The death of a California man who was being treated for cancer is being blamed on a rare fungal infection.
According to a CBS report, the man may have been exposed to the fungus while using contaminated medical marijuana.
Following his death, researchers tested 20 medical marijuana samples from dispensaries around Northern California.
A study from the University of California, Davis, found that most were contaminated with unsafe bacteria and fungi.
Many of them can cause serious lung infections.
Fungi included cryptococcus, mucor, and aspergillus.
Bacteria included E. coli, Klebsiella pneumonia, and Acinetobacter baumannii.
The findings are published in Clinical Microbiology and Infection.
Researchers caution people with cancer
The U.C. Davis researchers warn that smoking, vaping, or inhaling aerosolized marijuana could be dangerous to some people with serious ailments.
People with leukemia, lymphoma, AIDS, or others undergoing immune suppressing therapies are at particular risk.
They also advise against using marijuana in baked goods. At least for now.
They theorize that cooking would destroy the bacteria and fungi, but they have not seen experimental evidence of this.
“Patients with impaired immune systems are routinely advised to avoid exposure to plants and certain raw foods because of the risk of infection from soil-dwelling organisms,” Dr. George Thompson III, said in a press release.
Thompson is an associate professor of clinical medicine at U.C. Davis in the Department of Medical Microbiology and Immunology. He was also a lead author of the study.
“But at the same time, they are increasingly turning to medical marijuana to help them with symptom control,” he continued. “Because microorganisms known to cause serious infections in immunocompromised patients were found to be common on marijuana, we strongly advise patients to avoid it.”
According to the study’s authors, marijuana from legal dispensaries isn’t necessarily safe. That’s because there’s no federal regulation for quality.
Also, doctors may not link an infection to medical marijuana.
How marijuana helps people with cancer
“Medical marijuana seems to be potentially helpful for many cancer problems,” said medical oncologist Dr. Jack F. Jacoub.
In an interview with Healthline, Jacoub said medical marijuana can help with numbness and tingling (neuropathy), nausea, and loss of appetite.
“It can also help with chronic pain syndromes related to the disease or treatment,” continued Jacoub, who is director of thoracic oncology at MemorialCare Cancer Institute at Orange Coast Memorial Medical Center in Southern California.
Jacoub said these are tough symptoms to control. And he’s seen better-than-expected results.
“Other prescription medications have a role. Without a doubt. But you have to work with the side effects. Some patients really respond to medical marijuana,” he said.
Medical marijuana can be delivered in many ways, including smoking, inhaling, eating, and even in oil. Marijuana also has some side effects, including the “high.”
“I’m quite convinced we’re only beginning to understand its use in cancer patients,” said Jacoub. “Some people come back after trying many things and medical marijuana is the one thing that helped. There’s definitely a group of people that benefit. You’d have to be shortsighted not to see that.”
What cancer patients need to know
Not all cancers are alike.
Jacoub explained that in general, cancer develops due to a preexisting degree of immune system incompetence. Some cancers are tightly associated with a compromised immune system. These include leukemias and lymphomas.
In addition, some chemotherapy drugs will further suppress the immune system.
“Patients are notified of this. Infection can be severe and life-threatening. They’re told what to avoid and what to report to their physician,” said Jacoub.
They’re advised not to eat fresh fruits and vegetables without cooking or steaming. Some can’t even have fresh plants in their rooms.
These people should be very careful.
“Please discuss this with a physician experienced in dealing with compromised immune systems,” Jacoub suggested. “They will understand the nuances and can advise you. Don’t take it upon yourself.”
If you have cancer and want to try medical marijuana, Jacoub has a few other suggestions.
First, decide what symptoms you need help with that you’re not getting help with now.
Second, visit a dispensary that has an abundance of experience dealing with your condition. Ask about the potential side effects of various products.
“The route probably most concerning for infection like the one reported is smoking,” said Jacoub. “Warning signs of infection are a nagging cough and phlegm. Some people have chest pain. But the biggest one is fever.”
Regulations vary from state to state and aren’t always clear.
“There should be tighter regulations. Without them, it’s still a risk, even when you buy from a dispensary. But it’s probably safer than buying on the street. Hopefully, that part of the market will ultimately disappear,” said Jacoub.
There’s limited data on medical marijuana use.
“We don’t have large clinical trials. But there have been some really interesting outcomes in patients who report improvements in symptoms,” he said.
Making informed decisions
“Cannabis is an agricultural product and it is unreasonable to expect that it would be free of bacteria and fungus that are found routinely in soil,” said cannabis therapeutics expert Dr. Jordan Tishler of Inhale MD in Massachusetts.
In an email to Healthline, Tishler explained that it’s not well understood if any of those pathogens routinely survive smoking, vaporizing, or cooking.
“Best evidence to date suggests that temperatures around 350 degrees Fahrenheit and higher will kill these agents. What isn’t clear is whether smoking and vaporizing achieve these temperatures in a thorough enough manner to kill whatever’s in there. What we need, and do not yet have, is testing of the smoke/vapor output to viable organisms,” said Tishler.
Tishler makes the point that marijuana use by people with cancer is not new. It’s been going on for decades, if not longer. Even so, it’s rare that an illness is traced back to medical marijuana.
“It could be countered that we haven’t been looking for such. But if it were enough of a hazard, I would suspect we would have noticed,” he said.
Tishler said there’s no doubt we need more research. But he believes there’s adequate data to make informed decisions.
“The key is to have a detailed and thorough discussion of the risks and benefits of cannabis therapy with a caring, educated cannabis specialist in conjunction with the rest of your medical team,” he advised.