Contrast that with the long string of athletes who have very publicly announced they have gone to clinics, usually off shore, for unproven stem cell therapies. Those actions have probably led many families to decide to take on the expense and risk of following in their footsteps. So it was refreshing to see this long piece in the Scientific American blog by the well-respected science journalist Deborah Franklin.
Most of these athletes have received adult stem cells taken from one site in the body and injected into another site where it was hoped the cells would repair a performance limiting injury. Franklin notes that the athletes have stated that any health risk ought to be slight because the cells were their own. She quickly counters that assertion:
“That might not be such a safe bet. Numerous studies suggest that [athletes like] Colón, Nitkowski and others trying untested stem cell treatments may be risking more than they think. Even a syringe of one's own stem cells taken from one part of the body and squirted into another ‘may multiply, form tumors, or may leave the site you put them in and migrate somewhere else’ the FDA warns on its Web site. More clinical research is needed to define safety procedures, as well as how many cells of which types and what other tissue factors produce the desired results.”Most of these attempts to repair athletes involve a second, less well know, type of stem cell that resides in bone marrow, mesenchymal stem cells, which can multiply and produce all the connective tissues, including bone, cartilage, tendon and fat. The problem is, those connective tissues don’t generally have blood vessels and therefore don’t have all the different cell types that course through our blood, often carrying growth factors and other factors needed to get robust healthy growth of new tissue. Franklin used a quote from Rocky Tuan of the University of Pittsburgh to further explain:
“You can inject all the best cells, but if you don't have the right combination of healing goodies around them, it's useless.”Franklin notes that animal studies looking at these types of injuries have raised as many questions as answers. She brings that point home with a quote from CIRM-grantee and active stem cell blogger Paul Knoepfler of UC Davis:
“The term ‘stem cell’ makes it sound cutting edge and exciting, but the role of these cells in sports medicine is essentially all hype.”We have a web page that discusses issues about stem cell tourism. We also have a video in which CIRM-grantee Jeanne Loring discusses her concerns.