For several years I have postulated that marijuana is not, in the strict sense of the word, an intoxicant.

As I wrote in the book Marijuana Is Safer: So Why Are We Driving People to Drink? (Chelsea Green, 2009), the word ‘intoxicant’ is derived from the Latin noun toxicum (poison). It’s an appropriate term for alcohol, as ethanol (the psychoactive ingredient in booze) in moderate to high doses is toxic (read: poisonous) to healthy cells and organs.

Of course, booze is hardly the only commonly ingested intoxicant. Take the over-the-counter painkiller acetaminophen (Tylenol). According to the Merck online medical library, acetaminophen poisoning and overdose is “common,” and can result in gastroenteritis (inflammation of the gastrointestinal tract) “within hours” and hepatotoxicity (liver damage) “within one to three days after ingestion.” In fact, less than one year ago the U.S. Food and Drug Administration called for tougher standards and warnings governing the drug’s use because “recent studies indicate that unintentional and intentional overdoses leading to severe hepatotoxicity continue to occur.”

By contrast, the therapeutically active components in marijuana – the cannabinoids – appear to be remarkably non-toxic to healthy cells and organs. This notable lack of toxicity is arguably because cannabinoids mimic compounds our bodies naturally produce – so-called endocannabinoids – that are pivotal for maintaining proper health and homeostasis.

In fact, in recent years scientists have discovered that the production of endocannabinoids (and their interaction with the cannabinoid receptors located throughout the body) play a key role in the regulation of proper appetite, anxiety control, blood pressure, bone mass, reproduction, and motor coordination, among other biological functions.

Just how important is this system in maintaining our health? Here’s a clue: In studies of mice genetically bred to lack a proper endocannabinoid system the most common result is premature death.

Armed with these findings, a handful of scientists have speculated that the root cause of certain disease conditions – including migraine, fibromyalgia, irritable bowel syndrome, and other functional conditions alleviated by clinical cannabis – may be an underlying endocannabinoid deficiency.