Despite the many benefits promised by the recent progress in stem cell research, a number of disadvantages and risks remain both in the theoretical and scientific fields.
- Religious groups claim that because embryonic stem cell research requires the subsequent destruction of the embryos used, it is a form of abortion. They sustain that creating embryos for the sole purpose of commercial use, followed by their disposal is morally unacceptable, and strongly oppose the area of study while adult and cord stem cells are readily available instead.
- With any developing form of medical research, the biggest practical risk is the unknown. Because stem cells injected into a patient are permanent, long term side effects may not be fully understood for years. A French study ten years ago found that recipients of genetically altered bone marrow transplants developed leukemia years after their allegedly successful transplants had cured their severe combined immunodeficiency
- one of many examples demonstrating the possibility of long term unforeseen consequences to treatments like these that don’t fade the way most medicines do with time.
- Significant embryonic stem cell research done on rats with the California-based research company “Geron” found successful curing of paralysis, with the appearance of small cysts in the area near the site where the embryonic cells were injected – While research claims the cysts are harmless and water filled, the implications of a similar occurrence in humans over a long period of time remains questionable.
- A number of studies have found the injection of embryonic stem cells to result in minor miscalculations resulting in the growth of strange objects such as teeth, bones and hair in areas where they were not intended, often resembling tumors. With embryonic cells, these growths continue for the remainder of the patient’s life.
- Approximately 20% of rats injected with embryonic stem cells later die from some form of cancerous tumor
Brown countries have the most liberal policies on human embryonic stem cell research, whereas countries like the United States and those shown in yellow and gray have either restrictive policies or no policy at all (1).