By Neal Barnard, M.D., Physicians Committee for Responsible Medicine (PCRM)
A trend away from animal testing methods is beginning, which will help not only the animals but people, too, particularly in the area of cancer research. In order to determine whether or not chemicals may cause cancer, the Environmental Protection Agency (EPA) still uses animal tests. Obviously, these tests are not very kind to the animals involved, who are kept in cages for years, fed doses of chemicals, and subjected to frequent examinations. These tests are cruel to people, as well, because they take so long to complete that they actually guarantee continued human exposures to dangerous carcinogens for years.
Let’s say, for example, that you suspect a chemical in use near your home causes cancer. The EPA begins animal tests, yet years will go by before you hear anything about it. And the EPA will not have the chemical removed until the tests are finished. Why? Because to do so might injure the businesses that produce or use the chemical in question.
Now, if the EPA were to use non animal tests, such as the Ames test (which uses salmonella bacteria to identify carcinogens), the chemical could be indicted within a week. Moreover, since the short-term, non animal tests are relatively inexpensive (approximately one percent of the cost of animal tests), it is possible to complete far more tests than is possible using animal subjects.
Not only are non-animal methods cutting a new path in the testing of cancer-causing chemicals, they are also revolutionizing the search for cancer cures. For years, scientists have used massive numbers of mice, about a million per year, to screen potential anti-cancer drugs. Mice with leukemia, a cancer of the blood cells, are given various substances to see if there is any effect on the cancerous cells. If so, the substance may find its way into human trials. But this system has a phenomenally low yield. Investigators at the National Cancer Institute (NCI) became concerned that the reason for the general failure of the system is that mice and humans have very different kinds of cancer—and very different ways of reacting to it physiologically.
A new method uses cultures of human cancer cells. These cells are obtained from biopsies or surgeries. In an automated method developed by Robert Shoemaker and Michael Boyd of the NCI, colon cancer cells, breast cancer cells, and many other cell types can be kept alive in test tubes. Substances are applied to these cells, and the results are checked and entered into a computer. Using this method, tens of thousands of potential anti-cancer drugs can be screened. Ironically, this high-tech approach relies on consultations with tribal healers from Latin America to identify plant extracts and other medicines to be tested.
Just as shifting away from animal tests helps in the technology of cancer research, shifting animal products out of our diet helps in cancer prevention. A vegetarian male lives an average of six years longer than his carnivorous counterpart. The great reduction in cancer risk enjoyed by vegetarians deserves part of the credit for this. Because the vegetarian menu is likely to be lower in fat than a meat diet, cancers of the colon, breast, and prostate are less likely. In addition, since fiber is found only in plants, vegetarian diets are likely to be higher in this potent cancer-fighter. Finally, beta-carotene and other vitamins have shown efficacy in cancer prevention in dozens of studies. The source of beta-carotene is dark green and yellow vegetables, such as spinach, broccoli, and carrots.
It is essential that the “War on Cancer” shift toward prevention and to new non-animal research methods. The old ones simply have not done the job. The death rate from cancer has not declined at all. It is, in fact, slowly increasing. It is clear that the needs of medicine will force a shift away from animal testing and encourage the booming vegetarian trend.
This does not mean, however, that the battle for animal protection has been won. Far from it. Too many researchers stay entrenched in the old ways of doing things. They need as much pressure as ever to begin genuine phase-outs of animal experimentation and testing. It’s essential to remember, and to let organizations and government agencies know, that new methods can streamline cancer research, while a reliance on outdated methods hurts people as well as animals.