Artificial Sweetener Studies Underscore Risk of Relying on Animal Testing
By John J. Pippin, M.D., F.A.C.C.
This piece was published April 23, 2006, in the Charleston Gazette.
It may be wise to limit your pet rat’s intake of diet soda. Or so suggests a study of 1,800 rats reported by Italian scientists last year, in which aspartame caused lymphomas and leukemias—but only in the females. Three previous studies of another artificial sweetener showed that bladder cancers occurred in the offspring of rats given saccharin—but only in the males.
The Italian study results triggered consternation about the safety of aspartame, the sweetener used in many popular diet sodas and other food products. So National Cancer Institute scientists conducted a huge epidemiological study of more than 566,000 people to determine if aspartame causes cancers in people. As reported at a recent meeting of the American Association for Cancer Research, the study found that it does not. More than 30 clinical studies and more than 100 years of widespread use have shown the same for saccharin.
The failure of animal tests in these cases would be merely an interesting curiosity were it not for the toll taken by wrong results. Take the drug Vioxx, for example—or rather, don’t take Vioxx.
In at least eight studies in six animal species, Vioxx was not only safe but often beneficial for protection from heart and blood vessel disease. Yet this drug caused an estimated 150,000 cases of heart attacks, strokes and heart failure in the United States, including about 60,000 deaths. That’s more Americans than died in the Vietnam War.
It is not the animals’ fault. The fact is, we don’t look like rats and mice. And very often, we don’t test like them either. The Food and Drug Administration reports that 92 percent of drugs that test successfully in animals fail during human trials and that over half the 8 percent that are approved get relabeled or withdrawn due to serious adverse effects.
Why doesn’t the public know this? Because while the headline-grabbing animal research breakthroughs become common knowledge, the consistently disappointing human results that follow are seldom reported. Thus the public is left with the impression that all animal research produces human benefits, a falsehood that sustains the industry but misleads the public. The billions of dollars annually used for animal testing otherwise could support more modern human-based testing methods that may produce the benefits animal research has failed to achieve.
An enormous cost in dollars and in lives has come from the reliance on animal tests in cancer research. In 1998, a former director of NCI stated: “The history of cancer research has been a history of curing cancer in the mouse. We have cured mice of cancer for decades, and it simply didn’t work in humans.”
In other words, the war on cancer has so far been lost largely due to an emphasis on animal research rather than preventive measures for people. That claim is bolstered by the 2002 emergence of cancer as the leading cause of death in Americans younger than 85.
A potentially better research approach is followed by NCI, which uses a panel of 59 human tumor cell lines to evaluate potential cancer drugs and another panel of about 100 human cell lines to test substances for cancer causation.
Aspartame may or may not have other health-related effects, and a spirited battle continues about those claims and counter-claims. But as with the aspartame cancer scare, one thing is certain about these other potential risks: The truth will not come from a blind reliance on crude and unscientific animal tests, but from well-crafted and ethical studies focused on human biology.
Cardiologist John J. Pippin, M.D., F.A.C.C., is a senior medical and research advisor with the Physicians Committee for Responsible Medicine.