This article tries to shed some light on how stem cells may be able to cure diabetes in the future and why their use is controversial. It aims merely to inform and elucidate some of the controversies surrounding this area of research.

Stem cells are the basis for every type of cell in the body, they possess the ability to develop into any of the body's tissues. The National Bioethics Advisory Commission, Ethical Issues in Human Stem Cell Research, 1999 states:

"Many kinds of stem cells are found in the body, with some more differentiated, or committed to a particular function than others. In other words when stem cells divide, some of the progeny mature into cells of a specific type (eg. Heart, muscle, blood or brain cells), while others remain stem cells, ready to repair some of the everyday wear and tear undergone by our bodies. These stem cells are capable of continually reproducing themselves and serve to renew tissues throughout an individual's life. .... Although the term stem cell commonly is used to refer to the cells within the adult organism that renew tissue the most fundamental and extraordinary of the stem cells are found in the early stage embryo. These embryonic stem (ES) cells, unlike the more differentiated adult stem cells or other cell types, retain their special ability to develop into nearly any cell type."

Scientists are hoping to discover how to turn these stem cells into specific cells to replace ones that are damaged-ie to turn stem cells into insulin-producing islets. As well as potentially curing diabetes it is hoped that this technique could also treat sufferers of Parkinsons disease, Alzheimers and spinal chord injury.

The ethical challenges arise in acquiring the cells for research. The only way to harvest the cells is by destroying the embryo. This raises important moral issues in relation to the creation, definition and protection of life. At one end of the spectrum of viewpoints are those who believe that human life begins at the moment of conception and that destruction of embryos cannot be justified under any circumstances. Moving along the spectrum involves balancing the ethical commitment to cure disease and protect life, respecting embryos as a form of life whilst considering the level of protection required at different stages of embryonic development.

According to the "National Bioethics Advisory Commission Paper "Ethical Issues in Human Stem Cell Research" Maryland September 1999, human stem cells can be derived from the following sources:

• Human fetal tissue following elective abortion;
• Human embryos that are created in vitro fertilization (IVF) and that are no longer needed by couples being treated for infertility;
• Human embryos that are created by IVF with gametes donated for the sole purpose of providing research material; and
• Potentially human (or hybrid) embryos generated asexually by cloning techniques in which the nucleus of an adult human cell is introduced into an enucleated human or animal ovum.

The use of cadaveric fetal tissue to derive cell lines-like the use of organs from other dead bodies is the least controversial source of stem cells.

Many embryos that are created for fertility treatment are discarded because they are no longer required or are deemed unsuitable. Using these cells for research in the battle against disease seems, to many, justifiable as they will be destroyed in any event. Opponents of stem cell research (SCR) argue that even if the end of a life is imminent that does not confer a right to conduct lethal experiments-they liken it to experimenting on death-row prisoners. I cannot resist the temptation to comment on the all-too obvious irony of certain opponents of SCR who protest the sanctity of all human life at all costs whilst maintaining an equally passionate enthusiasm for capital punishment-George W Bush being a prime example of this.

The ethical concerns are heightened when "research embryos" are used. These are embryos created through IVF (or potentially through cloning ) with gametes provided solely for research purposes. Many people believe that embryos should not be created and subsequently destroyed purely for research.

The question of when life begins is a crucial one-do some cells in a test-tube with no hope of independent survival constitute life and does an embryo have human rights? Proponents of research maintain that an embryo doesn't have moral status and that using the embryos is justified, particularly if it is done to achieve a greater good. "I'm in favour of all embryonic stem cell research and I don't think that the human condition can afford to have it slowed in any way." "Other things being equal, there is less reason for objecting to the use of an early human embryo-a being that has no brain, is not, and never has been conscious, and has no preferences of any kind-than there is for objecting to research on rats, who are sentient beings........Research on embryos should be prohibited if there is any possibility that the embryo is capable of suffering-but no one would argue that an embryo consisting of 64 cells could be capable of suffering..."

Many argue that sacrificing some embryos is justified if it is going to save more lives in the future. . "If embryonic stem cell therapy is prohibited, then living patients are implicitly devalued by striking the balance against their needs." The ethical consequences of not allowing stem cell research must also be considered, that is, responsibility for the deaths as a consequence of not pursing a life-saving therapy may be attributed to those advocating banning research into such therapies "...if ethicists or the public would restrict the uses of embryonic stem cells, then they must bear responsibility for those patients they have chosen not to try to save by this means." A problem with this argument is does the end justify the means? Opponents of SCR draw comparisons between this type of research and the medical experiments conducted in Nazi Germany, where the benefits derived from advancing medical research were used as justification for unspeakable crimes & indeed the fact that death was imminent was also used to justify lethal experimentation.

Another consequence of banning or restricting stem cell research and eventually therapies is the potential for unregulated risky activities to be undertaken, refusing government funding for research leads to these activities ending up in private hands-resulting in even greater "commodification" of humanity. Banning this work altogether raises the spectre of a black-market in body parts and a user pays system with those able to afford it travelling to more liberal locales where they can undergo therapy "at their own risk."

Juengst and Fossell raise the question, "How shall ethicists, clinicians, and any individual concerned about these issues weigh the fate of the embryo, from which these cells are derived, against the therapeutic value to patients with real medical needs?" In a debate in the British House of Lords, over this issue, Lord Althon, stated "These are not trivial questions that preoccupy a few moral theologians. They are at the heart of our humanity." I hope that as individuals with a deeply personal interest in these issues we can consider and advance the dialogue in an informed, ethical and humane way.