Weed is stronger than ever, but it might not affect our brains that much: 6 surprising facts about cannabis

Weed, reefer, Mary Jane, chronic.

Whatever you want to call it, cannabis has a lot of names — and a lot of uses — for a humble plant. Since it was legalized in Canada in 2018, the plant and its compounds have fuelled a steadily -growing market that offers everything from pre-rolled joints to gummies, soft drinks, vaporizers and oils.

In Science & Cannabis, a documentary from The Nature of Things, we discover how scientists are trying to untangle the health claims and benefits made about the "miracle weed" and distinguish the myths from the medicine.

Today's cannabis is a lot stronger than it used to be

Your parents' pot was much weaker than what you'll find in the stores today. Back in the '60s, '70s and '80s, marijuana had a THC content of less than two per cent. But since the '90s, the amount of THC — the chemical component that gets you high — has climbed significantly.

With the legalization of recreational cannabis, the industry has developed strains and products with much higher potency than ever before. Today's weed can reach 15 per cent THC or more, and concentrated products like oils, edibles and glass-like products called shatter can have a THC concentration as high as 90 per cent.

Unfortunately, the more potent a drug and its high is, the more addictive it can be. Today, about one in 11 marijuana users will become addicted.

Weed was the first online sale

It was sometime between 1971 and 1972 and it was illegal at the time, but the first e-commerce transaction was for a bag of weed.

Using ARPANET, a precursor to the internet, students at Stanford University struck a deal with students at MIT for the sale of an undetermined amount of marijuana.

This transaction wasn't like buying cannabis products online today. There was no exchange of money over the early web. Instead, the details of an in-person deal were "hashed out" over ARPANET.

Cannabis has over 100 active cannabinoids

You've likely heard of THC (tetrahydrocannabinol) and CBD (cannabidiol), but they're only two of more than 100 cannabinoids.

Cannabinoids are compounds that can be found in the cannabis leaf, stem and bud. They've become widespread in products that you can smoke, eat, vape, drink or rub on your skin, and are increasingly used to alleviate everything from pain to anxiety. But the full effects of cannabinoids are still being determined.

Because cannabis has been illegal for so long, researching its compounds has been somewhat difficult. Now, new and ingenious products are entering the market at such an incredible pace, and scientists are playing catch-up.

People have used cannabis for thousands of years

Even though different countries and cultures have different views on cannabis use, humans have been using the stuff for millennia.

Cannabis was first domesticated in East Asia, where it grows naturally. For about 4,000 years, humans have used its fibres to make hemp rope and clothing, and the plant's oily seeds for food. Cannabis seeds have even been found with Japanese pottery shards dated to about 10,000 years ago. It was traded along the Silk Road and spread across continents. But until recently, we weren't sure just how long we've been using marijuana for medicinal or therapeutic purposes.

In a 2019 study, researchers discovered chemical residues from the burning of cannabis plants during burial ceremonies at Jirzankal Cemetery in the Pamirs region of western China — 2,500 years ago. Cannabis stems and seeds have been found at various burial sites in Asia and Europe, but according to one theory, these ancient humans might have been smoking marijuana to communicate with those in the afterlife.

Cannabis has a lot of different uses

Pot and hemp — one can get you high, but the other has more uses.

In 2011, researchers at the University of Saskatchewan sequenced the genome of Cannabis sativa. They discovered that over thousands of years, humans selectively bred the plant into two strains: one for fibres and seeds, and one for medicine.

"The … analysis showed that the [synthase gene of THC's precursor, THCA], an essential enzyme in THCA production, is turned on in marijuana, but switched off in hemp," said Jon Page, a lead author of the study.

Hemp has been widely used for millennia. Besides rope and clothing, it's been used for everything from art canvases to sails to paper. In fact, one study suggests Easter Island's massive statues might have been "walked" into place using hemp ropes (and a lot of elbow grease).

More recently, hempcrete — a durable, lightweight composite reinforced with hemp — has been used in construction and can replace materials like drywall, insulation and siding.

'Stoned' might not mean impaired

There's a stereotype about marijuana users: they're lazy and mentally slower than non-users. But recent research suggests that in earlier studies on the impact of cannabis on cognition, subjects were affected by unfamiliar lab settings while using drugs.

UBC doctoral candidate Michelle St. Pierre wanted to get to the bottom of how weed can affect our brains. "Is it safe to get behind the wheel of a car?" she said in the documentary. "Scientists and the public are really interested in this."

St. Pierre had subjects perform a cognitive test and then asked them to get high as they normally would — on their own cannabis and in a familiar environment like their own home — and then had them perform another test so she could compare each person's ability while stoned and sober.

"We found that there was actually no difference in cognition between the sober condition and the stoned condition," she said. "I'm not saying cannabis doesn't cause any impact on cognition, but in regular near-daily users in a familiar environment, using cannabis in a way that's typical to them, we found not a lot of impairment if any."

Watch Science & Cannabis on The Nature of Things.