Feature Article

Stem Cell Research

Rabbi Professor Avraham Steinberg, MD

Presented at the Seventh Miami International Conference on Torah and Science, 12-15 December 2007

The Science of Stem Cells

The natural course of reproduction involves the fertilization of an egg by a sperm, after which the egg divides and within about five days forms a mass of cells known as a blastocyst.

The uniqueness of these cells lies in their ability to divide and differentiate into all the types of cells of which the human body is composed. That is why they are called “stem cells.” They are the stem and root of all other cell types.

Today, a blastocyst can be formed from mature cells. The nucleus of the mature cell is extracted and implanted into an egg from which the nucleus has been removed. The blastocyst still retains its ability to differentiate, but the cells that then develop will have the identical genetic material as the original mature cell. This process is known as cloning.

Theoretically, cloning could be used to reproduce human beings. Reproductive cloning is a problem with a unique set of halakhic and ethical issues beyond the scope of this article. I am going to discuss another use of cloning, which involves growing cells to the blastocyst stage and using stem cells from the blastocyst for the purpose of scientific research or medical treatment. This process is known as therapeutic (rather than reproductive) cloning.

Stem cells are critical to the research of degenerative diseases, which have become much more prevalent as the average human life-span has been extended to eighty years and more due to improved hygiene and medical care. Generally, cells that have been affected by such diseases as Alzheimer’s, Parkinson’s, and diabetes cannot be replaced. Once a part of the brain dies, it can never be recovered or replaced, so that the symptoms can be mediated but there will never be a true cure. Or, in the case of diabetes, the insulin-producing cells in the pancreas that have died or degenerated and cannot produce insulin properly cannot be replaced. A person can be treated with insulin, but the proper cell functioning will never be recovered.

With stem cells, on the other hand, it would be possible to produce insulin-producing cells and implant them into the pancreas of a diabetic patient and hence cure his diabetes. If these cells were to be produced from a cloned blastocyst of the patient there would be no immunological reaction. Similarly, whole organs might be produced from stem cells, and hence there will be no need for organ donations. If the organs were produced from a cloned blastocyst there would be no rejection, and the patient would have a fully functional organ for years to come.

Sources of Stem Cells

Where can these precious blastocysts be attained? Actually, there are millions of such samples in hospital freezers throughout the world. They are the remnants of a very typical fertilization treatment called in vitro fertilization (IVF).

In a typical scenario, a couple will turn to a fertility clinic for IVF and will have some twenty eggs extracted for fertilization. The eggs are then fertilized with the spouse’s sperm and are replanted in the woman’s womb. However, twenty eggs cannot be implanted in a woman’s womb. One, two, or at most three eggs per implantation is usually the limit. So if the first implantation is successful, and the couple does not want to have any more children, there will be seventeen fertilized eggs which are of no interest to the mother.

In the United States there are currently over one million such unwanted fertilized eggs; even Israel has some thirty thousand such eggs stored in freezers. What should be done with these eggs?
The eggs could be stored in freezers for eternity or thrown in the garbage; but researchers can use these unwanted eggs for the production of stem cells. This is currently the most frequent source of blastocysts.

While blastocysts could theoretically be created for the purpose of stem-cell harvest, the current supply of unwanted eggs provides enough material to make this unnecessary.

Attitudes toward Stem Cell Research around the World

For all the promised benefits of stem cells, there are still many roadblocks that must be surmounted in order to make the technology a medical reality. First of all, the technology is far from being mature enough to allow the sort of stem cell therapies that are envisioned. But there are also ethical, religious, legal, and other issues that need to be resolved—including on the political front.

One of the fundamental issues being dealt with is the question of when does life begin. In other words, is this blastocyst outside the womb—aged five days from conception—a living being, a human, or a creature at all? Is it an embryo, a pre-embryo, or something else altogether? Whether we define the blastocyst as a human being has profound implications for stem cell research.

Now, this is not a scientific question. There is no way that science can answer the question, “When does life begin?” or tell us how to define what is or is not human. That is a question for theologians, philosophers, even legislators, or perhaps for society as a whole to answer. Torah-observant Jews turn to the halakhah (Jewish law) for the answer.

There are a variety of opinions that have been suggested toward labeling a certain stage as the beginning of life. In fact, one can find an opinion for just about any stage along the process of human embryogenesis as the beginning of life: conception, implantation in the womb, fourteen days after conception when new cells begin to be formed, and so on.

