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A doctor told me today that eating burnt toast along with tea is a remedy for poison. Apparently the burnt part of the toast acts like activated charcoal and adsorbs the poison you've ingested, and the tea has some kind of chemicals that mix with the poison and somehow neutralizes it.

There's also a website that has this info.

Toasted bread acts similarly to activated charcoal that is given at hospital settings for poisoning. Make the toast a little burned and pound the toast. Mix the powder to a glass of water and drink the solution immediately after possible ingestion of a contaminated food. This also contains activated carbon that is effective in absorbing the poison in the stomach before it is absorbed in the intestines.

This didn't make sense to me. I'd be inclined to believe that the tea has chemicals to neutralize poison, but when burnt toast is ingested, there's already a lot of saliva and the tea that engulfs it. How on earth is it going to adsorb anything at all in such a situation?

Sounds more like some witch doctor or a quack suggested this as a remedy, but the doc says that it's part of medical text books, and would obviously be reviewed and vetted. On asking him to verify it, he says he doesn't have the time to do that.

Is this true? Does eating burnt bread actually help adsorb and neutralize poison?

UPDATE: I showed the doctor your responses and this is his reply:

"...burnt toast, tea and wall scrapings make a universal antidote according to the text book but this is more of a historical importance and a misnomer cos it's not really universal.. It's just that if you've eaten something and have no option of medical treatment then in a worst case scenario this is Ur best shot to neutralize the poison as opposed to doing nothing.. it doesn't mean u eat this everytime u eat a poison with a hospital close by.. The toast acts as charcoal, tea for tannins and wall scrapings for lime or magnesia (I'm not sure) help in neutralizing certain poisons with varying efficacy.. In a hospital , u obviously wouldn't use this.. However, I have personally used 50g activated charcoal powder for a patient with digoxin poisoning.. it's not an antidote, but helps reduce biological burden of the poison. Saliva and water just course thru the activated charcoal.. poisons bind to it in a chemical reaction.. that's how it works.. Summary: ingested poison? Go to a hosp. Injested poison in an uninhabited room in the middle of the nowhere with no transport? Burn some bread, have tea, scrape the paint off the wall and eat them.. then pray :P"

ventsyv said he cross-posted on chemistry.stackexchange. I found it. This is the link.
I've posted a question specific to the doc's reply.

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  • Even if it does, would it counteract all the warnings not to eat burnt food (especially meats) (including toast) because of the acrylamide or PAHs in them?
    – user22865
    May 5, 2017 at 18:31
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    This is about eating burnt food only for the sake of neutralizing the poison. Eating burnt food regularly is a different matter and I've had quite a debate about it on cooking.stackexchange already: cooking.stackexchange.com/questions/77195/…
    – Nav
    May 5, 2017 at 18:34
  • Active Carbon neutralizes many things. I suppose the thinking here is that burnt food has a lot of free carbon. But as someone mentioned earlier, burnt food can contain things that are also poisonous.
    – Richard
    May 5, 2017 at 18:42
  • @ventsyv :-) I agree, but like the doc mentioned and like the quote in my question mentions "...charcoal that is given at hospital settings...". This is apparently medically accepted and practiced. I wonder why no doctor dared to question the logic of it. Do ask any doctor you personally know, and see what they say about it. I'd like one of them to actually spit on and pour water on activated charcoal and dip it into some poison in their lab to verify adsorption.
    – Nav
    May 5, 2017 at 18:57
  • I have cleared up a misconception in the question between burnt food (generally) and burnt toast. I'd like to see an answer clears up the misconception of mixing up the carbon in burnt toast and activated carbon, and the difference between absorption and adsorption.
    – Oddthinking ♦
    May 5, 2017 at 19:05

1 Answer 1

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Activated carbon is used to treat poisonings and overdoses following oral ingestion. Tablets or capsules of activated carbon are used in many countries as an over-the-counter drug to treat diarrhea, indigestion, and flatulence. However, it is ineffective for a number of poisonings including strong acids or alkali, cyanide, iron, lithium, arsenic, methanol, ethanol or ethylene glycol.

Source, emphasis mine.

Activated carbon is carbon produced from carbonaceous source materials such as nutshells, coconut husk, peat, wood, coir, lignite, coal, and petroleum pitch. It can be produced by one of the following processes: Physical activation: The source material is developed into activated carbons using hot gases. Air is then introduced to burn out the gasses, creating a graded, screened and de-dusted form of activated carbon. This is generally done by using one or a combination of the following processes: Carbonization: Material with carbon content is pyrolyzed at temperatures in the range 600–900 °C, usually in inert atmosphere with gases like argon or nitrogen

Source, emphasis mine.

Given the production process it appears that toast would not be a good source of activated carbon (otherwise they would just burn toast!). Even if it is, activated carbon is not effective for a number of poisons so it's pretty clear that burned toast would not be a good treatment for poisoning.

That being said, here are the answers from chemistry.stackexchange.com which expresses doubt on whether the toast would be a good source of activated charcoal.
There is also a mention that actual activated charcoal does seem to retain its adsorption properties even when submerged in some fluids. The person does not provide any references or confirmations though.

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    "Given the production process it appears that toast would not be a good source of activated carbon (otherwise they would just burn toast!)." <- this passage is not logically sound, we don't know why they don't just burn toast.
    – Sklivvz
    May 5, 2017 at 19:56
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    @Sklivvz: Presumably because the charcoal produced by those other processes is more effective than burned toast. But if bread is all you have, it's better than nothing. Likewise if you're some distance from doctor/hospital, eating toast or other charcoal immediately might be better than waiting.
    – jamesqf
    May 6, 2017 at 4:16
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    @Sklivvz: But carbon is not carbon. Swallowing your diamond ring would probably not help much, nor lumps of coal if that's what Santa left you :-) As I understand it, the benefit of charcoal comes from a very large surface area is created when everything but the carbon is driven off, making it very effective as an absorbent. See e.g. ncbi.nlm.nih.gov/pmc/articles/PMC1306980
    – jamesqf
    May 6, 2017 at 17:29
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    @Sklivvz: Yes, that's what I've been saying, that the answer - charcoal from burned toast isn't a good treatment for some poisonings, and that if charcoal was a good treatment, it'd be made from bread - is wrong. Obviously it's not the first choice if you're near a hospital with a poison control center, but what if you're not? Better to use what you might have at hand, rather than do nothing while the poison takes effect.
    – jamesqf
    May 6, 2017 at 23:06
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    @ventsyv Don't make it a community answer, just remove the assertion. That's what will happen if you make it a community answer anyway.
    – called2voyage
    May 8, 2017 at 18:20

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