Mapping the Terrain—Stem Cells
Though known about for nearly fifty years, stem cells recently have been targeted as a highly useful tool for creating human therapies and cures. There are more than 200 different cell types in the human body. For instance, there are skin cells, bone cells, kidney cells, and liver cells. In a normally functioning body, cells replicate after their kind; so for example there are skin cells producing other skin cells, bone cells producing more bone cells. These are, therefore, “differentiated” cells.
Stem cells, however, are un-differentiated cells. That is, stem cells have not yet received instructions to make certain cell types. Researchers hope that by being able to direct undifferentiated cells to make the types of cells one needs for therapy, treatments might be available for a wide range of illnesses and injuries. Cells might be directed to make spinal tissue to repair damaged spinal cords or brain tissue to treat Parkinson’s. The list of potential uses for stem cells is truly astonishing.
There are two principal sources of stem cells: embryos and non-embryos (or so-called “adult” tissues). Embryonic stem cells are derived from a developing embryo at the blastocyst stage of development (5 to 7 days after fertilization). The stem cells are harvested from the inner cell mass of the unborn child. Unfortunately, the removal of the stem cells kills the embryo. This means that the use of embryonic stem cells cannot be justified ethically. Adult stem cells are derived after birth. They have been identified in bone marrow, blood, brain and spinal cord, skin, cornea and retina, gastrointestinal tract, liver, pancreas, and even fat. Retrieving adult stem cells poses no special risks to the person donating them. So, with embryonic stem cells, an unborn human being must die. With adult stem cells, no one is harmed.1
Scientifically-speaking, the jury is still out concerning which source of stem cells is the most “plastic” or malleable. There is no question that adult stem cells are the morally superior source of stem cells. What is more, adult stem cells have recently shown great promise in the treatment of diabetes, Parkinson’s disease, and spinal cord injuries, even outpacing the gains made by embryonic stem cell research.2 It is important when discussing stem cells to make the distinction between embryonic sources and adult sources of stem cells. Christians can support adult stem cell research enthusiastically, and all who hold to a biblically consistent ethic will find embryonic stem cell research unacceptable.