A study performed at the University of Iowa has found “significantly higher THC” levels in people’s blood after drinking alcohol than if they hadn’t. Medical professionals and partiers alike had all suspected something along those lines, especially given alcohol’s notoriety for interacting with other drugs.
Alcohol can dangerously interact with many common pharmaceuticals, but its interaction with cannabis is less understood. If anything people say they just get the spins if they smoke after drinking too much, and some research shows that cannabis consumption makes people drink less alcohol.
Researchers gave 19 study participants either plain juice or a mixed-drink with alcohol, and let them vaporize cannabis using a Volcano Vaporizer by Storz & Bickel as they pleased. In the mean time researchers took the participants blood to observe the amounts of THC and its metabolites. The study carefully chose participants that were occasional smokers only, just a few times a week. They found that people had slightly higher levels of THC in their blood stream after vaporizing under the influence of alcohol, and subsequently higher levels of some THC-metabolites.
The scientists didn’t identify the exact cause of their finding, but did suggest a few ideas. “Alcohol-induced perfusion and distribution” may affect THC metabolism and absorption, and “acute alcohol increases cardiac output within 30 min, possibly leading to more rapid THC absorption during inhalation.”
Funded in part by the National Institute of Drug Abuse (NIDA), the Office of National Drug Control Policy (ONDCP) and the National Highway Traffic Safety Administration (NHTSA), all organizations that typically stand against cannabis, some of the findings might have to be taken with a grain of salt. Despite the potentially biased funding, researchers initially assumed that “alcohol would not substantially impact” cannabis in the body.
Their findings could lead to stricter policies regarding driving under the influence of cannabis, and especially combining alcohol and cannabis. Other research has shown increased motor impairment in people under the influence of both cannabis and alcohol than in either alone, and now this idea has solid ground to stand on.
But could the study be flawed? Aside from questions about its statistical analysis, the authors themselves pointed out an interesting weakness in their experimental method. Participants in the study were allowed to vaporize cannabis during a session as they pleased, and scientists found that different people consumed different amounts, likely due to personal preference; each individual had their preferred level of high. Therefore, people may have simply vaporized more when they were drunk than when they were sober, which would lead to higher blood levels of THC after a drug test. In their own words, “It is also possible that our higher blood cannabinoid Cmax reflects less careful cannabis self-titration after alcohol.”
Regardless of all the above, the study did in fact make some irrefutable breakthroughs regarding blood testing for cannabinoids. Further research into their findings may lead to a more accurate way of determining whether a driver suspected of being under the influence of marijuana, is in fact or not.
A regular cannabis consumer might have high levels of marijuana metabolites in the blood but remain perfectly sober enough to drive a few hours after smoking, but the science has not yet reached a way to prove this. Hopefully the science will further develop soon enough so sober and innocent stoners don’t get DUI’s.