Americas War on Carcinogens: Reassessing the Use of Animal Tests to Predict Human Cancer Risk by the American Council on Science and Health (March 2005); $15.95.
Americas War on Carcinogens: Reassessing the Use of Animal Tests to Predict Human Cancer Risk calls for medical researchers, journalists, and lawmakers to refocus and change the rules of engagement in the war on cancer, the second-leading cause of death in the United States.
Written by a team of Ph.D.s and M.D.s for the American Council on Science and Health, this book suggests that animal research has done more damage than good. A fast read, this 150-page paperback, supported by 16 pages of references, debunks the assumption that a mega-dosed rat is a human being.
The dispute occurs when a suspected carcinogen is put on trial for violating the Delaney clause, a provision in the 1958 Food, Drug, and Cosmetic Act that requires FDA approval for new food additives to be marketed:
No additive shall be deemed to be safe if it is found to induce cancer when ingested by man or laboratory animals or if it is found, after tests which are appropriate for the evaluation of the safety of food additives, to induce cancer in man or animals.
The American Council on Science and Health (ACSH) experts validate the idea that, despite any supposedly good intentions, this law has not protected us from cancer. Instead, the side effects have gone too far, to the point of depriving us of food that is harmless if not actually good for us as part of a regular diet.
Chapter nine investigates a 40-year chronology of 11 health scares, the results of various applications of the Delaney clause. The Cranberry Scare in 1959 set a precedent after rats on large doses of aminotriazole tested positive for thyroid cancer. When trace amounts of the weed killer were found in a shipment, cranberries were taken off the table for Thanksgiving that year, and the prejudice lingered for years. The ACSH authors conclude,
Although the dose of the herbicide used in the animal carcinogen test was the equivalent of a person ingesting 15,000 pounds of cranberries every day for years, the presence of any amount of aminotriazole on the berries was considered unacceptable because of the Delaney clause.
The strongest indictment of federal law and the application of Environmental Protection Agency (EPA) policies, however, is described in the brief section on DDT. Rachel Carsons 1962 book, Silent Spring, overlooked the insecticides enduring power to kill mosquitoes and contain malaria. Instead, emphasis was placed on its toxic effect on bird habitat and on human health. Even though further research challenged those claims, the EPA banned DDT in 1972. After reexamining the evidence, the authors of Americas War on Carcinogens argue that, during the 20 years of its highest use, DDT had saved at least 100 million lives that would otherwise have been lost to malaria or other insect-borne diseases. Moreover, the authors argue that Third World countries used DDT because it was inexpensive, effective for six months, and safe for humans.
Claims that DDT caused human cancer began with an error-filled 1969 study in which aflatoxin in moldy feed, not DDT, caused liver cancer and leukemia in mice. Since then, studies on humans have found no link between DDT and liver or breast cancer, as once alleged. As a result of diminished production, diminished availability, and restricted use of DDT around the world, human life has been exposed to the malaria mosquito. The ACSH researchers estimate that that increased exposure has caused the unnecessary deaths of at least 30 million people.
Bursting health myths
The book is packed with other myth blowers. Some bans block beneficial chemicals, such as the artificial low-calorie sweeteners that replace sugar, including cyclamate (1969 ban) and saccharin (1977 ban). Although high intake of sweeteners caused bladder tumors in rats, comparative studies with humans, including diabetics, have detected no cancer risk.
Are hot potatoes harmful to human health? Swedish scientists claimed they were during a 2002 acrylamide scare, in spite of the fact that humans have eaten potatoes for thousands of years. Other researchers have countered that to assume all carcinogens are dangerous ignores the fact that people daily eat more carcinogenic foods from nature than from synthetic additives. Natural carcinogens are all around us in plants. Vegetables such as beets, celery, lettuces, kale, and cabbages, to name a few, contain nitrates, which convert into nitrites, a rat carcinogen. But that doesnt mean these foods are human carcinogens.
Then there was the 2003 alarm over PCB (polychlorinated biphenyl) levels in farmed salmon (not yet banned), although eating omega-3 fish is encouraged to combat heart disease and cancer. The ACSH authors inject some perspective. If we believed the environmentalists, we would have to limit our protein intake from other animals because similar PCB levels (less than 1.5 percent of the 2,000 parts per billion allowable for human health by the FDA) have been found in roasted chicken breast and beef loin steak. Finally, ACSH studies in 1997 had found no health threats to humans from high buildups of PCBs, once used as industrial insulation, partly because PCB levels have been declining in the environment since 1974.
The misinterpretation of animal data leads to a misalignment of focus and resources. Because too many substances are labeled cancer risks on the basis of rat studies, Americas War on Carcinogens urges the U.S. Congress, the National Cancer Institute (NCI), the National Toxicology Program, and the EPA to reevaluate scientific testing.
As advocates for repeal of the Delaney clause, the American Council on Science and Health experts want the law replaced with common sense. They want to see the public more fully informed about the real causes of cancer, such as cigarette smoking, sun overexposure, sex-related diseases, occupational hazards, and family genetics. Then research can be developed for better screenings and treatments.
If more evidence is needed to build a convincing case against the damaging effects of government regulation, Americas War on Carcinogens is a source. This is a book to help balance the perspective of every classroom science teacher, university department head, medical professional, and researcher. Clearly the lawmakers should take note.
February 4, 2006
Rosalind Lacy MacLennan is a freelance writer and a cancer survivor.