As you assess what appears to be science in the news and the popular
literature, it might be helpful for me to share with you some basic
lessons that I have learned during my career in science. While you may
be well aware of some of the points I am about to make, others may not
be quite so obvious. Much of this was recently reinforced in my own
mind in an Encore class, “What Science Is and What Science Isn’t”. Dr.
Hubitz, a Physics professor with many years experience in teaching and
evaluating science, felt that the general public was often misled by
what they believed to be valid science. It was a great course from my
point of view because I could relate a broad range of misinterpretations
from flying saucers, chiropractic treatment and many other subjects to
my own experience in interpreting results of various clinical trials in
my work at Bristol-Myers Squibb.
I don’t intend to judge any particular concept here but I will simply
cite recent interest in the reported benefits of particular diets as a
generalized example to point out the series of intellectual layers that
need to be addressed. It’s sort of like an alien from another world
arriving on earth never having seen any type of plant, trying to
understand the role of a coconut in a palm tree. He would need to start
at the roots and work up through progressive layers of understanding.
To claim that reported results have come about through scientific
investigation implies the use of the scientific method in achieving
those results. The scientific method demands a well-defined sequence of
steps beginning with a clearly defined hypothesis, e.g., such and such a
food is harmful to one’s health. In such a case the hypothesis should
be refined as much as possible. For example, what is the specific
harmful effect believed to be caused by the food? What population
(demographics) is susceptible to the suggested harmful effect? What
dose of the food is believed to be harmful? etc.,etc.
Once a clear hypothesis is formulated, a well-controlled study is
designed to test the hypothesis. A homogeneous target population is
identified, test conditions are established with sufficient numbers of
subjects to yield statistically meaningful results and all potential
variables are held constant, except the variable being tested and this
is varied in a systematic way in order to study important parameters
such as dose-response relationships. Reproducible findings are then
needed from other investigators to confirm the hypothesis. It’s
unlikely that there has ever been a human dietary study that meets these
strict standards. It would be nearly impossible to control all
variables in a human’s life other than one specific dietary factor. For
this reason nearly all data regarding diets and health come from
retrospective surveys. Additionally, results of this kind are only
correlations, which do not establish a cause and effect relationship.
That’s not to say that such results are of no value. They may be quite
informative, but we need to recognize that retrospective data, in
general, are far less reliable than results obtained from
well-controlled prospective studies. It’s always a good idea to get a
good handle on the full range of opinions. Where is there nearly
unanimous concurrence and where are there credible divergent opinions?
The perspective I would bring to this, based on my experience with
numerous clinical trials of various new pharmaceutical therapies, is
that even in the case of very carefully conducted, well designed,
prospective trials, results can and often do vary from one study to the
next. In fact the typical NDA presented to the FDA for approval of a
specific indication might contain five large trials of several hundreds
or thousands of patients each, three of which are positive for the new
drug, one negative and one neutral. You virtually never get a totally
clean picture, even with tightly controlled studies. Human biology is
incredibly complex and variable. Responses to nearly all interventions
reflect this.
Nearly all health care workers are familiar with the very powerful
effect the human mind can have on health and disease, from the medicine
men of primitive societies, to faith healers and to most doctors and
nurses. A positive mental attitude has often been observed to play a
substantial role in recovering from an illness. Conversely, there are
many reports of voodoo and other “evil” spells associated with sickness
and even death. There is a whole field of medicine; “psychosomatics”
that deals with mentally induced illness. While I must admit that little
if any of this is based on trials conducted by the “scientific method”,
most of us are personally familiar with the strong effect mental
attitude has on our lives. Thus, if you have a strong belief that a
particular diet or behavior is beneficial to you, chances are it will
be, at least via the psychosomatic route and you should usually follow
your instincts.
Finally, there was a statement in a recent article on diet and health
that I strongly agree with. The best judge of what is good for you is
your own body. Listen to it and follow what it is telling you. If you
feel good and are happy with your choices and your life style, stay with
it. If you feel improvement is needed, look for those things that
benefit you as an individual. There is no such thing as a “one size
fits all” lifestyle. Keep in mind the powerful effect of a positive
mental attitude.
