Animal Studies Mislead Researchers
Faulty animal models mislead researchers and halt progress. The following examples highlight three instances where erroneous animal research significantly hindered scientific progress.
Abortion and Breast Cancer
In 1980, J. Russo and I.H. Russo published a paper in the American Journal of Pathology stating that in multiple experiments on pregnant rats, 77 percent of those who underwent an induced abortion developed breast cancer, whereas none of the rats who delivered their pups developed cancer.27 These shocking statistics convinced breast cancer researchers to focus time and money on studying the effects of abortion on cancer development. Following decades of fear and confusion, the National Cancer Institute, after reviewing the available epidemiological studies, declared that the belief that there is an abortion-breast cancer link is groundless.28
But the misleading research has caused Mississippi, Georgia, and other states to pass the Women’s Right to Know Act, which mandates that women seeking abortions must confirm that they have been told that abortion raises the risk of developing breast cancer. Several other state legislatures are currently considering similar bills based on this faulty science.
Depo-Provera
Many chemical forms of birth control can cause mood swings, weight gain, exhaustion, and other serious side effects, so having choices is crucial. One choice, Depo-Provera (“the shot”), is taken once every three months and is 99 percent effective. Women on Depo-Provera have a decreased risk of endometrial cancer, ovarian cancer, and pelvic inflammatory disease. They may also have less menstrual cramping and pain, fewer periods, and a lower risk of anemia. That’s why so many women now choose Depo-Provera for their contraceptive needs.
Because of misleading animal tests, Depo-Provera was not available in the United States for more than two decades. Although European women had used Depo-Provera safely for years, the U.S. Food and Drug Administration (FDA) looked to animal tests for proof that the method was safe. Unfortunately, Depo-Provera causes mammary tumors in rats, beagles, and baboons. As a result, the FDA refused to approve the drug. Now, decades later, scientists have conceded that the human data from Europe and elsewhere conclusively shows that Depo-Provera does not increase the risk of breast cancer.29 In this case, American women were denied a safe and effective form of contraception because animal models proved to be inaccurate.
Alcohol and Breast Cancer
Although epidemiology has strongly linked alcohol consumption to an increased risk of breast cancer, Carol Shively of Wake Forest University continues to challenge this conclusion with her animal data. Shively advises, “Postmenopausal women who are not on [hormone replacement therapy] can drink moderately without affecting their breast or endometrial cancer risk.”30 Shively based her conclusions on a study in which she trained macaques who had their ovaries removed to drink two alcoholic beverages a day. The macaques who drank alcohol did not develop mammary tumors more often than did the macaques who didn’t consume alcohol. From this observation, Shively concluded that moderate drinking is safe for human women.
Studies such as Shively’s continue to confuse women about their health choices and derail scientific advancement. Her results irresponsibly contradict countless human studies, including the famous Harvard Nurses’ Health Study, which showed that consuming two alcoholic drinks a day can raise a woman’s risk of breast cancer by up to 25 percent.31
27. J. Russo et al., “Susceptibility of the Mammary Gland to Carcinogenesis. II. Pregnancy Interruption as a Risk Factor in Tumor Incidence,” American Journal of Pathology 100 (1980): 497-512.
28. National Cancer Institute, “Abortion, Miscarriage, and Breast Cancer Risk, 23 Nov. 2005 <http://www.cancer.gov/cancertopics/factsheet/Risk/abortion-miscarriage>.
29. “DMPA and Breast Cancer: The Dog Has Had Its Day,” editorial, Lancet 338(8771) (1991): 856-7.
30. Steven Reinberg, “Stress May Raise Endometrial Cancer Risk: Animal Study Suggests That It Doubles Odds of Disease.” Women’s Health Issues. 13 Jul. 2004 <http://www.womenshealthissues.net/ms/news/520007/main.html>.
31. “Alcohol,” Harvard School of Public Health, 23 Nov. 2005 <http://www.hsph.harvard.edu/nutritionsource/alcohol.html>.
