'It’s a good news, bad news story': Cannabis researcher clears the air on COVID-19 and THC

Last updated: 13 เม.ย 2563  | 

PUBLISHED : 13 Apr 2020 - 10:34

“COVID-19 Patients Should Avoid THC,” is the headline of a news release published by Aurelius Data last month. It was reported on widely, including here at The GrowthOp. But when a doctor reached out to express some reservations about the conclusions of that interpretation of the cited studies, we contacted one of the world’s leading researchers of cannabis and the immune system, Norbert Kaminski, to find out more.

Kaminski, the director of the Institute for Integrative Toxicology at Michigan State University, prefaced his interview with The GrowthOp by saying he is not advocating that “people self-medicate with cannabis or cannabinoids” during the pandemic, but he says Aurelius is telling only part of the story. 

When it comes to people who have coronavirus, Kaminski says ingesting THC is a double-edged sword. 

As a professor in pharmacology and toxicology and a pioneering cannabis researcher, Kaminski has studied the effects of cannabis on the immune system since 1990. His lab at Michigan State was the first in the world to identify and characterize cannabinoid receptors within the immune system.

One of the studies cited in the review paper that informed the press released involved Kaminski and his colleagues experimenting with THC and the H1N1 influenza virus on mice. Two types of mice were used in the study, wild mice and genetically engineered mice without cannabinoid receptors. Both sets of mice were administered THC and the flu virus. Kaminski says the mice without cannabinoid receptors had far worse symptoms. 

“They were more gaunt, less mobile, there were significantly greater adverse effects,” Kaminski says. What that study showed was that THC was tempering the immune response. “The genetically engineered mice did not respond to THC and they did not respond to the molecules that are normally produced in the body that work through those receptors and that’s why those animals showed much more severe issues,” Kaminski explains. 

“It showed that there’s a balance. If you have a too severe immune response, the tissue damage that occurs can potentially be life-threatening and that’s what’s actually happening in coronavirus infected people, their immune system responds so well that it’s actually causing severe injury to their airways.”

Patients that end up in a severe respiratory symptomatic stage are at the highest risk of permanent lung damage. When coronavirus becomes that advanced, your own immune system becomes a danger as it goes into overdrive to fight off the invading virus. The longer and more aggressive that response, the more likely there will be damage to healthy lung tissue, or even death.

Dr. Randy Cron, a pediatric rheumatologist and professor at the University of Alabama, told the New York Times that once an invading virus is defeated, the immune system is hard-wired to shut off. But in some cases of coronavirus, the immune system keeps fighting, even when the virus is no longer a threat.

“It continues to release cytokines that keep the body on an exhausting full alert,” the article reads. “In their misguided bid to keep the body safe, these cytokines attack multiple organs including the lungs and liver, and may eventually lead to death. In these people, it’s their body’s response, rather than the virus, that ultimately causes harm.”

What Kaminiski’s team demonstrated was that when mice were infected with the H1N1 virus and then treated with THC, the ability to clear the virus was impaired. But — and this is the part that was overlooked by Aurelius Data, he says — the amount of damage that was caused in the lungs by the immune system to clear the pathogen was decreased.

“It’s a good news, bad news story,” Kaminski says. “The good news is that as the immune system gears up and destroys those cells it’s destroying the pathogen. The bad news is that if the response is too severe, the tissue damage that occurs can then compromise the ability of the lungs to do their job, which is primarily gas exchange.”

He also says that it’s important to keep in mind that the studies are on mice, and mice are not human. 

Julie Armstrong, the CEO and co-founder of Aurelius Data, says that she has heard the “mouse” criticism since publishing the release, but she stands by it. 

“I know you’re not a mouse, but viruses virus regardless of the host,” she says. “They can infect anything. Having the mouse as the host really doesn’t make a difference. It’s a mammal, we’re a mammal. The virus doesn’t care what the host is.”

Armstrong says CBD alone is “probably pretty safe, but we do know that THC is a problem.”

“Unless the symptoms that you’re treating with THC are more harmful than COVID, the suggestion still stands.”

Kaminski says the takeaway is that more clinical trials are needed. We simply do not know enough yet about coronavirus, and we’re still just scratching the surface when it comes to cannabis.

“I wouldn’t recommend anybody who has coronavirus take THC or smoke cannabis,” Kaminski says, before explaining that there is growing interest in treating severe cases of coronavirus with anti-inflammatory medications that could potentially decrease the severity of the immune system’s response. 

“It’s that balance between having a strong enough immune response to eliminate the pathogen but not so strong that basically the response ends up killing you because you have massive tissue injury,” he says. “I think there is promise for some of the anti-inflammatory properties of these cannabinoids for therapeutic use.”