There is an ongoing, often-heated debate in the world of regenerative medicine: What is the single best source of adult stem cells for regeneration? Specifically, we are talking about Mesenchymal Stem Cells (MSCs), the powerful, foundational cells that give rise to bone, cartilage, muscle, and fat.
For clinical use, the choice consistently boils down to two options for adult stem cell collection: Bone Marrow and Adipose Tissue (fat). While both are abundant and relatively accessible, some proponents of adipose-derived MSCs (often referred to in clinical settings as ASCs or the Stromal Vascular Fraction (SVF)) cling to claims of higher cell yields and easier extraction.
However, when you look past the perception and dive into the data—the clinical studies, the basic biology, and the regulatory reality—a clear picture emerges. The evidence points to one source as the superior choice: Bone Marrow Aspirate Concentrate (BMAC), which yields Bone Marrow-Derived MSCs (BMSCs). In this blog, we explore both protocols and break down the factors that matter when comparing autologous bone marrow and fat stem cells.
The simplest measure of efficacy and trust in the scientific community is the volume and depth of research, particularly clinical trials. On this front, BMSCs have an undeniable, massive lead over ASCs.
- For critical conditions like stroke and myocardial infarction (heart attack), the number of published studies using bone marrow-derived MSCs (BMSCs) outnumbers those using adipose-derived cells (ASCs) by a ratio of 7:1 to 8:1.
- While only a handful of clinical trial results have been reported for adipose cells, dozens of successful, multi-phase trials have been posted for BMSCs across a diverse range of conditions, including ALS, type I diabetes, stroke, and heart attack.
The medical community has spent decades validating the role of BMSCs. Their efficacy is reinforced, while the effectiveness of ASCs continues to be evaluated.
In the lab, in vitro comparisons of mesenchymal stem cell yield per gram of fat vs. bone marrow and differences in proliferation rates (BMSCs vs. ASCs) have yielded mixed results. But an organism is vastly more complex than a petri dish, and it is in the complexity of the body where the true biological advantage of bone marrow lies.
- Cells Homing to the "Seat of Life": When BMSCs are injected, they don't necessarily flood the site of injury, but instead, the majority of the cells re-settle in the bone marrow itself. The bone marrow is the source of your entire immune system. This location better positions them to execute their primary job: inhibiting inflammation and promoting long-term recovery. Conversely, fatty tissue is inherently more pro-inflammatory, which is a factor when examining the immunomodulatory effects of adipose stem cells.
- A Biological Bonus: Collecting bone marrow offers an invaluable benefit unmatched by adipose tissue: the simultaneous collection of two other essential cell populations:
- Endothelial Progenitor Cells: The building blocks for healthy new blood vessels.
- Hematopoietic Stem Cells: The producers of all types of blood cells in the body.
Banking BMAC offers a non-trivial opportunity to preserve a "young" version of these critical cells, a key biofunctional difference in adult stem cell sources that ASC collection simply cannot match. Furthermore, BMSCs are often cited as having superior osteogenic vs. chondrogenic potential compared to ASCs, making BMAC the preferred choice in discussions about stem cells for knee osteoarthritis and the best stem cells for cartilage repair.
The two most common arguments for choosing ASCs—that they are more abundant and easier to extract—don’t always stand up to scrutiny.
- While fat may contain a higher initial concentration of cells, MSCs require expansion in culture to achieve the therapeutic numbers needed for extended treatment.
- We often get the question: Is bone marrow harvesting painful? Bone Marrow Aspiration is a simple aspiration from the iliac crest (hip bone)—a minimally invasive procedure often completed over a lunch break.
- Liposuction for stem cell therapy procedures can be more invasive and is a considerably longer process to isolate the final SVF cells. When considering the invasiveness of bone marrow vs. fat collection and recovery time for stem cell harvest, the advantages of BMAC are clear.
When we look at both sources with respect to clinical and preclinical disease study results, basic biology, and the regulatory landscape as we set out to do, we find the reasoning for storing bone marrow MSCs unquestionably more compelling. The prime advantage of adipose MSCs is largely perceptual. Many people perceive fat as being easier to extract with less pain than bone marrow. Reputations have been staked on this, but it simply does not pass the reality test.
