Editorial: The Power of Clinical Research
Recent events teach us an important lesson about medical research. First came the sudden departure of Ohio State University veterinarian Michael Podell. In experiments that have become notorious, Podell gave methamphetamine, a commonly abused drug, and feline immunodeficiency virus (FIV) to about 40 cats, and he was planning on doing the same to five dozen more. His aim was to simulate the combined brain-damaging effects of HIV (a distant cousin of FIV) and amphetamines. Meanwhile, other research teams were already studying HIV-positive, drug-abusing humans directly, with the ability to detect the mild cognitive deficits, subtle language disorders, hallucinations, and delusions that Dr. Podell’s cat experiments were simply too crude to identify.
At about the same time as public pressure forced Podell to stop his experiments, federal researchers called an abrupt halt to another research program, the Women’s Health Initiative study of hormone replacement therapy (HRT). Women taking the estrogen-progesterone combination were found to have a higher risk of breast cancer, heart disease, strokes, and potentially fatal blood clots. The study was stopped and participants were asked to quit taking the drugs.
Now, imagine for a moment what would have happened if Michael Podell’s research methods had been used in the Women’s Health Initiative. What if, rather than examining women who were taking the medication in question, researchers had given hormones to cats, or perhaps to rats or mice? If the animals had developed adverse effects, researchers would have called the findings “suggestive” and “interesting,” and would have called only for more research—not for any actual change in clinical practice. And if the animals had not shown any problems from HRT, the studies would have been used as evidence of the treatment’s safety. In neither case would it have led to the result that clinical studies brought—an immediate and potentially lifesaving change in what doctors prescribe.
This is not to suggest that dangerous studies should be done in human patients. Quite the contrary. Had HRT not already been in common use, the study would not have been done. But equally unacceptable—ethically and scientifically—would be studies of other species; such studies simply could not settle the questions at hand. Had HRT not been in common use, the answer would have been to turn to epidemiological evidence of the effect of variations in estrogen levels, in-vitro studies of the effects of estrogens on tumor cells and normal tissues, and other studies that require no cross-species translation. Indeed, these techniques have supported the finding that HRT is a very risky proposition.
On the other hand, if Dr. Podell had used the methods of the Women’s Health Initiative—carefully and ethically studying human beings—it’s a safe bet that his work would have been above criticism and he would still be pursuing his research today.
Now, on the heels of these two events, a third issue splashed into the popular press: The high-protein Atkins Diet had been proposed as the naïve answer to America’s weight problems. Suddenly, doctors and reporters began debating the risks of the meat-laden diet. Does it work? Is it dangerous? And how will we sort all this out?
Just imagine if the Atkins diet were tested on animals—if scientists decided to feed meat to dogs or cats to see if it made them all svelte or posed any risks. Of course, the idea that such tests would tell us anything about humans is ludicrous.
Human clinical trials must always be conducted with the highest ethical and scientific standards. When they are, they give us the crucial answers we need to solve medical problems.
Neal D. Barnard, M.D.
President of PCRM