are in Research
research indicates that cannabinoids may help protect against the development
of certain types of tumors. Most recently, a Spanish research team reported in
Nature that injections of synthetic THC eradicated malignant brain tumors - so-called
gliomas - in one-third of treated rats, and prolonged life in another third by
as much as six weeks. (1) Team leader Manuel Guzman
called the results "remarkable" and speculated that they "may provide
a new therapeutic approach for the treatment of malignant gliomas. (2)
An accompanying commentary remarked that this was the first convincing study to
demonstrate that cannabis-based treatment may combat cancer. (3)
Other journals have also recently reported on cannabinoids' antitumoral potential.
studies also indicate that cannabinoids may successfully stave certain types of
tumors. One study examined the effects of delta-9-tetrahydrocannabinol (THC),
delta-8-THC, and cannabinol (CBN) on cancer cells in mice lungs. Researchers reported
that cannabinoids reduced the size of the tumors by 25 to 82 percent, depending
on dose and duration of treatment, with a corresponding increase in survival time.
(8) A two-year federal study by the U.S. National
Toxicology Program found that mice and rats given high doses of THC over long
periods of time appeared to have greater protection against malignancies than
untreated controls. Researchers concluded that in both mice and rats, "the
incidence of benign and malignant neoplasms was decreased in a dose dependent
Dr. Lester Grinspoon writes in Marihuana: The Forbidden Medicine (with James Bakalar)
that other animal studies also suggest that some cannabinoids have tumor-reducing
Italian research team reported in 1998 that the endocannabinoid anandamide, which
binds to the same brain receptors as cannabis, "potently and selectively
inhibits the proliferation of human breast cancer cells in vitro" by interfering
with their DNA production cycle. (12,13)
Non-mammary tumor cells were not affected by anandamide. Clearly, further research
is necessary and appropriate.
Galve-Roperph et al. "Antitumoral action of cannabinoids: involvement of
sustained ceramide accumulation of ERK activation." Nature Medicine 6 (2000):
Bulletin. "THC destroys brain cancer in animal research," March 5, 2000.
Piomelli. "Pot of gold for glioma therapy." Nature Medicine 6 (2000):
Benard. "Cannabinoids, among others, send malignant tumors to nirvana."
Bull Cancer 87 (2000): 299-300.
Molnar et al. "Membrane associated with antitumor effects of crocine-ginsenoside
and cannabinoid derivatives." Anticancer Res 20 (2000): 861-867.
Ruiz et al. "Delta-9-tetrahydrocannabinol induces apoptosis in human prostate
PC-3 cells via a receptor-independent mechanism." FEBS Letter 458 (1999):
Baek et al. "Antitumor activity of cannabigerol against human oral epitheloid
carcinoma cells." Arch Pharm Res 21 (1998): 353-356.
Harris et al., "Anti-tumoral Properties of Cannabinoids," The Pharmacology
of Marihuana, ed. M. Braude et al., 2 vols., New York: Raven Press (1976) 2: 773-776
as cited by L. Grinspoon et al., Marihuana: The Forbidden Medicine (second edition),
New Haven, CT: Yale University Press (1997), 173.
J. James, "Unpublished Federal Study Found THC-Treated Rats Lived Longer,
Had Less Cancer," AIDS Treatment News 263 (1997).
and Carcinogenesis Studies of 1 trans-delta-9-tetrahydrocannabinol in F344N/N
Rats and BC63F1 Mice," National Institutes of Health National Toxicology
Program, NIH Publication No. 97-3362 (November 1996).
Grinspoon et al., Marihuana: "The Forbidden Medicine" (second edition),
De Petrocellis et al., The endogenous cannabinoid anandamide inhibits human breast
cancer cell proliferation, Proceedings of the National Academy of Sciences 95
Chemicals Might Inhibit Breast Tumors, Stroke Damage," Dallas Morning News,
July 13, 1998.