My concern with using animals in research primarily revolves around using them as predictive models for human response to drugs and disease. AIDS vaccines have succeeded in monkeys but harmed humans. Countless drugs that have helped humans would have been lost had animal studies been believed. Animal models are simply not predictive for human response. The sensitivity, specificity, negative and positive predictive values for touting animal models as predictive is simply inadequate. (See Animal Models in Light of Evolutionfor an in depth analysis of the prediction issue).
Despite my preference to stick with the science, the question I am most often asked is “Why does such use continue?” This lies outside my comfort zone. However, as this is so frequently asked, I usually attempt to shed some light, based on my experiences and an analysis of similar situations. My explanation infuriates those with a vested interest in using animals as I almost always point out the money connection. But another reason such use persists is, to paraphrase Edmund Burke: all that is needed for nonsense to continue is for skeptics to do nothing. In this blog, I ask skeptics to consider the following three examples.
1. Recently, Dr Dario Ringach said in a blog:
Now think... ask yourself: in what version of evolutionary biology can one expect studies with flowers to save lives, while studies with animals be guaranteed to fail? (Hint: None.)
This is classic fallacious reasoning, as I know of no scientist who has said that studies with animals are guaranteed to fail. Animals cannot predict human response but they can be used for many other scientific endeavors, as I have repeatedly said. Dr Ringach is again setting up a straw man. Fallacies like this are the bread and butter of vested interest groups in general, thus Dr Ringach’s statement does not surprise me. What I would like to know however is where are all the skeptics and critical thinkers who would, were the subject matter different, be all over such fallacious reasoning? Even a superficial reading of Dr Ringach’s blogs will reveal numerous fallacies. Where is the outcry from skeptics? The use of animals as predictive models in research has more far reaching ramifications than homeopathy, which is routinely (and rightly) attacked by skeptics.
2. Outspoken supporter of using animals in research Dr David Gorski wrote in his blog on May 10, 2010:
Another good part of the report [from the President’s Cancer Panel] is its emphasis on the deficiencies in our current technology and tools for assessing the carcinogenic potential of various chemicals. Related to the report’s emphasis on how little we know about carcinogenesis in children, the report criticizes current animal models because they fail to capture the impacts of early exposures and miss the late effects of such exposures. Also problematic is that most animal studies use long-term, high-dose exposures that may have little relation to humans. Consequently, the report urges the development of alternatives to animal testing involving testing in human cells in vitro. I’m rather skeptical that this recommendation will produce much benefit very fast. After all, one reason we use animals is because, as imperfect as animal carcinogenesis studies are, the correlation between cell culture studies is even more unreliable than that of animal studies. (1) (Emphasis added.)
His statement seems to be at odds with the following from Salen in 1994 in the Handbook of Laboratory Science Volume II:
The case of the huge 25-year screening program, undertaken by the prestigious U.S. National Cancer Institute, illustrates the kinds of dilemma possible: in this program 40,000 plant species were tested for anti-tumor activity. Several of the plants proved effective and safe enough in the chosen animal model to justify clinical trials in humans. In the end, none of these drugs was found useful for therapy because of too high toxicity or ineffectivity in humans. This means despite 25 years of intensive research and positive results in animal models, not a single antitumor drug emerged from this work. As a consequence, the NCI now uses human cancer cell lines for the screening of cytotoxics. (2)
I asked Gorski to provide references for this position on May 11 but he has not replied.
The website where Gorski posts is called Science-Based Medicine and I highly recommend it! It is a very good source for learning about what does and what does not work in medicine. But the strengths of the website are that it is science-based, adheres to the rules of the scientific method and scientific evaluations including citing references, and does not allow unsubstantiated nonsense. Maybe Gorski has substantiation for his comment but he has not provided it. Sadly, this lack of response is common when asking questions of the vested interest groups, including the animal-based research community. Maybe Gorski is on vacation or otherwise unavailable. If so, I look forward to hearing from him when he is available. (For the record, Gorski declined my previous invitation to discuss the use of animals as predictive models in an indexed peer reviewed science journal that was seeking a Point Counter Point-style debate. For more on statements by Dr Gorski see Response to Orac.)
3. Scientists who are not animal-based researchers themselves but who are in universities that are dependent upon money from animal-based research uncritically support animal-based researchers. For example, The Oxford Student (the student paper at Oxford) published an article by Rachel Bennett about Dr Macleod and animal-based researcher Dr Tipu Aziz:
Malcolm Macleod, a clinical neuroscientist, was asked by Animal Aid to conduct a systemic review into Aziz’s research. Macleod accidentally sent an email intended for a colleague to animal rights group Animal Aid. The e-mail stated he felt that Deep Brain Stimulation [the area of Aziz’s research] was an “area of weakness often trumpeted as a success, but which in reality is probably a failure”. He asked for “advice” and suggested he would "avoid, play a straight bat or price [himself] out of the market” for the review requested. Animal Aid said about the e-mail “He [Dr Macleod] feared that an objective investigation of the associated animal research would expose the treatment's shortcomings. He was determined to avoid being drawn into the front line of the vivisection debate.” Dr Macleod claimed that he stood by his choice not to do the review “I was not comfortable taking part in a study which was motivated by a desire to undermine Aziz.” (My additions are in bold.)
The skeptic community has contributed and is contributing greatly to debunking nonsense. But with the exception of Skeptic magazine (see 2007;13(3):44-51) the community has been very silent or even hostile (see transcript and video of debate with Andrew Skolnick) on this issue. Why are they allowing to go unchallenged the position that animals can be used as predictive models for humans? If animal models are not predictive, then the FDA and EPA should vastly change their rules and regulations. (NIH would also need to change some of their funding assumptions but the FDA and EPA would have to more or less start over.)
I will accept from any organization that stands for critical thought and science any invitation to engage in public dialogue on this issue.
(For more on fallacious reasoning and animal models, please read FAQs About the Use of Animals in Science: A handbook for the scientifically perplexed.)
1. D. Gorski. (Science-Based Medicine, 2010), vol. 2010. http://www.sciencebasedmedicine.org/?p=5045#more-5045.
2. J. C. W. Salén, in Handbook of Laboratory Science Volume II. Animal Models. 1st edition., P. Svendsen, J. Hau, Eds. (CRC Press, Boca Raton, 1994), pp. 1-6.