Animals are not the same as humans, so foods and medicines that affect them in one way may well affect us differently.

Protease inhibitors are substances that retard the action of digestive enzymes that cause the breakdown of protein. Studies that show that protease inhibitors can cause cancer in some animal species, but there is almost no evidence even suggesting that they have the same effect in humans. In fact, protease inhibitors appear to reduce the incidence of colon, prostate and breast cancer in humans.

A 1985 study showed that soy increases the risk of pancreatic cancer in rats. But researchers with the National Cancer Institute point out that the pancreas of a few species of animals, notably rats and chicks, are extraordinarily sensitive to dietary protease inhibitors such as those found in soy. This sensitivity has not been found in other species such as hamsters, mice, dogs, pigs, and monkeys, they say, and is “not expected to occur in humans.” In fact, while rats fed nothing but soy run higher risks of pancreatic cancer, human populations consuming high levels of soy have decreased rates of pancreatic cancer.

Species, even those that seem quite closely related, often function quite differently at a molecular level. It is true that baby rats fail to thrive on soy. But they also fail to thrive on human breast milk. This is because rats and humans have vastly different requirements. Human milk, for example, is 5% protein; rats’ milk is 45% protein. The difference in nutritional requirements and responses for different species can be enormous. Foods that are highly nutritious for one species are often inedible or even poisonous to other species.

The drug Thalidomide caused horrendous birth defects in children born to mothers who took the drug during their pregnancies. Thalidomide had been widely tested on animals, where it appeared to be totally safe. Similarly, the combination of fenfluramine and dexfenfluramine, recently touted to be the answer to dieters’ prayers, was extensively tested on animals and found to be very safe. Unfortunately it caused heart value abnormalities in humans. When the arthritis drug Opren was tested on monkeys, no problems were found, but it killed 61 people before it was withdrawn. Cylert was fine for animals, but when it was given to hyperactive children it caused liver failure. In studies of weight-loss drugs, rats have lost as much as 30 percent of their weight, but humans on the same drug have lost less than 5 percent of their weight.

Even higher than the number of people who die from medication errors is the number of people who die from medication, period. Even when a prescription drug is dispensed properly, there's no guarantee it won't end up killing you.

A remarkable study in the Journal of the American Medical Association revealed that prescription drugs kill around 106,000 people in the US every year, which ranks prescription drugs as the fourth leading cause of death. Furthermore, each years sees 2,216,000 serious adverse drug reactions (defined as "those that required hospitalization, were permanently disabling, or resulted in death").

The authors of this 1998 study performed a meta-analysis on 39 previous studies covering 32 years. They factored out such things as medication errors, abuse of prescription drugs, and adverse reactions not considered serious. Plus, the study involved only people who had either been hospitalized due to drug reactions or who experienced reactions while in the hospital. People who died immediately (and, thus, never went to the hospital) and those whose deaths weren't realized to be due to prescription drugs were not included, so the true figure is probably higher.

Four years later, another study in the JAMA warned:

Patient exposure to new drugs with unknown toxic effects may be extensive. Nearly 20 million patients in the United States took at least 1 of the 5 drugs withdrawn from the market between September 1997 and September 1998. Three of these 5 drugs were new, having been on the market for less than 2 years. Seven drugs approved since 1993 and subsequently withdrawn from the market have been reported as possibly contributing to 1002 deaths.

Examining warnings added to drug labels through the years, the study's authors found that of the new chemical entities approved from 1975 to 1999, 10 percent "acquired a new black box warning or were withdrawn from the market" by 2000. The "probability of a new drug acquiring black box warnings or being withdrawn from the market over 25 years was 20%."

In 1997, 39 new drugs were approved by the FDA. As of now [May 2002], five of them (Rezulin, Posicor, Duract, Raxar and Baycol) have been taken off the market and an additional two (Trovan, an antibiotic and Orgaran, an anticoagulant) have had new box warnings. Thus, seven drugs approved that year (18% of the 39 drugs approved) have already been withdrawn or had a black box warning in just four years after approval. Based on our study, 20% of drugs will be withdrawn or have a black box warning within 25 years of coming on the market. The drugs approved in 1997 have already almost "achieved" this in only four years — with 21 years to go.

The cruel experimenter cannot be allowed to have it both ways. He cannot, in the same breath, defend the scientific validity of vivisection on the grounds of the physical similarities between man and the other animals, and then defend the morality of vivisection on the grounds that men and animals are physically different. The only logical alternatives for him are to admit he is either pre-Darwinian or immoral. - Richard D. Ryder, English scientist, Author

Ask the experimenters why they experiment on animals, and the answer is: “Because the animals are like us.” Ask the experimenters why it is morally OK to experiment on animals, and the answer is: “Because the animals are not like us.” Animal experimentation rests on a logical contradiction. - Dr. Charles R. Magel, Prof. of Ethics, Moorhead St. Univ.

Vivisection is anti-science and anti-health, and is leading us down a path of waste and decay! I encourage people to fight the dangerous dead-end of animal experimentation. - Murray Cohen, MD, Founding co-chair of the Medical Research Modernization Committee.

