People with cancer who must undergo radiation and chemotherapy frequently stop treatments rather than suffer the nausea, pain, and other unpleasant side effects. Years before any state had authorized the medical use of cannabis, a 1991 Harvard Medical School study revealed that nearly half (44%) of U.S. oncologists were recommending cannabis to their patients as a way of mitigating the side effects of cancer treatments.

In its 1999 review, the Institute of Medicine concluded that cannabis could be a valid alternative for many people living with cancer. Specifically, the IOM notes, “In patients already experiencing severe nausea or vomiting, pills are generally ineffective, because of the difficulty in swallowing or keeping a pill down, and slow onset of the drug effect.”

Since the release of the IOM report, new research has been published which supports the use of cannabis to curb the debilitating effects of cancer treatment. In 2001, a review of clinical studies conducted in several states during the past two decades revealed that, in 768 individuals with cancer, cannabis was a highly effective anti-emetic in chemotherapy. Other studies have concluded that the active components in cannabis produce palliative effects in cancer patients by preventing nausea, vomiting and pain and by stimulating appetite.

The tumor-fighting properties of cannabinoids have also been demonstrated in numerous laboratory studies, though not yet in human clinical trials. Researchers have observed that “these compounds have been shown to inhibit the growth of tumor cells in culture and animal models by modulating key cell-signaling pathways. Cannabinoids are usually well tolerated, and do not produce the generalized toxic effects of conventional chemotherapies.”