How and Why Contaminated Spinach in Australia Can Cause Hallucinations

Delirium. Fever. Hallucinations. Not what you’d expect when adding spinach to a salad, but these are among the alarming symptoms dozens of Australians have experienced after consuming what are believed to be contaminated batches of the vegetable.

More than 100 people have reported symptoms, including 54 who sought medical help, after eating spinach sprouts that authorities believe to be contaminated. Four supermarket chains recalled products containing the suspected spinach.

Officials said the spinach caused possible toxic reactions, with those affected showing symptoms including blurred vision and rapid heartbeat.

Some Australians took to social media to jokingly ask how they could get hallucinogenic spinach. “I’ve never been so interested in salad,” said one Twitter user.

But officials stressed that the symptoms are not pleasant. “They can’t see straight; they’re confused; they’re hallucinating,” says Darren Roberts, medical director of the New South Wales Poison Information Center, referring to the victims in a local TV interview. “And we’re talking about scary hallucinations; it’s not fun at all.”

The company producing Riviera Farms, in the state of Victoria, said it believed that the product was contaminated with a weed.

What herb could make spinach hallucinogenic? The Victoria State Department of Health said the symptoms suggested “anticholinergic syndrome”, a type of poisoning caused primarily by plants in the Solanaceae family, which includes belladonna and mandrake root.

Plants and anticholinergic drugs inhibit the production of a chemical called acetylcholine, linked to memory, thinking and the visual system, according to Dominic ffytche, professor of visual psychiatry at King’s College London who specializes in visual hallucinations — he uses a lower case in the last name.

Acetylcholine can also be lost naturally and is linked to Alzheimer’s disease, types of dementia and other neurodegenerative diseases.

Hallucinations caused by acetylcholine suppression or loss tend to be formed, ffytche says, and are concrete and recognizable, often taking the form of people, objects and landscapes. This is different from “unformed” hallucinations, in which people can see shapes, patterns, and colors.

In addition, hallucinations caused by a lack of acetylcholine are linked to the memory system, so they tend to involve people that the individual knows or recognizes. “It could be deceased relatives or people who are vaguely familiar to them in some way.”

Those experiencing more extreme symptoms may have difficulty determining what is real. “Once you lose the understanding that they are hallucinations, they tend to become distressing. You get sucked into the story where something bad is happening and people are trying to hurt or harm you in some way.”

Exposure to anticholinergic plants can have serious effects, but it is rarely fatal. It’s also relatively unusual: In 2020, there were 856 cases of exposure in the US, none of which resulted in death, according to the American Association of Poison Control Centers.