Animals in Research Facilities / 101would have us believe. Most of the signifi cant advances in medi-
cine have come from studies of humans, not animals. For instance,
Neal Barnard, president of the Physicians Committee for Responsi-
ble Medicine (PCRM), pointed out that “the risk factors that contrib-
ute to heart disease were identifi ed in human population studies
and tested in human clinical trials. Animal studies offer no greater
insight into this issue.”^52 Because those who conduct research on
animals do not critically examine the practice, they continue to use
animals largely because it would be politically, economically, and
institutionally diffi cult to question the status quo.^53 And because
there are no systematic reviews of the research conducted on ani-
mals, many experiments duplicate existing results and pose ques-
tions already answered.^54 A review of highly cited animal studies
published in leading scientifi c journals reports that only about one-
third of the research was replicated among human subjects. The
authors conclude that “patients and physicians should remain cau-
tious about extrapolating the fi ndings of prominent animal research
to the care of human disease.”^55 In addition, opponents argue that
animals do not respond to drugs in the same ways that humans do
and therefore conclusions drawn from animal research have some-
times resulted in harm to human beings. Numerous medications
that have been successful in animal tests and have thus reached the
market, they point out, have resulted in human illness and death.
One notable case concerns the drug thalidomide, widely marketed
during the 1950s to pregnant women for morning sickness, partic-
ularly in Britain. In tests, animals tolerated massive doses of the
drug; when taken by pregnant women, it resulted in serious birth
defects. A recent example involves the arthritis drug Vioxx, which
was taken off the market after it caused an estimated sixty thou-
sand deaths. Animal research had shown it to be safe and benefi -
cial—to animals’ hearts.^56
Finally, opponents criticize animal research on moral grounds.
Many point out that, regardless of the promise the research holds,
it is morally objectionable to use nonhuman animals for human
ends. According to opponents, we cannot justify experimenting on
animals simply because they are not humans. Most people would