Cannabis Helps - Blood Pressure

High blood pressure, or hypertension, afflicts between 10 and 20 percent of adults in Western societies. This condition puts a strain on the heart and blood vessels and greatly increases the risk of stroke and heart disease.

Research is currently being conducted at the University of Nottingham Medical School (U.K.) to better determine the effects of endocannabinoids, cannabis-like chemicals produced naturally by the body, on circulation. (1) Scientists recently discovered that the endocannabinoid anandamide relaxes blood vessels, which can reduce blood pressure by allowing blood to flow more freely, but do not yet comprehend how they are produced or cause changes in the body. (2)

Lead researcher Dr. David Kendall of the Queen's Medical Centre says: "This research should tell us a great deal more about how these substances affect our circulation. This is a new and exciting area of research which could ultimately lead to better treatments for a range of cardiovascular diseases." (3)

In his book Marihuana the Forbidden Medicine, Dr. Lester Grinspoon (with James Bakalar) recounts one patient's account of using cannabis to successfully treat hypertension. "Cannabis is … the first drug that has been effective in controlling my high blood pressure," the patient writes. "I have taken so many others that I can't remember their names, but the result was always the same: they either didn't work or caused such horrible side effects that I needed more drugs, which only raised my blood pressure again. Since I began smoking cannabis, my blood pressure has remained relatively constant at 130 over 80." (4)

Former California gubernatorial candidate Steve Kubby also gives strong anecdotal evidence of cannabis' ability to control hypertension. Kubby has used inhaled marijuana to control hypertension associated with malignant pheochromocytoma, a usually fatal cancer he contracted 15 years ago. (5) Several of Kubby's phsysicians, including Dr. Vincent DeQuattro of the hypertension diagnostic laboratory at the University of Southern California Medical School, speculate that his marijuana therapy may have extended his life. "In some amazing fashion, this medication has not only controlled the symptoms of the disease, but in my view, has arrested growth," DeQuattro says. He adds that he knows of no other patient who has survived as long with the disease. (6)

The House of Lords Science and Technology Committee report on medical cannabis acknowledged that smoking cannabis can lower blood pressure, but warns that it may also increase heart rate in some users (7). They concluded that the latter effect may pose a health risk for patients with a history of angina or other cardiovascular disease, and recommend that they be excluded from any clinical trials of cannabis-based medicines. (8)

Similarly, a 1982 Institute of Medicine report, "Marijuana and Health," also warned of cannabis' acute effects on circulation. Researchers wrote "human blood pressure usually increases moderately on acute administration of delta-9-THC," but noted that it typically slows heart rate in non-human mammals. (9)

While cannabis may potentially be beneficial in reducing blood pressure, specific studies have not been conducted to determine how safely and effectively it controls this condition. Studies on anandamide and hypertension should provide clues as to how cannabis affects blood pressure; however these studies are still in their initial stages. Therefore, patients suffering from high blood pressure should approach the idea of medical cannabis cautiously, and should likely consider alternative therapies until further research is completed.

References used above
1."Body's 'cannabis' could hold blood pressure key," BBC, December 29, 1998.
2. "Science: Research on the properties of endocannabinoids to reduce blood pressure," ACM Bulletin, January 10,