There are secular ethicists who claim that a blastocyst is a human being. The truth is, I find it very difficult to understand how a secular person looking at a mass of cells smaller than the dot at the end of this sentence, with a remote possibility of becoming life, could say: “This is a human being.” But the fact remains that some do hold that opinion.

There is no question about the scientific importance of stem cell research. Scientists from around the world have agreed that the therapeutic potential of stem cells is so great that any and all restrictions (other than the normal ethical guidelines for biological research) should be removed.
The legislative approach has been very different, particularly, as we will see, in countries where the Catholic Church exerts a large influence on public policy.

Stem Cell Policies in the United States

During the presidency of George W. Bush, the United States had a rather strange policy toward stem cell research. President Bush, being a religious Protestant, felt that the destruction of a blastocyst constituted murder. There was no law banning stem cell research, but President Bush prohibited federal funding for the research and even vetoed a Senate resolution to allow it.

But it gets more complicated. Bush allowed funding for research on any blastocysts that were in existence prior to August 9, 2001, but prohibited funding for lines developed after that date. As if to send the message: “OK, you’ve done something wrong, but since it’s already there we might as well continue to do the research on it. But don’t try it again!”

At that time there were sixty-four stem cell lines around the world, which is absolutely insufficient for any reasonable amount of research. Many of these lines were actually derived from the same source, and many proved defective.

Some states, including New York, California, and others, enacted laws providing funding for stem cell research independently of federal funds, as a way of circumventing the ban.

Soon after Barack Obama took office as president, he reversed the policies of the Bush administration and paved the way for full US federal funding of stem cell research.

Stem Cell Attitudes Elsewhere around the World

Germany presents an interesting situation in a different way. The German government prohibits the use of German stem cells for research, but permits researchers to use stem cells imported from outside of Germany. So research on non-German stem cells is funded, while research on German stem cells is a criminal act. One can only suppose that such inconsistent legislation has its roots in the terrible pseudo-science practiced during the Holocaust.

In many other European countries and in Israel, research on excess fertilized eggs is permitted. As with many other countries, reproductive research on stem cells is not permitted in Israel, but research aimed at providing medical treatments is permitted.

As mentioned before, the Catholic Church is one of the most vociferous opponents of stem cell research. According to Catholic dogma, once an egg is fertilized, whether or not it is currently in the uterus, it is considered a human being and its destruction constitutes murder. Catholics around the world are waging legislative battles to outlaw stem cell research, and they have been successful in many countries.

Other religions and denominations have other positions: the Protestant position is mixed, while Islam generally permits it, following a trend on the part of Islamic decisors to concur with Jewish halakhic viewpoints on issues of modern technology. As we shall shortly show, the Jewish opinion is that stem cell research is indeed permissible.

Halakhah: Attitudes and Facts

First, a word of introduction about the halakhic attitude toward modern technological developments. There seems to be a trend among certain segments of the religious community today to adopt as many stringencies as possible. I want to take issue with this restrictive attitude of “forbidden unless proven otherwise.”

I base my position on the ruling of the Tiferet Yisrael in Massekhet Yadayim that no justification is needed to permit something for which there is no explicit prohibition. In other words, that which is already forbidden by halakhah is forbidden, but the rest of human experience is automatically permissible. Hence, if neither the process nor the outcome of a new technology is prohibited, it should be permitted. Now, we must get into the particulars of the stem cell issue.
“Playing G-d”

One objection that has been raised in connection to stem cell research but also in general to a wide range of technologies is the concept of “playing G-d.”

This term has no Jewish significance, but it has received a certain amount of attention in popular culture. The gist of the argument is that by taking a stem cell that G-d created to develop in a certain way, and transforming it so that it develops in a different way, we are usurping power from the A-lmighty and hence ”playing G-d.”

I believe that this is utter nonsense. After all, from a scientific point of view, no new being is created. Judaism believes that G-d created the world ex nihilo, from nothing, which is certainly not something any scientist, no matter how talented and creative, could do. Science is about discovering or revealing aspects of G-d’s natural universe that were not previously known. So a scientist researching stem cells is utilizing the properties that G-d endowed these cells with for the benefit of humanity. Only G-d can create something from nothing. This is a power that no human being is endowed with.

In fact, the scientific revelations coming from stem cell research and other areas should serve to heighten our appreciation of G-d’s power. In stem cells we see tremendous capabilities that were designed by a Planner and inscribed in the very fabric of life. Any mature observer would have to conclude that this constitutes evidence of Creation by a Creator.

