Heart disease and heart attack amplified in marijuana users
Recreational marijuana users who smoke more than once a month have an increased risk of heart attack and heart disease. According to new research from Stanford University, the psychoactive component of marijuana, tetrahydrocannabinol (THC), caused inflammation in endothelial cells that line the inside of blood vessels, as well as atherosclerosis, in studied mice.
It was later discovered that the inflammation could be blocked by a soybean-derived molecule called genistein, without changing THC’s pain-alleviating or sedating effects — characteristics vital to medicinal marijuana users.
A significant proportion of 500,000 study subjects who smoked marijuana more than once a month were found to be much more likely to have a heart attack before the age of 50 compared to non-users. The researchers showed that THC promotes inflammation and atherosclerosis in human endothelial cells grown in the laboratory. Similarly, mice bred to have high cholesterol levels and fed a high-fat diet developed significantly large atherosclerosis plaques when injected with THC at levels comparable to smoking one marijuana cigarette per day.
[While THC typically binds to a receptor called CB1 on cells in the human brain, heart, and vasculature, which regulate mood, pain perception, immune function and metabolism, frequent marijuana use causes inappropriate activation of CB1, which in turn causes inflammation and atherosclerosis. Inappropriate activation of CB1 is also associated with obesity, diabetes, and cancer.]
Further screening revealed a molecule capable of blocking the pro-inflammatory effects of THC whilst maintaining its psychoactive effects on the brain – genistein. Found in soybeans and fava beans, genistein does not cross the blood-brain barrier: in mouse studies, genistein reduced endothelial dysfunction in THC-treated mice without disrupting the drug’s effects on the animal’s central nervous system.
“Our studies of human cells and mice clearly outline how THC exposure initiates a damaging molecular cascade in the blood vessels,” said Stanford’s Dr. Mark Chandy. “[Genistein] is already used as a nutritional supplement, and 99% of it stays outside the brain, so it shouldn’t cause these particular adverse side effects.”
However, the researchers admit a more thorough clinical trial is needed to explore the greater effects of genistein on marijuana users and cardiovascular risk. The researchers also call for medical marijuana users to be aware of potential cardiovascular risks from using the drug.
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