About
Nutrition
Why Plants Are
(Usually) Better Than Drugs
By Andrew Weil, M.D.
HUFFPOST HEALTH November 19, 2010
I have always been fascinated by the difference between plants and
the drugs that are isolated from them. This goes back to my student
days at Harvard in the 1960s, where I received my undergraduate
degree in botany, and then went on to medical school. It's rare --
too rare, I have to say -- for botanists to become doctors. The
experience gave me a unique perspective on health and medicine.
For four decades, I've been skeptical of a prevailing belief in
Western medicine: when a plant shows bioactivity in humans, we must
attribute that effect to a single, predominant compound in the
plant. We label that the "active principle," isolate it, synthesize
it, and make a pharmaceutical out of it. Then, typically, we forget
about the plant. We don't study any of the other compounds in it or
their complex interactions.
This belief persists for two reasons. First, it makes research much
easier. Single compounds can be manufactured in pure, standardized
dosages, which simplifies clinical trials. (However, technology has
largely solved this problem. Modern growing and processing methods
make it possible to produce standardized, complex, whole-plant-based
medicines. Clinical trials of these compounds have become quite
sophisticated, especially in Europe.)
Second, and this is clearly the major reason, it makes drugs far
more profitable for drug companies. Isolating and synthesizing a
single molecule allows a drug company to patent that molecule.
Making slight chemical modifications allows further patent
potential. Such exclusivity can be worth billions, whereas a whole
plant offers little opportunity for profit.
Expensive as it is to the consumer, this faith in "single-agent"
drugs would be acceptable if they actually yielded better results.
But the fact is, the natural, whole plant often has both benefits
and safety that put the isolated compounds to shame.
Medicinal plants contain a wide array of chemical compounds. At
first, this looks like chaos, but more investigation reveals a
distinct order. Natural selection pressures push a plant to "try
out" variations on molecules to enhance the plant's odds of
surviving stressful environments. So, often, one molecule is present
in the greatest amount and has the most dramatic effect in a human
body -- but along with it are variations of that molecule in the
same plant.
For example, for several years, I did ethnobotanical study in South
America, researching native uses for coca leaf, which most of us
know only as the source of the isolated, problematic, addictive drug
cocaine. For Andean Indians, whole coca leaf is the number one
medicinal plant. They use it to treat gastrointestinal disturbances;
specifically, for both diarrhea and constipation. From the
perspective of Western pharmacology, this makes no sense. Cocaine
stimulates the gut, it increases bowel activity, so obviously it
would be a good treatment for constipation, but what could it do for
diarrhea except make it worse?
However, if you look carefully at the coca leaf's molecular array,
you find 14 bioactive alkaloids, with cocaine in the greatest
amount. While cocaine acts as a gut stimulant, other coca alkaloids
can have precisely the opposite action, they inhibit gut activity.
This means that when you take the whole mixture into the body, the
potential is there for the action to go in either direction. What
decides it? The state of the body, which is a function of which
receptors in the gut's tissues are available for binding. During my
time in Andean Indian communities, I collected many reports about
whole coca's paradoxical, normalizing effect on bowel function, and
experienced it firsthand, as well.
Herbs like coca that can "tone" the body and bring it back to
homeostasis are known as adaptogens, a term coined by Soviet
physician and scientist Nikolai Lazarev in 1947. Examples include
schisandra, reishi mushroom, eleutherococcus and ginseng. Asian
ginseng, for example, has an array of active constituents known as
ginsenosides. One of them, Rg1, can stimulate the nervous system,
while another, Rb1, has been found to calm it. But even this is an
oversimplification. Other constituent cofactors apparently increase
the adaptogenic properties of ginseng, making the therapeutic whole
more than the sum of its parts. Ultimately, this non-specific
response boosts resistance to stress -- whether the stress is
physical exertion, infection, or some other problem.
So using whole-plant remedies is a fundamentally different -- and, I
would argue, often better -- way to treat illness. In Western
medicine, we typically give the body no choice. We use single
compounds that, essentially, shove physiology in one direction.
Let me be clear -- sometimes, that is very appropriate and valuable,
if the body is dramatically out of balance and must get back on
track very quickly. For example, during a case of anaphylactic
shock, there is no time for the body's receptors to select specific
effects, so a drug such as pure epinephrine can be lifesaving.
But in many cases, particularly with the chronic, degenerative
diseases of modern civilization, there is time to allow the body to
participate, to choose just what it needs. As it slowly heals, it
can develop a new balance; a dynamic equilibrium that helps it cope
with stress in the future.
Human beings and plants have co-evolved for millions of years, so it
makes perfect sense that our complex bodies would be adapted to
absorb needed, beneficial compounds from complex plants and ignore
the rest. This is an established fact in nutrition, but the West's
sharp distinction between food and medicine somehow blinds us to
these properties when it comes to botanicals. The most successful
medical philosophies make no such division -- Okinawans, the world's
longest-lived people, believe that the food they eat is "nuchi gusui"
which roughly translates as "medicine for life."
So I will continue in my lifelong skepticism, and persist in my
belief that plants are (usually) better than pharmaceutical drugs.
Andrew Weil, M.D., is a world-renowned leader and pioneer in the
field of integrative medicine.
Combining a Harvard education and a lifetime of practicing natural
and preventive medicine, Dr. Weil is the founder and director of the
Arizona Center for Integrative Medicine at the University of
Arizona Health Sciences Center, where he is also a Clinical
Professor of Medicine and Professor of Public Health and the
Lovell-Jones Professor of Integrative Rheumatology. Dr. Weil
received both his medical degree and his undergraduate AB degree in
biology (botany) from Harvard University.
Dr. Weil is an internationally-recognized expert for his views on
leading a healthy lifestyle, his philosophy of healthy aging, and
his critique of the future of medicine and health care.
Approximately 10 million copies of Dr. Weil's books have been sold,
including Spontaneous Healing, 8 Weeks to Optimum Health, Eating
Well for Optimum Health, The Healthy Kitchen, Healthy Aging, and Why
Our Health Matters. |