When evaluated on the basis of real usefulness to humanity, "scientific research on Animals" is a fraud, whether intentional or not. - William A. Cave, Late President of AAVS

It took me a couple of years reading the vivisectors' own literature to convince me that animal experiments have no scientific relevance to human health anyway. - Chris DeRose, founder, Last Chance for Animals

Results from animal tests are not transferable between species, and therefore cannot guarantee product safety for humans...In reality these tests do not provide protection for consumers from unsafe products, but rather they are used to protect corporations from legal liability. - Herbert Gundersheimer, M.D., Baltimore 1988

Animal studies are done for legal reasons and not for scientific reasons. The predictive value of such studies for men is meaningless. - Dr. James D. Gallagher, Journal of the AMA 3/14/1964

During the last 80+ years, scientists experimenting on trillions of animals, came up with 900 ways of causing cancer in a mouse...BUT NO CURE TO HUMANS! - J. F. Brailsford, MD

We have cured mice of cancer for decades - and it simply didn't work in humans. - Dr. Richard Klausner, of the National Institute of Cancer

What good does it do you to test something (a vaccine) in a monkey? You find five or six years from now that it works in the monkey, and then you test it in humans and you realize that humans behave totally differently from monkeys, so you’ve wasted five years. - Dr. Mark Feinberg, a leading AIDS researcher

Giving cancer to laboratory animals has not and will not help us to understand the disease or to treat those persons suffering from it. - Sabin Albert, MD, A physician and microbiologist. Developed a live-virus polio vaccine that helped curb the spread of the then deadly disease.

About 40 per cent of all procedures used some form of anaesthesia to alleviate the severity of the interventions. For many of the remaining procedures the use of anaesthesia would have increased the animal welfare cost of the procedure. - Coalition for medical progress website – 4.2.06, www.medicalprogress.org

...many vivisectors still claim that what they do helps save human lives. They are Lying. The truth is that animal experiments kill people, and animal researchers are responsible for the deaths of thousands of men, women and children every year. - Dr. Vernon Coleman, English doctor

There are only two categories of doctors and scientists who are not opposed to vivisection: Those who don’t know enough about it and those who make money from it. - Werner Hartinger, Chief Surgeon, W. Germany, 1988

You are not handling a lump of plastic. You are handling animals with central nervous systems that feel pain and suffering. - Janice Swanson, Animal behavior specialist at Kansas State University

At present it is a rare person that emerges from medical training with his or her humanity intact. - Journal of the American Medical Association, Vol 261, p. 2011

Doctors who speak out in favour of vivisection do not deserve any recognition in society, all the more so since their brutality is apparent not only during such experiments, but also in their practical medical lives. They are mostly men who stop at nothing in order to satisfy their ruthless and unfeeling lust for honours and gain. - Hugo Knecht, Ear, Nose, Throat Specialist, Linz, October 5, 1909

I do not believe that any of the suffering I have caused to laboratory animals has helped humanity in the slightest. - Richard D. Ryder, English scientist, Author

It (referring to dog labs) did more to damage my identity as a physician than anything else. I learned nothing physiological. I learned that life is cheap, and that misery can be ignored. - Murray Cohen, MD, Founding co-chair of the Medical Research Modernization Committee.

It is totally unconscionable to subject defenseless animals to mutilation and death, just so a company can be the first to market a new shade of nail polish, or a new improved laundry detergent. - Abigail "Dear Abby" Van Buren, A well-known syndicated advice columnist and author, Testifying before Congress, 1988

Vivisection has done little for the art of the doctor at the bedside, but it has done immeasurable harm to the character and mind of the rising generation of doctors. - Dr. Rudolph Hammer, LLD

Vivisection is barbaric, useless, and a hindrance to scientific progress. - Werner Hartinger, Chief Surgeon, W. Germany, 1988

We sacrificed daily from one to three dogs, besides rabbits and other animals, and after four years experience, I am of the opinion that not one of these experiments on animals was justified or necessary. - Dr. George Hogan, student of Claude Bernard, France

What are we doing when we brainwash children in schools to cut open their fellow animals? Are we dangerously desensitizing them? Some of the most warped and blunted people I know are those who have gone through training of this sorts. - Richard D. Ryder, English scientist, Author

There will come a time when the world will look back to modern vivisection in the name of Science, as they do now to burning at the stake in the name of religion. - Dr. Henry J. Bigelow, Boston surgeon, pioneer in use of ether

I had bought two male chimps from a primate colony in Holland. They lived next to each other in separate cages for several months before I used one as a (heart) donor. When we put him to sleep in his cage in preparation for the operation, he chattered and cried incessantly. We attached no significance to this, but it must have made a great impression on his companion, for when we removed the body to the operating room, the other chimp wept bitterly and was inconsolable for days. The incident made a deep impression on me. I vowed never again to experiment with such sensitive creatures. - Dr. Christian Barnard, Performed first open heart transplant

During my medical education at the University of Basel I found vivisection horrible, barbarous, and above all unnecessary. - Carl G. Jung, Swiss psychologist. The founder of analytical psychology. His break with Freud is an important event in the history of psychoanalytic thought.

I abhor vivisection. It should at least be curbed. Better, it should be abolished. I know of no achievement through vivisection, no scientific discovery, that could not have been obtained without such barbarism and cruelty. The whole thing is evil. - Dr. Charles W. Mayo, son of co-founder of the Mayo Clinic, a skilled surgeon and a member of the Mayo Clinic’s Board of Governors

• Bad Medicine, the 2007 breakthrough film that puts forward the most basic scientific and medical arguments against vivisection.

• Frequently Asked Questions
• Alternatives To Animal Testing
• Inside the FDA
• Heart Failure - Diary of a Third Year Medical Student
• Three U.S. Agencies Aim To End Testing On Animals