We’ve all heard of death by chocolate, but how would you feel about dying from too much soy sauce? It may sound like a bizarre fate – but in fact, it’s not just possible, but surprisingly easy.
When it comes to versatile foods, there’s not much that can come close to the humble soybean. Without this diminutive legume, we wouldn’t have tofu or soy milk; we’d be out miso, natto, and tempeh; we would have neither half the vegetarian and vegan options that line our supermarket shelves nor half the non-vegetarian options; and, of course, we wouldn’t be able to eat the soybeans themselves.
We’d also have to forego soy sauce, the deliciously salty and umami condiment that was first invented more than two millennia ago and has since conquered just about the entire world. Like the beans it gave its name to, this sauce is crazy versatile: it can be added directly to recipes as an ingredient; added on top of rice, noodles, or sushi; in some places, it’s even an ice cream flavor.
But if none of that appeals, you can always just drink it neat and put yourself straight into a coma.
And that’s if you’re lucky. Soy sauce is surprisingly deadly for a condiment you almost certainly have in your kitchen cupboards right now: there are many, many reports of people overdosing on saturated salt solutions, and in fact in its native East Asia it’s not unheard of for people to die by suicide by soy sauce.
The reason soy sauce is so toxic is pretty much the same reason it’s so tasty: its insane salt content. Just one tablespoon of the stuff contains more than a third of your recommended daily intake of sodium, making it easy to get an unhealthy dose just from seasoning your ramen too enthusiastically.
Push the soy sauce limit too far, though, and you’re heading towards disaster. Take the case of one 19-year-old man who, in 2013, downed a quart of the stuff – that’s almost a full liter, for the metrically-minded among you – only to end up comatose in the emergency room.
“He didn't respond to any of the stimuli that we gave him,” emergency medical physician David J Carlberg, who treated the soy sauce casualty at the University of Virginia Medical Center in Charlottesville, told NBC at the time.
“He had some clonus, which is just elevated reflexes,” Carlberg explained. “Basically the nervous system wasn't working very well.”
Too much salt in the blood causes a condition called hypernatremia, in which water moves out of the body’s tissues in an attempt to equalize salt levels between them and the blood. It’s very dangerous: not only can it cause fatal fluid buildups in places like the lungs, but as water leaves the brain, the organ can shrink and bleed, causing neurological symptoms like seizures and unconsciousness.
Lucky for the patient, he was taken to the ER and treated pretty quickly – within four hours of the condiment chugging, he was being fed 6 liters (1.5 gallons) of sugary fluid via IV in an attempt to lower his sodium levels. It worked fast: after peeing more than 4 liters (1 gallon) in an hour, the patient’s sodium levels returned to normal – although it would be another three days before his consciousness and mental status returned to normal.
Somehow, this patient escaped unscathed from the experience – although the case report noted that his blood sodium level as measured at the Medical Center was the highest ever seen in an adult that hadn’t either died or suffered lasting neurological damage because of it. By rights, he shouldn’t have been so lucky: a fatal dose of sodium can occur at levels as low as 0.5 to 1 gram (0.02 to 0.04 ounces) of salt per kilogram of body weight, which is less than half the amount he ingested in this college dare gone wrong.
So, next time you feel like adding just a bit more soy sauce than the recipe suggests to your bowl of noodles, remember: don’t go overboard. It might be a tasty addition to your meal – or even your dessert – but it’s probably not worth a trip to the emergency room.