Each issue carries an imprimatur from
the Archdiocese of Cincinnati. Reprinting prohibited
Stem Cell Research and Human Cloning
Questions and Answers
From the Secretariat for Pro-Life Activities, U.S. Catholic Bishops' Conference
What is a stem cell?
A stem cell is a relatively unspecialized cell that, when
it divides, can do two things: make another cell like
itself, or make any of a number of cells with more
specialized functions. For example, just one kind of
stem cell in our blood can make new red blood cells, or
white blood cells, or other kinds—depending on what
the body needs. These cells are like the stem of a plant
that spreads out in different directions as it grows.
Is the Catholic Church opposed to all stem cell research?
Not at all. Most stem cell research uses cells obtained from
adult tissue, umbilical cord blood, and other sources that pose
no moral problem. Useful stem cells have been found in bone
marrow, blood, muscle, fat, nerves, and even in the pulp of
baby teeth. Some of these cells are already being used to treat
people with a wide variety of diseases.
Why is the Church opposed to stem cell research using the embryo?
Because harvesting these stem cells kills the living human
embryo. The church opposes the direct destruction of innocent
human life for any purpose, including research.
If some human embryos will remain
in frozen storage and ultimately be
discarded anyway, why is it wrong to
try to get some good out of them?
In the end we will all die anyway, but that gives no one a
right to kill us. In any case, these embryos will not die
because they are inherently unable to survive, but because
others are choosing to hand them over for destructive research
instead of letting them implant in their mother’s womb. One
wrong choice does not justify an additional wrong choice to
kill them for research, much less a choice to make taxpayers support such destruction. The idea of experimenting on human
beings because they may die anyway also poses a grave threat
to convicted prisoners, terminally ill patients, and others.
Haven’t doctors, scientists, and
commentators said that embryonic
stem cell research will lead to the cure
of many diseases?
Some have made this claim, but in fact this is largely speculation.
Embryonic stem cells have never treated a human patient,
and animal trials suggest that they are too genetically unstable
and too likely to form lethal tumors to be used for treatment
any time soon. Years ago it was said that stem cells from
embryos would be the most useful because they are so
fast-growing and versatile, able to make virtually any kind
of cell. But those advantages become disadvantages when
these cells make tumors, creating a condition worse than
the disease. Yet many supporters remain wedded to this
approach, having invested a great deal of money and effort
and hoping they can still make it work. This kind of exaggerated
“promise” has misled researchers and patient groups
before—most obviously in the case of fetal tissue from
abortions, which a decade ago was said to promise miracle
cures and has produced nothing of the kind.
Is the Church telling us to choose
the lives of embryos over the lives of
No. It is calling us to respect both, without discrimination. We
must help those who are suffering, but we may not use a good
end to justify an evil means. Moreover, treatments that do not
require destroying any human life are at least as promising—they are already healing some conditions, and are far closer to
healing other conditions than
any approach using embryonic
stem cells. The choice
is not between science and
ethics, but between science
that is ethically responsible
and science that is not.
stem cell research
this research is
banned in the
No. Embryonic stem cell
research is fully allowed in
the United States—there is
no federal law (and almost
no state law) against it. The
government has only set some limits on the number of embryonic
stem cell lines eligible for federal
funding. Supporters disappointed
at failures using these cells sometimes
blame this stem cell research “ban”
(which is not really a ban at all).
But as noted above, the much more
serious obstacle lies in the nature of
the cells, which are not working out
as some predicted.
Did the federal government
in 2001 forbid
funding any embryonic
stem cell research?
No. In fact, the federal government
gave $25 million to human embryonic
stem cell research last year. But on
August 9, 2001, President Bush said
that federally funded research would
use only embryonic stem cells
already in existence (obtained by destroying embryos prior to
that date). In this way, he reasoned, federal funds could be
used to explore this research, without encouraging researchers
to destroy new embryos in order to obtain federal grants. Some
of these existing stem cell samples have been used to create
more than 20 cell lines for research, and others remain in
storage for possible use in creating new cell lines in the future.
