THC, or delta-9-tetrahydrocannabinol, is one of the many cannabinoids in marijuana.  Cannabinoids have been shown to be medically beneficial as analgesics and anti-nausea agents, among other findings.

Most recently, Swiss and German researchers have shown that a very small dose of THC slows the progression of atherosclerosis (clogging of the arteries) in mice.  It's a pretty amazing study, especially since atherosclerosis is the leading cause of heart disease, and strokes, in the world.

Look below the fold for details.

A compound derived from the cannabis plant protects blood vessels from dangerous clogging, a study of mice has shown. The discovery could lead to new drugs to ward off heart disease and stroke.

The compound, called delta-9-tetrahydrocannabinol (THC), combats the blood-vessel disease atherosclerosis in mice. This disease occurs when damage to blood vessels, by nicotine from cigarettes, for example, causes an immune response that leads to the formation of fatty deposits in arteries.

These deposits form because the immune cells can linger too long, recruiting others and leading to an inflamed blockage that snares fatty molecules. The disease is the leading cause of heart disease and stroke in the developed world.

THC seems to tone down this immune response, report François Mach of the University Hospital Geneva, Switzerland and his colleagues. The compound binds to a protein called CB2 that is present on the surfaces of certain immune cells.

In addition to CB2, there is another receptor called CB1.  Simply put, when THC binds to that one, you get high.  Anyway, the researchers in this study proved that THC had to bind to CB2 for it to slow atherosclerosis.  It didn't have any effect when it bound to CB1 (except possibly get the mice stoned).

The news release goes on to point out that:

The benefits for atherosclerosis occurred only at a certain dosage, Mach adds. At higher and lower doses, THC has no therapeutic effect on blood vessels, he says. He notes the similarly moderated effects of alcohol on heart disease, adding that a single glass of Bordeaux may reduce risk while overindulgence can increase it.

The team also emphasises that the THC dose required to protect blood vessels is lower, relative to body weight, than that which would produce the mind-altering altering effects of cannabis in humans. "This paper has nothing to do with smoking marijuana," Mach stresses.

The researchers speculate that perhaps cannabinoids could be used in conjunction with statins, which lower blood cholesterol levels.

Obviously, the effects of THC are complex.  However, the volume of literature that indicates the medical benefits of marijuana is obviously growing.  Someday, hopefully, lawmakers in all states will be convinced that marijuana should be decriminalized for medical use.