Of the 80 treatments and cures which have come about from stem cells, all have come from adult stem cells – not embryonic ones.
As seems to be the case with complicated issues, any side of a debate will attempt to over simplify the issues involved. If it wasn't for embryonic stem cell research, there never would have been any adult stem cell advancements. We didn't know how to manipulate adult stem cells until we figured out more about them, specifically using embryonic stem cells.
For instance, these papers are what started our understanding:
Also, there is a great deal of argument about the full efficacy of the adult stem cells.
3 . Adult stem cells are like supporting actors in the quest for stem cell treatments.
Adult stem cells are more specialized cells that arise from embryonic stem cells. Also known as tissue-specific stem cells, they are present in adults – but contrary to their name, they’re also found in children, newborn infants and developing fetuses. They have the ability to make one or two kinds of cells, such as blood and immune system cells, brain or muscle cells. Adult stem cells have a more limited capacity to replace themselves than do embryonic stem cells.
The full article does a good job of talking about the reasons for embryonic research versus adult stem cell research.
SUPPLEMENTAL INFO: (This is not so much a response to the question, but rather more information as to why it is important to continue embryonic stem cell research. The reason this is included is that generally the claim in the question is made because they wish to discontinue said research.)
Why is embryonic stem cell research important?
Research with embryonic stem cells may lead to new, more effective treatments for serious human ailments and alleviate the suffering of thousands of people. Diseases such as juvenile diabetes, Parkinson’s disease, heart failure and spinal cord injuries are examples.
Why do embryonic stem cells hold such promise?
They can develop into any cell type in the body. They can form unlimited quantities of any cell type in the body. They will help us understand inherited diseases by allowing us to study human cells bearing the exact genetic defects that cause disease in patients. They will allow us to discover safer and more effective drugs by making it easier to screen drug candidates.
What has stem cell research accomplished?
Bone marrow transplants have been performed for decades and involve the infusion of adult stem cells. Research based on embryonic and adult stem cells has yielded promising results for the treatment of Parkinson’s disease and diabetes Stem cell research also has generated new knowledge about basic cell mechanisms that is critical to understanding the causes of disease, such as cancer.
Some have criticized embryonic stem cell research by arguing that adult stem cells have delivered more treatments, but that observation is misleading. While adult stem cells have been studied for decades, human embryonic stem cells were first isolated in 1998. There has not yet been time to develop new therapies using embryonic stem cells.
The overwhelming majority of stem cell scientists believe that to make the most rapid progress against disease, researchers must use all the weapons in their arsenal. That means using both embryonic and adult stem cells.
How long will it take for human embryonic stem cell research to yield medical treatments?
We can’t say how long it will take to find new treatments for any specific disease using embryonic stem cells. Biomedical research typically has a time frame of 10, 20, even 30 years. Fourteen years elapsed between the first unsuccessful clinical trial of bone marrow transplantation and the first successful transplant among unrelated patients. Now bone marrow transplants are widely touted as the best example of a successful stem cell therapy.
Biomedical research takes a long time, but the sooner the research starts, the sooner it will yield new insights and new treatments. If research were stopped by uncertainty, we never would have developed blood transfusions, cardiac bypass surgery, insulin therapy for diabetes, kidney dialysis, antibiotics, organ transplants and many other treatments we now take for granted.
So note that in this emotionally charged issue, people will tend to hyperbole and appeals to emotion in an attempt to shore up their argument over the other viewpoint. As even the University of Michigan states, those positions are misleading. Although it is notable that the generation of adult stem cells was motivated by a scientist with religious reasons for doing so, and overall, I find that his accomplishment is commendable.
Embryonic stem cells improve sight of legally blind women, CNN.com, 23 January 2012:
Two women with untreatable eye diseases said they had dramatic improvements in their vision after injections of human embryonic stem cells, making it the first documented time these controversial cells have helped someone.
Also, as pregnant mice benefit from fetal stem cells, the same might occur in pregnant humans.
Stem cell treatment for parkinsons disease has proven the most effective form of treatment , actually regaining functions and neurons.
- Dopamine neurons derived from human ES cells efficiently engraft in animal models of Parkinson’s disease.
From a more digestible version.
US researchers say they have overcome previous difficulties in coaxing human embryonic stem cells to become the neurons killed by the disease. Tests showed the cells survive and function normally in animals and reverse movement problems caused by Parkinson's in monkeys.
- Stem cells transformed into brain cells to treat Parkinson's disease - The Guardian