Could marijuana make you sick? Fungal infections raise concerns

• Fungal infections on marijuana can produce dangerous toxins, according to a new study.
• Other common, and federally legal, crops have been bred to resist fungi.
• Scientists still have more questions than answers about the dangers of marijuana use.

Can marijuana make you sick?

After Tuesday’s vote in Ohio, nearly half of U.S. states have legalized marijuana for recreational and medical use. Now a new study warns that fungal infections on cannabis could cause illnesses.

“The people who should be worried about it are people who are immunocompromised. But that includes even people who are diabetic, which is a large segment of our population,” said Kimberly Gwinn, a professor of entomology and plant pathology at the University of Tennessee Institute of Agriculture. Gwinn is the lead author of the study, published in Frontiers in Microbiology.

The fungi that infect marijuana, like Aspergillus or Fusarium, and the dangerous toxins they produce are well known to scientists. The same fungi are found on other grains and vegetables. But well-established crops, unlike marijuana, have been bred to resist fungi.

The process used to create marijuana edibles, which concentrates the psychoactive substance THC, could also concentrate mycotoxins, the toxins produced by fungi.

Cannabis users sometimes experience uncontrolled vomiting, known as cannabinoid hyperemesis syndrome. Gwinn suspects the condition could be caused by a mycotoxin produced by a Fusarium fungus.

“The mycotoxin’s common name is ‘vomit toxin,’” she said.

Hemp and CBD also at risk

Gwinn came to the study of marijuana from her work on hemp, which was legalized for commercial production in the U.S. by the 2018 Farm Bill.

Hemp, which is used for everything from CBD gummies to environmentally friendly building materials, is the same plant as marijuana. Hemp by law, however, can be no more than .3% THC.

Marijuana remains illegal in Tennessee. For her research, Gwinn relied on the work of colleagues in states and other countries where the drug is legal.

More:Ohio just passed Issue 2, legalizing recreational marijuana. What Tennessee residents should know.

The same fungi that were found on marijuana plants can infect hemp, which is often eaten by humans as seed and flour.

Gwinn is particularly concerned about the growing use of hemp to feed animals, because animals such as chickens and pigs are particularly sensitive to these toxins.

Who will regulate marijuana?

Federal regulations control toxins in other crops. But as long as marijuana remains illegal at the federal level, any regulations or monitoring will have to come from the states. And currently those regulations vary widely.

Marijuana used by patients with compromised immune systems, Gwinn recommended, should be irradiated to kill live fungi and subject to closer scrutiny for toxins. Recreational marijuana users often reject irradiation as an “unnatural” process, although Gwinn said it has no effect on the drug.

Scientists have more questions than answers about the dangers of fungi and marijuana. Gwinn hopes with further research we will eventually know the crop as well as we do wheat or soy.

“We wrote this paper understanding that we were going to cause a stir,” Gwinn said. “This is something that people hadn’t really thought that much about.”

Todd A. Price is a regional reporter in the South for the USA TODAY Network. He can be reached at [email protected].