Truth is, we don't know yet …

A recent study by the University of Pernambuco in Brazil found that smoking marijuana with added terpenes may cause serious kidney damage in users.

Terpenes, the latest ingredient to polarize the cannabis community, is the essential oil of a plant that gives it unique tastes and smells. Marijuana, pine trees, oranges, apples, limes and lemons all have their own terpene palate that creates their one-of-a-kind tastes. They're naturally occurring, but that doesn’t mean they're necessarily healthy — example, menthol is a terpene.

Today, with marijuana concentrates (dab’s, oil, shatter) growing in popularity, the laboratories extracting the concentrates are also adding terpenes back in to the oil to make it taste better, but with little research into terpenes and marijuana, it's impossible to know how the two react when smoked together. 

In order to study the issue, the researchers at the University of Pernambuco forced lab rats to inhale weed mixed with the terpene Beta Carotene (BC).

BC is found naturally in carrots, yellow and orange fruits, and also green vegetables. It is already known that high levels of BC mixed with cigarette smoke can cause lung cancer, but how does mixing in weed make it bad?

The researchers found that when smoked, the molecules in pot break down the BC molecule and turn it toxic, leading to kidney damage in the exposed rats. This change in structure is called degradation, and it can be very uncontrollable.

Even more troubling is that the degradation begins only when the oil is smoked, so none of the testing currently conducted in Colorado picks up on these toxins.

Colorado’s weed is so far only tested on a state level, meaning the federal government has no regulation over the pot reaching consumers. As it stands, there's not a whole lot of regulating the regulators. 

Thomas Mohan, a detective for the Colorado Marijuana Enforcement Division, says the government agreed not to take action against legal marijuana as long as pot isn’t sold to other states, minors aren’t getting ahold of it, and the money made isn’t being laundered or sent to drug cartels.

And even though Colorado has strict guidelines on what can and cannot be in retail marijuana, Mohan adds that concentrates are only required to be tested for potency (THC and CBD concentrations), microbials and extraction agents. Not terpenes.

The state doesn’t even require mandatory testing of pesticides for medicinal marijuana (that is until October 2016 — some 2 1/2 years after recreational legalization went into effect).

Yet some extraction companies, like Clear Concentrates, post the results of their toxicity screenings online regardless. However, these tests don't account for individual terpenes, so it's hard to tell if concentrates are putting you at risk.

In 2011, Colorado’s Department of Revenue estimated there are 600,000 marijuana users in the state of Colorado alone, and that was three years before cannabis became recreational. With weed use on the rise, more research needs (and is being done) to help keep Colorado consumers safe and prevent toxic marijuana from hitting the shelves.

We're not saying to immediately extinguish your favorite pastime, but consumers should be aware of the potential risks when going down to a local dispensary for strains with added terpenes. The industry is young, and so are the studies associated with it. 

The truth is, nobody really knows if terpenes are bad for human consumption, one study is just that, one study — but it's always best to know the temperature of the water before jumping into the deep end.