Stem cell research is a new frontier in medical science. The current public debate primarily involves embryonic stem cell research. This debate will continue as government, science and society grapple with the ethical and moral questions raised by using human embryos for experimentation. While this topic is complex, it is important to understand the basic concepts of stem cell research and the potential danger that allowing research on human embryos poses to all of us.
Q. What is a stem cell?
A. A stem cell is a cell that has the potential to develop into different types of cells. Stem cells are the basic building blocks of the human body. In embryos, these master cells develop into the 200 or so distinct cell types in the body. In adults, stem cells act as nature's repair kit to replenish existing cells when they wear out or are destroyed.
Q. Where do stem cells come from?
A. All of our bodies contain stem cells. In research, there are primarily two types of stem cells: embryonic and non-embryonic (also called "adult"). Both types are developmentally flexible. Embryonic stem cells come from five-to seven-day human embryos. In order to collect these cells, a living, human embryo must be destroyed.
Adult stem cells come from a variety of sources, including skin cells, bone marrow, placenta, umbilical cord blood and body fat. No human lives are destroyed in harvesting adult stem cells. 1
Q. Why is it wrong to destroy embryos for their stem cells?
A. Biologically, an embryo represents one of the earliest stages of human life. Human development progresses in a continuum, from the single cell to the embryonic stage, then a fetus, newborn, toddler, adolescent and adult. Embryos, whether created through in vitro fertilization, cloning or sexual intercourse, are fully human and deserve protection. The weakest and most vulnerable member of the human family — the embryo — should not be the subject of scientific experimentation. It is never morally or ethically justified to destroy one human in order to possibly save another. Advances in adult stem cell research provide both tangible hope for patients and an ethical avenue for developing the therapies they need.
Q. Where do human embryos used in embryonic stem-cell research come from?
A. Initial embryonic stem-cell research centered on destroying embryos created by in-vitro fertilization (IVF), an assisted reproductive technology. Most clinics offering IVF create additional embryos that are not implanted but frozen for use in later pregnancy attempts. Sometimes parents who have their desired number of children “donate” these additional embryos to science for destructive embryo research.
More recently, scientists have turned to human cloning for embryonic stem-cell research, creating new human life for the sole purpose of destroying it. As researchers perfect human cloning techniques, we can expect to see more young humans cloned and destroyed for this type of scientific inquiry.
Q. If the in-vitro fertilization embryos are extra and will be thrown away anyway, why not use them for research?
A. One of the biggest misconceptions surrounding embryonic stem-cell research is that there are a large number of “surplus” embryos that will be tossed out with the garbage if we don’t use them for research. That’s simply not true.
According to a national survey of fertility clinics that conduct IVF, the majority of frozen embryos—88 percent—will be thawed and implanted into their mother’s womb in a future IVF cycle. Fewer than 3 percent of these frozen young humans are released from their parents’ custody for research. If destroyed in the laboratory, these embryos might yield 150-275 new embryonic stem cell lines—falling far short of the number of lines some scientists say is necessary to advance this form of stem-cell research. 2 This “shortage” of existing embryos virtually guarantees scientists will increasingly turn to the creation of new human life for embryonic stem-cell research, either through IVF technology with donated sperm and egg, or human cloning.
Regardless of the numbers of embryos available for research, dissecting tiny humans for their cells is unethical and immoral. For instance, convicted criminals on death row would make excellent research subjects and are destined to die anyway. Why not allow scientists to conduct experiments on these men and women before they are executed by the state for their crimes? Of course, we would never allow such experiments on adult humans, but somehow embryonic humans can be dismembered in the laboratory without question.
So, when you hear advocates rationalize destructive embryo research on the basis that some embryos will die anyway, remember the old maxim: the ends do not justify the means.
Q. Since embryonic stem cells seem to get all the media attention, I assume that they are the most promising for patients. Is that true?
A. While embryonic stem cells receive more press, ongoing research indicates that developed adult stem cells are as flexible as embryonic ones and equally capable of converting into various cell types for healing the body.3 (For more evidence of adult stem cell flexibility, see What the Media Won't Tell You About Stem Cell Research.) In fact, a June 2001 National Institutes of Health report concluded that, “it is impossible to predict which stem cells...will best meet the needs of basic research and clinical applications.”4
If by “promising,” you mean in theory, some scientists argue that embryonic stem cells have the most potential. Scientists first discovered they could isolate and harvest stem cells from human embryos in 1998. 5 The fact that embryonic stem cells turn into every type of cell found in the body has lead some scientists to speculate that the flexibility of these young cells to become any cell type holds great promise for healing the human body—from possible cures for diabetes and heart disease to treatments for burns and spinal cord injuries. So far, success with animal embryonic stem cell experiments is limited and researchers have been unable to move beyond animal studies because of the unpredictability and tumor-causing propensity of these cells. It’s important to note that embryonic stem cells (human or animal) have not “cured” or treated a single human patient. To date, there are no clinical trials being conducted using human embryonic stem cells.
