Cellular Biology

Cloned Beef

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This month (May 2008), the FDA approved the cloned beef for human consumption. The technology, developed by companies such as Viagen (Australia) and SEK genetics (USA) was developed in 2003 and has been used for breeding show animals. Although there was a voluntary moratorium on the slaughter of cloned cows for consumption while the FDA completed its review, there have been reports of the open sale of semen from cloned animals to breed feed animals despite the moratorium. Thus, industry insiders have stated that some cloned meat has very likely already found its way to the meat counter, although it represents a very small percentage of the overall supply. They contend that since no reports of illness were received, the meat is safe.

Cloning involves the transfer of the genome from differentiated adult' cells into embyronic cells. Epigenetics is a newly emerging field that studies chemical modifications that affect gene function without changing the gene sequence. Typically, these changes accumulate during developmental programming and the inter-related effects of the environment, stress, and aging on the genome. Many, but perhaps not all, of these changes are undone' during the production of gametes (sperm and egg) by meiosis.

Cloning bypasses the normal mechanism of meiosis, resulting in inefficient conversion of genome into the unprogrammed' state. This can cause developmental abnormalities in the animals produced by cloning. In some cases, up to 90% of the embryos generated by cloning are discarded immediately due to obvious growth problems. Japanese scientists found that even healthy cloned mice show significant abnormalities in gene expression, with up to 13% of the genome affected.

While you can argue that we are not necessarily interested in the overall health of the cow we are going to consume, only the quality of the meat itself, this does present serious ethical issues. Critics contend that the FDA has analyzed only a few short-term studies, some by industry scientists with clear conflicts of interest. The FDA has been accused of using the five-year moratorium to simply wait out public rejection, rather than conduct new, comprehensive safety or ethics studies. It is thought that the FDA and USDA learned from missteps in the introduction of genetically modified foods a decade ago; initial public outcry soon fades to acceptance.

The fact is, very few scientists are willing or able to conduct the studies necessary to fully satisfy critics of agricultural biotechnology. Those that have done so face severe criticism from colleagues, lobbyists, industry scientists, and funding agencies that brand them "anti-technologists". This is a serious concern to the public, who expect science to be objective and comprehensive, especially in areas of human health.

Another concern is the paucity of monitoring in the US. Since most Americans are completed divested from the source of the food they buy in the supermarket, it is doubtful that the appearance of cloned beef will cause a loss of consumer confidence. Surveys by the Pew Trust show that most shoppers would avoid cloned meat if they could, most do not read labels and expend little thought on food origins. European agencies use DNA tracking technology to regulate cloned and genetically modified foods. American food lobbies have been very successful at avoiding tracking and labeling requirements. Disturbingly, watchdog groups and not federal agencies have detected contamination of the food supply with genetically modified organisms.

Most scientists acknowledge the many benefits of advancing agricultural technology in the face of population growth, rising standards of living in second- and third-world nations, and climate change. However, there is an extensive historical record of safety concerns that were swept aside in favor of agricultural advance. Although they could be perfectly safe, the fact is that the long-term effects of cloned and modified foods have not been studied and may only be clear after wide-scale consumption of such products by the public.

More about this author: Heather Youngs

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