Twelve elderly people accidentally ate marijuana cookies at a hemp workshop and ended up in the ER | Research

The takeaway

A mix-up at a hemp food workshop led 12 older adults to accidentally eat marijuana-laced cookies, causing symptoms within an hour and sending two to intensive care.

Read this if you want a real-world example of why hemp-marijuana confusion matters, especially for older adults.

12 hospitalized, 2 in intensive care after accidental marijuana cookie ingestion

What the researchers found

During a workshop on hemp's medicinal uses, attendees sampled various hemp food products. One participant brought cookies that actually contained marijuana rather than industrial hemp. About one hour after eating the cookies, people developed nausea, vomiting, dizziness, sleepiness, and difficulty walking.

Twelve people went to the emergency department. Two required intensive care admission due to central nervous system depression. All patients were managed with supportive care and discharged without lasting health consequences.

Why it matters

As hemp food products become more popular, the potential for confusion between hemp and marijuana increases, particularly among older adults who may be less familiar with cannabis products. This case illustrates the real-world consequences of that confusion and the particular vulnerability of elderly populations to unexpected THC exposure.

The numbers in context

12 people were treated in the ER. 2 were admitted to intensive care for CNS depression. Symptoms appeared approximately 1 hour after ingestion. All recovered without lasting effects.

How the study worked

Clinical case report documenting the event, patient presentations, and outcomes. Patients were evaluated in the emergency department with standard clinical assessment.

What this study cannot tell us

Single incident case report from one event. The exact THC content of the cookies was not reported. Individual patient details and dosing are limited. Cannot be generalized to predict outcomes of all accidental exposures.

How to read the evidence

Single case report of an accidental exposure incident. Useful for illustrating risks but cannot establish frequency or generalized outcomes.

When this study was published

Published in 2016. Accidental cannabis exposures, particularly among elderly populations, have become an increasing focus of public health attention.

The bigger picture

This case highlights a growing problem at the intersection of cannabis normalization and consumer confusion. As both hemp and marijuana products proliferate, the risk of accidental exposure increases, especially among populations unfamiliar with the differences between the two. Standardized labeling and education could help prevent such incidents.

Questions still open

How common are accidental cannabis exposures among older adults? Would standardized labeling of hemp versus marijuana products reduce these incidents? Are elderly individuals at higher risk of severe reactions to unexpected THC exposure?

Common questions

How are hemp cookies different from marijuana cookies?

Industrial hemp and marijuana are both Cannabis sativa, but hemp contains very low levels of THC (typically under 0.3%), while marijuana varieties can contain 15-30% THC. Hemp food products should not cause intoxication, but marijuana-infused edibles can produce strong psychoactive effects.

Why were older adults more affected?

Elderly individuals may be more sensitive to THC due to slower metabolism, lower body weight, no prior tolerance, and potential interactions with medications. Two of the twelve required intensive care, suggesting significant vulnerability in this population.

Read the original research

Accidental cannabis poisoning in the elderly.

Wiener klinische Wochenschrift, 128(Suppl 7), 548-552

View on PubMed ↗

Citation

Zupan Mežnar, Anja; Brvar, Miran; Kralj, Gregor; Kovačič, Dragan. (2016). Accidental cannabis poisoning in the elderly.. Wiener klinische Wochenschrift, 128(Suppl 7), 548-552.