So no serious consideration should be given to the claim that this research constitutes “playing G-d.” The more serious question regards the way we are interfering with Nature, and whether the possible benefits might not be outweighed by the risk of some obscure detrimental outcome that we cannot as of yet foresee.

I would suggest that the view of the halakhah on this question is that such advancement is not only permitted but required. As an example, we may take the discussion in the Talmud regarding the practice of medicine in general. Bava Kama 85b says that a physician is allowed to practice only because of the verse (Exodus 21:19), “He shall surely pay to heal [the injured party].” Perhaps the Talmud Sages felt a need to quote Scripture to permit the practice of medicine in order to dissuade the type of reasoning mentioned above.

After all, it could be argued that a physician is interfering with G-d’s plan to cause illness. As Rashi asks, “If G-d smites, can man heal?” To that, the Talmud says yes, we are allowed to heal. The Shulhan Arukh even commands us to heal. Rather than interfering with G-d’s plan, the halakhah understands the practice of medicine as a process of cooperation and partnership with G-d in improving His world.

The final verse in the Torah account of the Creation states, “For on this day [Shabbat] G-d rested from His Creation, that He Created to be done” (Genesis 2:3). This means that G-d did not create the world with the intention that no additions would be made. Rather, the Creation is “to be done,” to be continued by humankind. G-d put it in our hands to take the initiative, whether to provide shelter or clothing or any other human necessity or luxury.

What some might consider “interference” with G-d’s world is actually an opportunity for us to take an active role in cooperating with G-d’s Divine plan. We can’t move blindly ahead. We need to have halakhic decisors—well versed in the traditional literature as well as the relevant science—involved in every step along the way.

A Halakhic Approach to the Stem Cell Issue

Now, to return to the issue of stem cells. I will present my views, which are based on discussions with Rabbi Shalom Elyashiv.

First of all, halakhah certainly does not share the Catholic position that life begins at conception. Halakhah views the beginning of life as a series of stages. Life is not considered to be fully begun until birth. The clearest evidence of this position comes from the laws of murder, where a person who kills a newborn child is considered a murderer and is liable for capital punishment, but one who kills something prior to birth is not considered a murderer in the full sense of the word.

Another important stage in halakhah takes place forty days after conception. Prior to the fortieth day, the embryo is “mere water,” whereas afterward it is to be thought of as a human being for certain considerations. The distinctions and disagreements regarding a fetus after forty days are beyond the scope of this article, but all halakhic authorities would concur that it is considered less than a full human being, because the mother’s life takes precedence over that of her unborn fetus.

Another issue is the fundamental difference between an implanted embryo and one which is in a test tube outside the womb. The Catholic approach accepts no such distinction, but from a halakhic perspective a “test tube embryo” does not have the status of a human being. When considering that research on stem cells holds the promise of saving millions of fully human beings, the destruction of a blastocyst must be seen as permissible.

Another related issue is a procedure known as pre-implantation genetic diagnosis, or PGD. In such a procedure, eggs are extracted from a woman and fertilized by sperm as per standard IVF procedure, but the fertilized eggs, prior to being returned to the womb, can be tested for genetic diseases. For example, a couple with a genetic disposition to having children with Tay-Sachs—a debilitating and ultimately fatal disease—might have each egg tested for the Tay-Sachs gene. Only those that are Tay-Sachs free would be implanted.

Again, the Catholic position would prohibit disposing of any eggs which were found to test positive for Tay-Sachs, but halakhah considers these eggs to be “mere water.” They have no human personality, no human identity, and there is no problem with destroying them, while allowing the couple to give birth to a healthy child.

A similar case involved pre-implantation genetic diagnosis for a woman who carried the gene for neurofibromatosis, a genetic mutation with a number of serious negative effects. Rabbi Elyashiv permitted this woman to conceive through the procedure of PGD.

The Shaare Zedek Medical Center has PGD facilities, which in 2006 alone brought twenty-three healthy children to couples who had previously given birth to very sick children. Of course, PGD can be abused by parents who want to choose the gender or even the eye color of their offspring. While this type of misuse of PGD would clearly be prohibited by halakhah, there is a large grey area which needs to be given serious consideration.

The general guideline is clear, however: The halakhah sees life as beginning in stages, and the use of cells from the earliest stages to promote the health and welfare of humanity or particular individuals is not merely permissible but is a serious obligation.