Scott Walker says scientists agree that adult stem cell research holds more promise than embryonic

Stem cell research has emerged as a bright line separating the 2010 candidates for governor in Wisconsin.

Democrat Tom Barrett supports both adult and embryonic stem cell research and sought to portray Republican rival Scott Walker as extreme with a TV ad that claimed Walker wants to ban stem cell research.

We rated that claim False, since it made no distinction between adult stem cell research, which Walker supports, and embryonic stem cell research, which he opposes.

In the wake of the ad, Walker refused to say whether he supports an outright ban on embryonic stem cell research, though he told a pro-life group in the spring he would sign such a bill. In explaining his views at an Oct. 12, 2010 news conference, Walker made this  pronouncement about stem cell research:

"Scientists have shown us (that) the greater possibilities, the real science movement, has been with adult stem cell research. It has not been with embryonic," Walker said.

He then added for emphasis: "That’s not a political statement; that’s a statement of scientific fact out there."

We went to the lab -- and several experts on stem cell research -- to see if Walker’s claim on the merits of both sorts of research is true.

First, we’ll note two things: 1) There is great hope that stem cell research, which has been used to treat some blood diseases and cancers, may one day treat and cure many diseases. 2) Adult stem cell research is older and generally not controversial, while embryonic is newer and controversial because it involves the destruction of a human embryo.  

In this item, we are not trying to settle the debate over what is morally right or ethically responsible. We are strictly looking at Walker’s statement.

Asked to support Walker’s claim that adult stem cell research is considered by scientists to be superior to embryonic, his campaign cited statements by a federal agency -- the National Institutes of Health -- that differentiate the two:

• Adult stem cells "are currently the only type of stem cell commonly used to treat human diseases." Doctors have been transferring them in bone marrow transplants for over 40 years.

• Embryonic stem cells "are thought to offer potential cures and therapies for many devastating diseases, (but) research using them is still in its early stages." Experiments with them didn’t begin until 1998.

Walker quotes the National Institutes of Health accurately -- but selectively.

The NIH also says adult and embryonic stem cells each have advantages and disadvantages -- and that there is a major difference between them: Embryonic stem cells can become all cell types of the body, while adult stem cells "are thought to be limited to differentiating into different cell types of their tissue of origin."

Momentum for embryonic stem cell research connected with the National Institutes of Health grew with an executive order issued by President Barack Obama in March 2009. It lifted restrictions on the work that had been imposed by President George W. Bush.

Obama’s order said in part: "Advances over the past decade in this promising scientific field have been encouraging, leading to broad agreement in the scientific community that the research should be supported by federal funds."

The future of federally funded embryonic stem cell work has been uncertain since a judge in August 2010 blocked Obama’s order; that ruling is being appealed. But experts we consulted said, as Obama’s order did, that there is broad agreement among scientists about the potential of embryonic stem cell research.

International Society for Stem Cell Research: Lawrence Goldstein, a member of the society’s board and director of the stem cell program at the University of California, San Diego, told PolitiFact Wisconsin "there is no scientific basis" for Walker’s statement.

"While adult stem cells show promise in some therapeutic settings, there are many therapeutic needs that adult stem cells do not appear likely to meet," said Goldstein, who has testified before Congress on National Institutes of Health funding and stem cell research. "In particular, for neurodegenerative diseases such as (Lou Gehrig’s disease) and other related disorders, embryonic stem cells and related stem cell types show great promise both for therapy and for teaching us what is going wrong in these disorders so that we may develop better therapies in the future.   

"Thus, based on scientific considerations and data, it is far too early to conclude that one stem cell type or another will solve all the medical problems we seek to solve, so research with all types must proceed so that we can find out what is best for each type of disease."

National Academies of Science: In September 2008, the academies noted developments in efforts to reprogram adult stem cells to an embryonic stem cell-like state. But "it is far from clear at this point which cell types will prove to be the most useful for regenerative medicine," the academies said, "and it is likely that each will have some utility."

Earlier this year, the academies again said it is important to not cut off some areas of stem cell research.

Medical College of Wisconsin: Stephen Duncan, director of the college’s stem cell biology program, said no one knows whether embryonic or adult stem cells hold the most promise because research is ongoing. "We just can’t answer whether embryonic or adult stem cells are the best," he said. "The tests haven’t been done."

We’ve done enough research, however, to draw a conclusion about Walker’s claim.

In supporting his views, Walker said scientists agree the most promising research is focused on adult stem cells, not embryonic stem cells. In supporting that claim, he selectively cites part of a statement by the National Institutes of Health. A broader look at the evidence shows the consensus among scientists is that embryonic stem cells hold great promise in treating diseases, in some ways may be superior to adult stem cells and are deserving of more research.

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Ron Johnson

stated on September 28, 2010 in a campaign TV ad

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We rate Walker’s claim False.