There is no legal limit on the amount of funding that can be
used for this avenue; if the total funding for it is relatively
small, that is chiefly because researchers are not requesting
the funds as they are finding other avenues more promising.
Has research using adult stem cells
ever accomplished anything?
Thousands of lives have been saved by adult stem cells—most
often in the form of bone marrow transplants for leukemia
and other conditions (where the active ingredient in the bone
marrow is stem cells). Today, adult stem cells have been used
to help people with Parkinson’s disease, spinal cord injury,
sickle-cell anemia, heart damage, corneal damage, and dozens
of other conditions. The danger is that this progress toward
cures will be halted or slowed by campaigns that divert attention
and resources toward embryonic stem cell research.
Can stem cells be stored in a bank?
Yes, like donated blood or bone marrow, they can be frozen
and banked. In 2003, for example, Congress approved funds to
help create a nationwide umbilical cord blood stem cell bank,
in light of the many clinical benefits being discovered from
these cells now usually discarded after live births. Many of
the embryonic stem cell samples eligible for federally funded
research under the current policy also remain frozen in banks,
to be thawed and turned into stem cell lines when needed.
What is a stem cell line?
It’s an ongoing, living colony of stem cells in a laboratory,
from which cells can be obtained for research or other uses.
Sometimes these are called “immortal” cell lines, but that is
misleading because they do eventually deteriorate. Embryonic
stem cells are said to be easier to grow in a stem cell line,
but they also tend to develop serious genetic abnormalities
associated with cancer.
What are the advantages of harvesting
donor cells from the intended
recipient of the stem cell therapy?
Because these cells come from the patient, they are an exact
match and will not be rejected by the body as foreign tissue.
Also, because no foreign substance is placed in the body, there
are fewer regulatory barriers to their medical use.
Who is funding stem cell research?
What role is federal funding playing
in determining research priorities?
Many private foundations and for-profit biotechnology companies
fund stem cell research, but the federal government (especially
through the National Institutes of Health) remains the largest
source of funds. The government’s funding priorities have a
large influence on the direction that medical research takes.
Since available research funds began being diverted toward
exploring embryonic stem cell research, some very promising
adult stem cell avenues for treating juvenile diabetes, spinal
cord injury, Parkinson’s disease, etc. have been underappreciated
and underfunded. Many advances in these fields have
emerged from other countries.
What is human cloning and how is
it related to stem cell research?
In human cloning, the DNA from the nucleus of a person’s
body cell is inserted into an egg whose own genetic material
has been removed, and the egg is then stimulated to begin
embryonic development. The resulting cloned embryo would
genetically be an almost identical twin to the person supplying
the body cell. This research overlaps with the stem cell issue.
That is, human cloning might be done to create an embryo who
will be destroyed to provide stem cells genetically matched to
a patient, so the cells will not be rejected as a foreign tissue.
But some cloning research is done for other purposes—for
example, to create embryos with devastating illnesses from the
body cells of sick patients, to study the early progress of that
disease. Most embryonic stem cell research involves embryos
created by in vitro fertilization, not cloning.
Why does the Church oppose human
Cloning is a depersonalized way to reproduce, in which
human beings are manufactured in the laboratory to preset
specifications. It is not a worthy way to bring a new human being into the world. When done for stem cell research, it
involves the moral wrong of all embryonic stem cell research
(destroying an innocent human life for possible benefit to
others) plus an additional wrong: It creates human beings
solely in order to kill them for their cells. This is the ultimate
reduction of a fellow human being to a mere means, to an
instrument of other people’s wishes.
Does opposition to cloning and
embryonic stem cell research come only
from one theological or political view?
No. Serious moral concerns about these practices have been
raised by an array of both religious and secular groups, including
some who disagree with the Catholic Church about abortion—Friends of the Earth, the United Methodist Church, etc. The
human cloning ban supported by the Church has been approved
by the House of Representatives by an overwhelming bipartisan
majority. Many other countries (including Canada, France,
Australia, Germany and Norway) have passed similar bans.
Opposition to the idea of treating early human life as a mere
object or commodity in the laboratory transcends religious
and political division.
For more information, see www.usccb.org/prolife/issues/bioethic
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