By Dr. Alka Chandna
Experiments on animals have long been criticized for their cruelty as well as for their failure to produce results that apply to humans.
The U.S. Food and Drug Administration reports that nine out of 10 drugs that test safe and effective in animals are found to be either unsafe or ineffective in humans.
Drugs that effectively treat artificially induced cancers in mice and strokes in monkeys, for example, don’t work in humans. Part of the reason for this failure is that all animals are different – genetically, anatomically, metabolically and so on – and results obtained from tests on other animals simply can’t be reliably applied to us.
Now, compounding these fundamental problems, several new comprehensive studies show that experiments on animals are typically designed, conducted and reported in such a sloppy and biased way that they exaggerate results, downplay negative findings and can’t even be reproduced.
A recent survey conducted by an international team of scientists analyzed thousands of published animal studies of pharmaceutical drugs and found that the overwhelming majority of these studies were poorly designed and did not even take elementary steps to prevent skewed results. Experimenters failed to assign animals to treatment groups in a randomized fashion in order to ensure, for instance, that the healthiest animals weren’t all being assigned to the group receiving the treatment being tested.
They also failed to ensure blinded assessment of the results, which is necessary in order to prevent the experimenters’ expectations of the outcome from influencing their judgment of the actual outcome, and they failed to ensure that the numbers of animals used would produce meaningful results. These measures are fundamental to valid research, but when it comes to studies using animals, experimenters seem not to know the basics or care about them—or both.
In another recent study, scientists at McGill University analyzed hundreds of animal experiments carried out with a particular kidney cancer drug and found that data suggesting the drug had little to no effect in combating cancer were not published. Consequently, published studies overestimated the effectiveness of the drug by up to 45 percent.
The lead author of this study commented, “Preclinical [animal] research is plagued by poor design and reporting practices, exposing patients to harmful and inactive agents, wasting time in the lab and driving up the price of drugs.”
These latest surveys follow a succession of similar reports of flawed experimental design and conduct and publication bias. Add to this the fact that dozens of studies have demonstrated that seemingly insignificant differences in the ways in which animals are housed and treated in laboratories—including lighting, caging, noise, smells and diet—can further confound results in ways that experimenters don’t recognize and often can’t control.
A 2014 article in The BMJ coauthored by a Yale School of Medicine physician-scientist examined these and other problems and concluded, “If animal researchers continue to fail to conduct rigorous studies and synthesise and report them accurately, and if research conducted on animals continues to be unable to reasonably predict what can be expected in humans, the public’s continuing endorsement and funding of preclinical animal research seems misplaced.”
Yet the National Institutes of Health continues to dedicate nearly half of its $30 billion annual budget of tax dollars to projects that involve inherently flawed and methodologically questionable experiments on animals, including tearing infant monkeys away from their mothers at birth in order to cause depression, injecting hamsters with steroids and forcing them to fight, addicting rats to cocaine and forcing dogs to run on treadmills until they have heart attacks.
Far from producing good science, these experiments cost millions of animals their lives, waste limited resources, misinform the scientific community and give false hope to the public. By switching to cutting-edge and superior human-based research tools such as organs-on-chips, we can safeguard funding, advance human health and save animals.