Source: Huffington Post

By Andrew Weil

12 September 2010

SEE TRAILER OF WHAT IF CANNABIS CURED CANCER?

If an American doctor of the late 19th century
stepped into a time warp and emerged in 2010, he
would be shocked by the multitude of
pharmaceuticals that today’s physicians use. But
as he pondered this array (and wondered, as I
do, whether most are really necessary), he would
soon notice an equally surprising omission, and
exclaim, “Where’s my Cannabis indica?”

No wonder — the poor fellow would feel nearly
helpless without it. In his day, labor pains,
asthma, nervous disorders and even colicky
babies were treated with a fluid extract of
Cannabis indica, also known as “Indian hemp.”
(Cannabis is generally seen as having three
species — sativa, indica and ruderalis — but
crossbreeding is common, especially between
sativa and indica.) At least 100 scientific
papers published in the 19th century backed up such uses.

Then
the [
Marihuana Tax Act->http://www.druglibrary.org/schaffer/hemp/taxact/mjtaxact.htm] of 1937 made possession or
transfer of Cannabis illegal in the U.S. except
for certain medical and industrial uses, which
were heavily taxed. The legislation began a long
process of making Cannabis use illegal
altogether. Many historians have examined this
sorry chapter in American legislative history,
and the dubious evidence for Cannabis addiction
and violent behavior used to secure the bill’s
passage. “Under the Influence: The
Disinformation Guide to Drugs” by Preston Peet
makes a persuasive case that the Act’s real
purpose was to quash the hemp industry, making
synthetic fibers more valuable for industrialists who owned the patents.

Meanwhile, as a medical doctor and botanist, my
aim has always been to filter out the cultural
noise surrounding the genus Cannabis and see it
dispassionately: as a plant with bioactivity in
human beings that may have therapeutic value.
From this perspective, what can it offer us?

As it turns out, a great deal. Research into
possible medical uses of Cannabis is enjoying a
renaissance. In recent years, studies have shown
potential for treating nausea, vomiting,
premenstrual syndrome, insomnia, migraines,
multiple sclerosis, spinal cord injuries,
alcohol abuse, collagen-induced arthritis,
asthma, atherosclerosis, bipolar disorder,
depression, Huntington’s disease, Parkinson’s
disease, sickle-cell disease, sleep apnea,
Alzheimer’s disease and anorexia nervosa.

But perhaps most exciting, cannabinoids
(chemical constituents of Cannabis, the best
known being tetrahydrocannabinol or THC) may
have a primary role in cancer treatment and
prevention. A number of studies have shown that
these compounds can inhibit tumor growth in
laboratory animal models. In part, this is
achieved by inhibiting angiogenesis, the
formation of new blood vessels that tumors need
in order to grow. What’s more, cannabinoids seem
to kill tumor cells without affecting
surrounding normal cells. If these findings hold
true as research progresses, cannabinoids would
demonstrate a huge advantage over conventional
chemotherapy agents, which too often destroy
normal cells as well as cancer cells.

As long ago as 1975, researchers reported that
cannabinoids inhibited the growth of a certain
type of lung cancer cell in test tubes and in
mice. Since then, laboratory studies have shown
that cannabinoids have effects against tumor
cells from glioblastoma (a deadly type of brain
cancer) as well as those from thyroid cancer¸
leukemia/lymphoma, and skin, uterus, breast,
stomach, colorectal, pancreatic and prostate cancers.

So far, the only human test of cannabinoids
against cancer was performed in Spain, and was
designed to determine if treatment was safe, not
whether it was effective. (In studies on humans,
such “phase one trials,” are focused on
establishing the safety of a new drug, as well
as the right dosage.) In the Spanish study,
reported in 2006, the dose was administered
intracranially, directly into the tumors of
patients with recurrent brain cancer. The
investigation established the safety of the dose
and showed that the compound used decreased cell
proliferation in at least two of nine patients studied.

It is not clear that smoking marijuana achieves
blood levels high enough to have these
anticancer effects. We need more human research,
including well-designed studies to find the best mode of administration.

If you want to learn more about this subject, I
recommend an excellent documentary film,
“What if Cannabis Cured Cancer,” by Len Richmond,
which summarizes the remarkable research
findings of recent years. Most medical doctors
are not aware of this information and its
implications for cancer prevention and
treatment. The film presents compelling evidence
that our current policy on Cannabis is counterproductive.

Another reliable source of information is the
chapter on cannabinoids and cancer in
“Integrative Oncology” (Oxford University Press,
2009), a textbook I edited with integrative
oncologist Donald I. Abrams, M.D. (Learn more
about [integrative
cancer treatment from Dr. Abrams->http://www.drweil.com/drw/u/ART03060/Treating-Cancer-With-Integrative-Medicine.html].)

After more than 70 years of misinformation about
this botanical remedy, I am delighted that we
are finally gaining a mature understanding of
its immense therapeutic potential.

Andrew Weil, M.D., invites you to join the
conversation: become a fan on
Facebook, follow
him on Twitter, and
check out his Blog. Dr. Weil is the founder and
director of the
[Arizona
Center for Integrative Medicine->http://integrativemedicine.arizona.edu] and the editorial director of www.DrWeil.com.

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