A CDC study found people who smoked cannabis had a slightly higher risk of fungal infections than those who didn’t
A government report warns that cannabis could cause deadly infections, not from the smoke it creates, but from fungus and mold that grow on the plant’s flowers.
The study, published on May 13 by the US Centers for Disease Control and Prevention, builds on previous research in California and Colorado that found legal marijuana was contaminated with pesticides and mold, and could pose a risk to people prescribed marijuana for medical conditions.
In the new report, CDC researchers looked at 2016 health data from around 27 million people in an IBM database and scanned it to see if there was a link between cannabis use and fungal infections.
They found 40 of the 53,000 people who used cannabis developed a fungal infection in 2016 — roughly 0.07% of them. By comparison 6,294 of the 21 million non-cannabis users contracting a fungal infection (or, 0.02%). The likelihood was extremely low across the board, but the CDC issued a report on their findings, warning that, proportionally, fungal infections were more 3.5 times common among cannabis users.
The researchers said that marginally increased risk is still cause for concern because of the potentially deadly nature of fungal and mold infections, and existing evidence that cannabis is susceptible to fungus growth.
“In this large commercially insured population in the United States, cannabis use was associated
with a higher prevalence of certain fungal infections,” the researchers wrote.
“Although these infections were uncommon, they can result in substantial illness and even death, particularly in immunocompromised persons.”
Those who used cannabis and got fungal infections tended to be young and immunocompromised
Overall, cannabis users were more likely to report having fungal infections than the non-cannabis user population.
The researchers said this could be because 60% of the cannabis users they looked at smoked it regularly, which could make them more susceptible to illness in general.
Indeed, 43% of cannabis users who had fungal infections were immunocompromised, and 40% of cannabis users who had fungal infections were hospitalized upon their diagnosis because of the severity of their conditions.
Fungal infections can range from mild to severe, but for immunocompromised people who have HIV, underwent chemotherapy, or have other conditions that weaken their immune response, the infections can be life-threatening, according to the CDC.
For normally healthy people, a fungal infection can lead to a rash, allergies, or asthma, but in more severe instances, it can cause pneumonia, meningitis, and bloodstream infections.
They also found that cannabis users who had fungal infections tended to be younger than those who didn’t use cannabis but had fungal infections. The median age for a cannabis user with a fungal infection was 41.5, but for non-smokers it was 56.
Cannabis plants can be susceptible to fungus and mold
There were caveats to the study. They relied on self-reported claims about cannabis use, which could have skewed their findings.
The researchers also couldn’t determine the source of the subjects’ fungal infections, so it’s impossible to say if cannabis use caused them.
There’s no federal institution that requires cannabis dispensaries or growers to test their cannabis, so companies tend to create their own protocols, Business Insider previously reported. Often, they use third-party labs to test their cannabis batches for fungus, mold, and pesticides.
You can ask for more information about your cannabis, or abstain from using it to protect your health
If people want to continue using cannabis but worry about fungus and mold content, they should ask budtenders at dispensaries to provide testing documentation, Donald Land, chief scientific consultant at cannabis and tech firm Steep Hill, previously told Business Insider.
They can compare the document with a state’s guidance on threshold levels, like the one Oregon provides its residents.
The researchers who did the study suggested people who are immunocompromised reconsider smoking cannabis to protect their health.
People who use cannabis and are immunocompromised could be at risk for deadly complications like pneumonia, according to the CDC-backed study.