Special Harvard Commentary: The Ethical Debate Over Embryonic Stem Cells
Last reviewed and revised on May 20, 2013
By Anthony L. Komaroff, M.D.
Embryonic stem cells can turn into virtually any type of specialized cell. But because embryonic stem cells come from human embryos, they are the subject of a huge ethical controversy.
The Moral Arguments
Embryonic stem cells come from very early embryos. Such embryos:
The ethical question is simple: Is the embryo from which embryonic stem cells are taken a human life? When does life begin? Since removing the stem cells destroys the embryo, if an early embryo is a human life, then a human life has been destroyed.
One issue on which virtually all scientists and the general public agree is that creating a human clone and then trying to let that embryo grow into a human baby is unethical. Such "reproductive cloning" has been performed successfully in animals, the most famous example being the sheep named Dolly.
In 2007, cells very much like embryonic stem cells were created in both mice and humans by reprogramming specialized cells, and without creating an embryo! Since the ethical questions around human embryonic stem cells involve destroying an embryo from which embryonic stem cells have been taken, successful reprogramming in humans would be unlikely to raise ethical concerns.
The Legal Realities
There are two legal realities in the United States that affect the argument over the morality of using embryonic stem cells. The first is that abortion has been legalized by the U.S. Supreme Court — under certain conditions.
The second legal reality is that since 2001, there have been a limited number of embryonic stem cells for researchers to use. Although that limitation was eased by President Barack Obama in 2009, there still are constraints that some scientists feel are unnecessarily holding back research.
Can Scientific Research Change the Ethical Argument?
There are three possibilities that could make the ethical conflict irrelevant.
Anthony L. Komaroff, M.D., is professor of medicine and editor-in-chief of Harvard Health Publications at Harvard Medical School. Dr. Komaroff also is senior physician and was formerly director of the Division of General Medicine at Brigham and Women's Hospital. Dr. Komaroff has served on various advisory committees to the federal government, and is an elected Fellow of the American Association for the Advancement of Science.