The controversy over the human consumption of meat and dairy products from cloned cows continues. The UK Advisory Committee on Novel Foods and Processes, after reviewing the evidence, concluded that there was no substantial difference between meat and dairy from cloned cows compared to conventional cows. However, food products from cloned animals and their offspring remain banned in Europe.

Use of offspring of cloned cows, sheep and pigs are legal in the US, South America, and Asia. Australia is likely to follow suit in a year or two. The European Union (EU) has an effective ban at the moment, but the policy is under review. The UK is also negotiating with the EU regarding the use of clones.

There is not much of a theoretical reason to suspect that cloned animals would present a health risk. The primary concern is that something unanticipated might have occurred during the cloning process, causing the animal to be genetically or developmentally abnormal. However, if the cloning process works properly this should not happen. Further, if mutations do occur, but the animal lives, it is likely that any changes do not represent a risk to humans who consume the meat or dairy from such clones.

It is even more unlikely that the offspring of a cloned animal would present a health risk – for then whatever mutation or abnormality resulted from a flawed cloning procedure would have to be passed on to offspring.

It is therefore no surprise that there is no evidence for any harm or risk from cloned animals or their offspring. In fact cloned animals appear to be identical to normally bred animals. We once again are faced with the situation of little theoretical risk, with no direct evidence of risk, but with a new technology and therefore unknowns. Where does the precautionary principle lie? It is always possible to demand greater testing and evidence of safety. It seems more prudent to deal with relative risks. In this case the relative risk appears to be quite small, and there are potential benefits to food production.

The EU is at the cautious end of the spectrum when it comes to new methods of food production. For example, they continue to be extremely negative with respect to genetically modified (GM) food. Since GM involves altering genes or introducing new genes, there is legitimate concern for safety and a greater burden of proof of safety. Cloned animals do not, or should not, have altered genetics.

The trend seems to be in favor of accepting cloned animals into the human food chain. This is reasonable given the lack of evidence for any risk and the low plausibility that there should be any.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.