Friday, December 29, 2006

Franken-furters?

I am a bit skeptical of the nascent approval of the use of cloned animals for meat and dairy products. There is an interesting article in the most recent issue of First Things by neurobiologist Maureen Condic. Dr. Condic points out that cloned animals (few of which survive to birth) are almost always genetically abnormal with "multiple genes aberrantly expressed in multiple tissues."


As Dr. Condic points out, this presents huge problems for the posited use of somatic cell nuclear transfer to create cloned human embryos that can then be used to derive stem cells, tissue and perhaps even organs to treat disease. Even if we someday figure out how to clone a human embryo and even if some will turn out normal enough for therapeutic use, how do we tell which ones? She writes "[h]ow normal is this particular cloned embryo, the one we are going to use to generate stem cells to treat this particular patient?"

Given the problems with immune rejection in stem cell based therapies, this is a tsunami of cold water for those who believe that embryonic stem cell research will end disease as we know it, but I wonder if it is not pertinent on the question of cloned meat and dairy products.

The FDA study group seems to acknowledge the high rate of abnormality, but concludes that all should be well as long as "obviously sick and deformed animals were kept out of the food supply ..." It says that clones that survive past the first few days "appear to grow and develop normally" and that healthy adult clones are "virtually indistinguishable" from non-cloned livestock.

Is this right? Are cows that "appear" normal really normal enough to eat? Given the relatively few cloned animals (maybe several hundred in the US) and the fact that they have been kept out of the food supply, how can we know?

I prefer market solutions and I am generally uncomfortable with the hysteria over genetically modified foods, but this seems to present enough of an uncertainty that a labeling requirement might be in order.

1 comment:

Anonymous said...

"Given the problems with immune rejection in stem cell based therapies, this is a tsunami of cold water for those who believe that embryonic stem cell research will end disease as we know it, but I wonder if it is not pertinent on the question of cloned meat and dairy products."

Methinks thou doth protest too much. You folks are so anxious to dump cold water on embryonic stem cell research that you will grasp at any straw. Perhaps you ought to listen to Jamie Thomson, who has been telling everyone who will listen that this isn't where embryonic stem cell research is likely to have its greatest immediate impact.

Take a look at the company he has created which will "grow" heart cells in order to test new phamaceuticals. Right now, it isn't possible to determine in advance what impact a new drug will have on the heart. His company will develop heart stem cells for drug testing purposes.

Think of all the medications that have been pulled from the market in recent years because they have caused heart damage after release. His new company should be able to eliminate those risks during the drug approval process.

Sit back and let the scientific research take place.