Flashback Friday: Evidence-Based Medicine or Evidence-Biased?

November 3, 2019 0 By Ewald Bahringer


“Evidence-Based Medicine or Evidence-Biased?” Dr. Esselstyn’s landmark study showing even advanced
triple vessel coronary artery disease could be reversed with a plant-based diet has been
criticized for being such a small study, but the reason we’re used to seeing such large studies
is that they typical show such small effects. Drug manufacturers may need to study 7,000 people in order to show a barely statistically significant
15% drop in ischemic events in a subsample of patients, whereas Esselstyn got a 100% drop
in those who stuck to his diet, all the more compelling given that those 18 participants
experienced 49 coronary events, such as heart attacks, in the eight years before they went on the diet. And these were the worst of the worst, most of
whom having already failed surgical intervention. And so when the effects are that dramatic how many people do you need? Before 1885, symptomatic rabies was
a death sentence until July 6th, when little Joseph Meister became the first
to receive Pasteur’s experimental rabies vaccine. The results of this and one
other case were so dramatic compared with previous experience that the new treatment was accepted
with a sample size of two. So dramatic compared with previous experience, no randomized controlled trial was necessary. Would you — having been infected by a rabid dog — be willing to participate in a randomized controlled trial (RCT) when being in the control group had
a certainty of a ”most awful death”? Sadly, such a question is not entirely rhetorical. In the 1970’s, a revolutionary treatment
for babies with immature lungs called ECMO – extracorporeal membranous oxygenation – transformed mortality in these babies
from 80% down to 20% nearly overnight, from 80% dead to 80% alive. Despite this dramatic success, they felt forced
to perform a randomized controlled trial. They didn’t want to. They knew they’d be condemning babies to death. They felt compelled to perform such a trial because
their claim that ECMO worked would, they judged, carry little weight amongst their medical colleagues
unless supported by a randomized controlled trial. And so at Harvard’s Children’s Hospital 39 infants
were randomized to either get ECMO or not — just be consigned to conventional medical therapy. They decided to stop the trial after the
fourth death so as not to kill too many babies. And that’s what they did. The study was halted after the fourth
conventional medical therapy death, at which point nine out of the nine
ECMO babies had survived. Imagine being the parent of one
of those four dead children. Just as one can imagine
being the child of a parent who died from conventional medical
or surgical therapy for heart disease. Medical students in the United States
are taught very little about nutrition. Worse yet, their training actually
biases them against the studies that show the power of dietary
approaches to managing disease, by encouraging them to ignore
any information that does not come from double-blind, randomized controlled trials. Yet human beings cannot easily
be blinded to a dietary intervention. They tend to notice what they’re eating. As a result, physicians may be
biased in favor of drug treatments and against dietary interventions
for the management of chronic disease. Evidence based medicine is a good thing. However, the medical profession may be focusing too much
on one type of evidence to the exclusion of all others, degenerating into a ignoring-most-of-the
-truly-important-evidence based medicine. And heart disease is the perfect example. On a healthy enough plant based diet, our #1 cause of death may simply cease to exist. The Cornell-Oxford-China Study showed that even
small amounts of animal-based food was associated with a small, but measurable increases in
risk of some of these chronic diseases. In other words, the causal relationship between dietary patterns
and coronary artery disease was already well established before Ornish and Esselstyn
undertook their clinical studies. The value of their studies was not so much in providing
evidence that such dietary changes would be effective, but in showing that physicians can persuade
their patients to make such changes, and also providing interesting data on the speed and magnitude of the
change in severe atherosclerotic lesions as a result of dietary therapy. So any complaints that these studies were
small or unblinded are simply irrelevant, because the evidence of the role of diet in
causing atherosclerosis is already so overwhelming, you know, assigning a patient to a control group eating the standard American diet could
be considered a violation of research ethics. Evidence of the value of plant-based
diets for managing chronic disease has been available in the medical
literature for decades: Kempner at Duke, John McDougall, The Physician’s
Committee for Responsible Medicine. Denis Burkitt had warned us that
the standard Western diet is a standard cause of death and disability
in the Western world for decades. Yet physicians in the US are still busily staffing the ambulances
at the bottom of the cliff instead of building fences at the top.