem cells are collected from umbilical cord blood, the placenta, and amniotic fluid. Researchers are studying whether these cells may help repair tissues, reduce inflammation, and treat a variety of diseases. While interest in perinatal stem cells is growing, many advertised uses remain unproven.
Approved Uses of Stem Cell Therapy
Despite growing excitement about stem cell therapy, a limited number of treatments are considered proven and routinely used in medical practice today.
“The strongest scientific evidence for stem cell therapy is in hematopoietic stem cell transplantation,” Dr. Turner says. “Hematopoietic stem cell transplants for various cancers of the blood have a compelling scientific evidence base with rigorous safety and efficacy data from well-designed and carefully conducted clinical trials. Such transplants, combined with other treatments for cancer, have the capacity to effectively treat people who would otherwise die from cancer.”
Also known as bone marrow transplants, these procedures are routinely used to treat leukemia, lymphoma, multiple myeloma, aplastic anemia, and other serious blood disorders. Outside of these established treatments, however, most stem cell therapies remain investigational and are available only through carefully regulated clinical trials.
Depending on the condition, physicians may use the patient’s own stem cells (an autologous transplant) or stem cells from a compatible donor (an allogeneic transplant). Before the transplant, patients receive chemotherapy or radiation to destroy diseased bone marrow and make room for healthy stem cells to grow and produce new blood cells.
Investigational and Emerging Treatments
Researchers are studying stem cell therapies for Parkinson’s disease, multiple sclerosis, heart disease, type 1 diabetes, spinal cord injuries, stroke, macular degeneration, and other conditions. Some early findings are encouraging, but experts caution that promising research is not the same as a proven treatment.
“I am following with interest clinical trials testing investigational stem cell interventions for multiple sclerosis, Parkinson’s disease, and macular degeneration,” Dr. Turner told Bottom Line.
Proven vs. Unproven Stem Cell Treatments
Understand the important differences between proven, investigational, and unproven stem cell therapies. A proven therapy has demonstrated safety and effectiveness in rigorous clinical trials and, when appropriate, has received FDA approval. An investigational therapy is still being studied under carefully monitored research conditions. An unproven therapy, however, is often marketed directly to consumers before convincing evidence shows that it works.
Unfortunately, many people encounter persuasive advertising that blurs those distinctions. Be wary of businesses selling stem cell products that are not backed by evidence from rigorous clinical trials and have not been approved by the FDA, Dr. Turner advises. Furthermore, be skeptical of clinics that market a single stem cell product for numerous unrelated conditions, he adds. One important warning sign, he says, is “businesses selling one type of product as a purported treatment for a long list of clinical indications.”
Furthermore, be cautious of clinics that:
- charge patients to participate in so-called clinical studies
- offer pay-to-participate studies that have not been reviewed and authorized by the FDA
- employ clinicians without appropriate training or expertise in stem cell therapies
- use patient testimonials instead of peer-reviewed scientific evidence
- depend on aggressive or high-pressure sales tactics
- have received FDA warning letters or have a history of lawsuits or disciplinary actions.
Risks and Controversies
Even proven stem cell therapies carry some risk. Possible complications include infection, bleeding, immune reactions, failure of transplanted cells to function properly, and abnormal tissue growth. Bone marrow transplants also carry significant risks, including graft-versus-host disease, a potentially life-threatening complication in which donor immune cells attack the recipient’s tissues.
Stem cell research has also generated ethical debate, particularly surrounding embryonic stem cells. Because embryonic stem cells are obtained from early-stage embryos, some people object to their use on moral or religious grounds. Advances in induced pluripotent stem cells have helped address some of these concerns by allowing researchers to create stem-cell-like cells from adult tissue rather than embryos.
How to Evaluate Stem Cell Treatments
If you’re considering stem cell therapy, don’t rely on advertisements or patient testimonials alone. Instead, ask questions about the evidence supporting the treatment. Before agreeing to treatment, ask:
- Has the FDA approved this stem cell therapy for my condition?
- Is the treatment part of a legitimate clinical trial?
- Has the therapy been tested in peer-reviewed clinical studies?
- What are the known risks and potential benefits?
- What training and experience does the physician have performing this procedure?
- Will my insurance cover the treatment, or am I expected to pay out of pocket?
Consumers can also search ClinicalTrials.gov to determine whether a study is part of a legitimate clinical trial and discuss any proposed treatment with a specialist at an academic medical center before making a decision.
