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Cannabis can reduce coronavirus infection? Study only said it might – and more research needed

“Cannabis can reduce coronavirus infection by more than 70 percent and may even treat it,” reads the headline of a 22 May 2020 article on the entertainment website Meeaw.

The article says Canadian scientists are researching cannabis as a possible “cure and treatment” for Covid-19. They examined 13 strains of cannabis with a high cannabidiol (CBD) content, it says, and found the plant “could have the potential to reduce infection” by up to 70%. 

The article has been viewed more than 2.7 million times on Facebook.

Cannabis, also known as marijuana, is a plant used as both a recreational and medicinal drug. CBD is an active ingredient in cannabis, with recognised therapeutic properties for treating conditions such as chronic pain and glaucoma, and managing nausea. 

Can cannabis reduce Covid-19 infection by 70%? We checked. 

Tissue model study suggest cannabis may reduce infection

The article refers to a study by researchers at Canada’s University of Lethbridge, published on 19 April. It’s titled “In Search of Preventative Strategies: Novel Anti- Inflammatory High-CBD Cannabis Sativa Extracts Modulate ACE2 Expression in COVID-19 Gateway Tissues”. 

The study tested 13 strains of cannabis that were high in CBD on artificial 3D models of human oral, airway and intestinal tissues. 

The research found that cannabis may decrease the angiotensin-converting enzyme 2, or AEC2 receptor. This is a protein on the surface of many cell types that the Covid-19 virus hooks into in order to enter the cells. 

“A number of [cannabis strains] have reduced the number of these receptors by 73 per cent, the chance of it getting in is much lower. If they can reduce the number of receptors, there’s much less chance of getting infected,” Dr Igor Kovalchuk, one of the researchers, reportedly said

Study limited, not peer-reviewed

But the study has not been peer-reviewed and has limitations. 

It was designed to be tested on 3D human tissue models. So tests on actual human bodies may not have the same results. The researchers say further research is needed into cannabis’s effectiveness in preventing coronavirus infection. 

And Prof Olga Kovalchuk, another researcher in the study, told CTV News that they had not tested the effects smoking cannabis has on the virus. 

The World Health Organization says no medicines have so far proven to be effective against Covid-19. “WHO does not recommend self-medication with any medicines, including antibiotics, as a prevention or cure for Covid-19.”

A Canadian study did find that cannabis may help prevent Covid-19. But the study has not been peer-reviewed and has limitations. The headline claim that cannabis can prevent coronavirus infection by more than 70% is false, making the article misleading. – Naledi Mashishi


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