Animal-model experimentation is not predictive of effects in humans. Therefore, it is not just useless torment of animals, it is misleading and dangerous when the results are relied upon. In a couple of articles whose URLs I can't find at the moment, the Physicians Committee for Responsible Medicine provides some specific information on the issue:
Let’s take an example from the pharmaceutical world. Currently drugs have over a 90% failure rate, which means they are certified safe from animal studies, then fail in human clinical trials or once they reach the market. This crisis has led the FDA, NIH, and DARPA to spend tens of millions of dollars on “human-on-a-chip” research projects, a promising nonanimal testing method.
Broadly, there are significant genetic, molecular, and metabolic differences between humans and animals used for testing. In toxicity tests, often different sexes or strains of the same species react differently to chemicals.
This makes it impossible to accurately predict potential effects of chemicals on humans -- especially given the diversity of our population. Age, developmental stage, disease state, diet -- all of these factors affect how a person would respond to a chemical. Animal tests can’t cover all that diversity.
Additionally, animals are often exposed to doses of chemicals thousands of times higher than humans would ever be exposed to, sometimes leading to dubious results or repeated testing. The cramped, stressful conditions in which animals are kept -- as well as their individual, unique reactions to their environment -- make animal tests extremely unreliable.
Research on tobacco risks provided some of the strongest evidence that animal experiments can be dangerous and misleading, showing that there is no substitute for human data in searching for the causes of human disease. In the early 1960s, the tobacco lobby used all the political and scientific clout it could muster against health warnings about smoking. One piece of evidence helped their case: animal experiments did not show that inhaled smoke causes cancer. In study after study, animals forced to inhale smoke did not get cancer. As Clarence C. Little wrote in the New England Journal of Medicine, June 15, 1961, “There have been many such experiments here and abroad, and none have been able to produce carcinoma of the lung in animals.” Dr. Little worked for the Tobacco Research Committee and for Jackson Laboratory, a large-scale animal breeder. He used the results of animal experiments to argue that lung cancer is not linked to smoking tobacco. Rather, he claimed that lung cancer “is a challenge, an unsolved problem. Its etiology will probably long be an open question.” While Little’s conclusion served both of his employers, it was no help to human health. Indeed, in another editorial published at about the same time, Dr. Donald B. Effler of the Cleveland Clinic argued that animal experiments offered little support for the smoking-cancer link, and that a smoker who does not yet have a chronic cough “assumes little risk to his health.”[1] The animal experiments were clearly doing more harm than good, delaying warnings about smoking.
Of course, the key evidence on tobacco came from human studies. Whether one looks at large human populations or at individual smokers, the link between tobacco smoke and cancer is inescapable, even though it was completely missed in animal inhalation experiments. So the question is, have animal experiments led us astray in other areas?
Inaccurate Results
Nutrition is another area where animal experiments have raised repeated problems. While it is easy to feed vitamins, fat, or fiber to animals and to check whether their disease rates rise or fall, the relevance to humans is limited at best, due to major physiological differences between species. For example, if vitamin C helps prevent cancer, what is the impact on cancer research of the fact that rats and mice synthesize vitamin C within their bodies, unlike humans, who do not? Likewise, rats differ from humans in crucial enzyme functions. For example, rats have much higher activity of the 5-desaturase enzyme system, a part of the body’s machinery for processing fats in the diet. Because of this species difference, rats are “not an appropriate human model” for studying the effects of fats.[2]
Although rats have been used extensively to test the value of various iron supplements, it turns out that rats absorb iron quite differently from humans and do not give usable information. According to a report in the American Journal of Clinical Nutrition, “Our studies indicate that rodents cannot be used to assess the quantitative importance of dietary factors in human iron nutrition.”[3]
Research on stroke provides another example. For years, experimenters have used animal experiments to create brain damage that simulates the effects of a human stroke. They then test out various experimental drugs to see whether they reduce the damage to the brain. But a review in the journal Stroke, published by the American Heart Association in January 1990, reported that, of 25 different treatments that worked in rodents, not a single one worked in human patients. As the Stroke editorial lamented, such animal experiments were not only failing to advance science, they were actually impeding progress:
“Each time one of these potential treatments is observed to be effective based upon animal research, it propagates numerous further animal and human studies consuming enormous amounts of time and effort to prove that the observation has little or no relevance to human disease or that it may have been an artifact of the animal model itself.”[4]
Are animal experiments that lead researchers astray simply rare exceptions or are they typical of animal tests? Broader data come from a U.S. General Accounting Office review of the safety of all new drugs marketed in the decade 1976 to 1985. All had been animal-tested prior to approval. Of the 198 new drugs for which data were available, 102 (51.5 percent) were more dangerous than pre-market animal tests and limited human tests had indicated, so much so that they had to be relabeled or withdrawn.[5]
http://www.pcrm.org/research/health...mpendium/an-examination-of-animal-experiments
Animal-model experimentation invariably causes distress, often including severe pain, for the animals. This, in and of itself, confounds results that aren't predictive anyway.
Among the alternatives to unscientific animal-model experimentation are:
In vitro cell culture
“Organoids”
“Organs-on-chips”
“Human-on-a-Chip”
Computer simulation
Autopsy studies and study of postmortem specimens
Epidemiological studies
Noninvasive imaging
Microdosing
Alternatives to Animal Research | National Anti-Vivisection Society