If by “promising,” you mean actual therapies treating patients, adult stem cells have much to offer today. Non-embryonic stem cells are successfully used on a regular basis to treat patients and have been for more than 20 years. As of June 2004, the National Institutes of Health (NIH) reports funding 330 human clinical trials using non-embryonic stem-cell sources.6 The National Marrow Donor Program has identified more than 70 treatable diseases using these cells in therapy, including breast cancer, leukemia and sickle cell anemia. 7 Researchers also have successfully treated patients with Parkinson’s disease, multiple sclerosis, heart damage and spinal cord injuries using non-embryonic stem cell sources. Adult stem cells offer tangible hope to patients today.
Q. Do you have evidence that patients are being helped by adult stem cells? I don’t hear about that much in the media.
A. That’s because most in the media are so focused on the debate over embryonic stem-cell research that they miss the real news story. Over the last two years, a U.S. Senate committee heard testimony from several patients who are directly benefiting from therapies derived from adult stem cells.
In July 2004, senators listened as Susan Fajt and Laura Dominguez described separate automobile accidents that left each woman in a wheelchair, paralyzed with spinal cord injuries. Both women are regaining muscle control and walking with the aid of braces due to stem-cell transplants from their own nasal cavities. 8 At the same hearing, Dennis Turner told how his Parkinson’s disease symptoms improved, thanks to a stem-cell transplant from his own neuron (brain) stem cells. 9 In June 2003, Keon Penn told committee members about his first-hand experience with the healing power of stem cells: a transplant of umbilical cord stem cells cured his sickle cell anemia. 10 None of these stem cell sources required the loss of human life. Unfortunately, there was a virtual media “blackout” of these stories.
For more specific examples of successful human therapies and ongoing research using non-embryonic stem cells, see Adult Stem Cells: It's Not Pie-In-The-Sky
Q. Why aren’t the media reporting on the adult stem cell success stories? Why is embryonic stem-cell research receiving all the ink and airtime?
A. In a nutshell, adult (non-embryonic) stem-cell research is not controversial, so outside of an occasional mention, it’s not viewed as part of the story. The pro-embryo research agenda of some disease-advocacy groups, teamed with vocal scientists, appears to be pushing the media coverage. The real story, according to these supporters of destructive embryonic stem-cell research, centers on federal funding limits President George W. Bush ordered in August 2001. The Bush doctrine allows unrestricted, uncapped federal funding on embryonic stem cell lines formed before that date, thereby removing the incentive to destroy new embryos for additional federal funding. Advocates for unrestricted embryonic stem cell funding vehemently oppose the Bush policy and have successfully made this issue key in media reporting.
Q. If scientists are aware of these amazing stories, why do they continue to push for embryonic stem-cell research?
A. Not all scientists support embryonic stem-cell research. Many oppose it on moral grounds because it always destroys a young human life. However, other scientists have no moral qualms with destroying embryos and argue that any moral limits on embryonic stem-cell research places religion over science.
In reality, all scientific inquiry must include moral limits. Human history is fraught with examples of atrocities and human rights violations in the name of “scientific investigation.” Horrifying experiments conducted in Nazi Germany during World War II and the Tuskegee Syphilis Experiment (1932-1972) come to mind as extreme examples of such human rights abuses. Today’s destructive embryonic stem-cell research is the latest version of non-consensual human experimentation as tiny humans are dissected like laboratory animals—all in the name of science.
Q. How many embryonic stem-cell lines are eligible for federal funding?
A. There are approximately 78 lines created before August 9, 2001 that qualify for federal funding under the Bush policy. More than 20 are approved by the NIH, with more expected as they become available and ready for research. 11 In August 2001, many of these lines were in early stages of development and not yet ready for distribution.
Q. But, the Bush Administration policy equals a ban on embryonic stem-cell research, right?
A. No, embryonic stem-cell research is legal and funded in both the private and public sectors. States have the liberty to fund (or not fund) any form of stem-cell research. In fact, in 2003 under the Bush Administration, the NIH spent nearly $25 million on embryonic stem-cell research and plus an additional $190 million on non embryonic stem-cell research projects. 12 Under the Bush Administration, the government also plans to spend another $18 million to accelerate the development of the pre-August 2001 existing lines that qualify for federal funding. 13
Carrie Gordon Earll is the Senior Policy Analyst for Bioethics at Focus on the Family and a fellow with the Center for Bioethics and Human Dignity.
(This page was originally posted on September 17, 2003.)
