By / May 21, 2020

Mold-containing cannabis could pose a serious threat to patients health

Like other plants, cannabis may also develop mold. Research has already shown that consumption of cannabis with a too high concentration of certain molds can lead to contamination with dangerous fungal infections – especially in cases of weakened immune systems.

A new study by the CDC, the Center for Disease Control in the United States tried to estimate, by analyzing the medical data of over 21.5 million people, the prevalence of infection in people who consume mold-containing cannabis.

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Mold-containing cannabis and its effects on medical cannabis consumers

“Cannabis may contain fungal pathogens that cause serious and even fatal diseases in immunocompromised patients such as cancer patients, AIDS patients, and patients who have undergone organ transplantation and use cannabis to reduce pain, nausea, and to help regain their appetite,” the researchers wrote.

“As of today, it is unknown how many people are contaminated with fungal infections as a result of cannabis consumption. However, this is worrying given the fact that more and more countries are allowing cannabis for medical and recreational purposes,” they added.

“We used 2016 medical insurance claims data to estimate the rate of fungal infections among people using cannabis and non-people and to compare the two groups.”

The results of the study showed that 0.08% of cannabis consumers sampled were treated in 2016 because of some sort of fungal infection, compared to 0.03% of those who do not consume cannabis. After adjusting for control of intervening variables (for example, cannabis consumers tended to be younger and more consumed tobacco), it was found that cannabis consumers were on average 3.5 times more likely to seek treatment because of these diseases.

Cannabis consumers also had a 3.5-fold (0.03%) rate of mold-related infections compared to the rest of the sample (0.01%), and 2.2% (0.04%) of other fungal infections compared to the rest of the sample (0.02%).

The results of the analysis showed that 43% of cannabis consumers who developed a fungal infection in 2016 were indeed defined in their medical records as immunocompromised patients (before they became infected). The most common fungal infection among cannabis consumers (about 43% of all infections) is aspergillosis.

Aspergillosis is an infection caused by the asparagus mold, one of the most common types of mold in cannabis in the world. The asparagus has also been found in medical cannabis in Israel, and this year has been identified by researchers from the Volcanic Institute as one of the most common types of mold.

Researchers speculate that the vast majority of them were infected by smoking, as the infections they saw were most commonly infected by inhalation. Accordingly, they recommend immunocompromised patients, especially patients undergoing organ transplantation, to avoid smoking cannabis (it is unknown whether vaporization is preferable in this regard).

A maximum mold level in cannabis should be implemented

The infections mentioned in the CDC study are not caused by cannabis itself, of course, but by the mold spores that develop on the plant during growth and storage. Cannabis consumption with little mold is usually not dangerous for people with a healthy immune system – but it can be life-threatening for patients with a weakened immune system.

The higher the mold concentration in cannabis – the greater the risk of immunocompromised patients from consuming it. For this reason, countries around the world have established regulations that define the maximum concentration of mold permitted in medical cannabis. The Israeli standard permits maximum mold and yeast concentration of 2,000 CFU per gram of inflorescence, the American standard allows up to 1,000 CFU per gram, and the Dutch standard allows up to 100 CFU per gram.

It is well-known that the vast majority of medical cannabis growers in Israel and around the world do not live up to this threshold, so they transmit cannabis to radiation.

If even the medical cannabis grown under strict conditions and strict supervision contains too much mold – what does that say about the illegal cannabis sold on the black market? Unfortunately, there is no such reliable data on illegal cannabis in Israel, but there is a study that has investigated the concentrations of cannabis sold in coffee shops in the Netherlands.

The average mold concentration measured in 11 different cannabis products purchased at a Coffee Shop in the Netherlands in 2006 was about 54,000 CFU, which is 27 times more than the maximum mold concentration allowed in medical cannabis in Israel and 540 times that of medical cannabis in the Netherlands. In one of these samples, the concentration of mold and yeast was 480,000 CFU!

At the moment, when quite a few medical cannabis patients, some of whom are immunocompromised, are forced to buy their cannabis on the black market, these data are certainly more worrying and stressing than ever before. It is very important for these patients to have legal and clean cannabis access through lab testing and concentration of known and limited doses.


(Featured image by Add Weed via Unsplash)

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