Don't reheat cooked spinach

[snopes]

Comment: Over here in Germany at least 50% of the population is CRAZY
about the following: People INSIST that reheating and ingesting already
cooked spinach will poison you, resulting in sickness and/or death. No
matter the amount consumed. Please help me put this rumor to rest, they
think I'm nuts to even attempt it.

[Mickey Blue]

Well.. Anechdotes and data and all that.. But (as a spinich lover) I have done this many many times, and not once have I even ended up with a stomach ache, muchless sickness and/or death..

-MB

[Hero_Mike]

Does that still count when the spinach is cooked in an Indian dish like saag paneer? By all accounts, I should have been dead 6 times over three weeks ago. There were a lot of leftovers...

Why would this be true of spinach? It can be eaten raw, as well as cooked. I could understand this to be possible for something that can't be eaten raw, but not as in this case.

[Morrigan]

I don't like spinach in the first place, so I definately don't see why someone would want to reheat it and eat it for a second meal.

Morrigan

[RobDBlackwolf]

Its -as I heard- essentially true but outdated.

Spinach that was repeatedly reheated (as it was cheap after the war and could be used over and over again, instead of having to cook something new) was slowly getting full of some heavy metal, which could lead to poisoning.

At least thats what I remember reading, and I'm currently at work, so I can't google the correct thing.

However, reheating it a few times is harmless. Just dont do it for several days in a row.

[RobDBlackwolf]

Alright, now I am home and found this one on a Wikipage:

Reheating spinach leftovers may cause the formation of poisonous compounds by certain bacteria that thrive on prepared nitrate-rich foods, such as spinach and many other green vegetables. These bacteria can convert the nitrates into nitrites, which may be especially harmful to infants younger than six months. The nitrate-converting enzymes produced by the bacteria can convert even more at elevated temperatures during the second heating. For older children and adults, small concentrations of nitrites are harmless, although formation of nitrosamine compounds from the nitrites could be of concern for adults as well.

[Don Enrico]

Originally Posted by snopes

Comment: Over here in Germany at least 50% of the population is CRAZY
about the following: People INSIST that reheating and ingesting already
cooked spinach will poison you, resulting in sickness and/or death. No
matter the amount consumed. Please help me put this rumor to rest, they
think I'm nuts to even attempt it.

The only UL about spinach I know about is that it is supposed to contain lots of healthy iron. From what I know, this goes back to a mistake made while analysing different vegetables some time in the 50s and carried on from there.

The "don't re-heat" story I know is about mushrooms.

Don "not that kind of mushrooms" Enrico

[llewtrah]

Wasn't the spinach misconception due to a decimal place in the wrong position making it seem 10 times healthier? or is that yet another UL?

[RealityChuck]

Spinach does have a pretty good amount of iron: raw spinach has 30% of the RDA per serving (4.5-7 mg).

The information about the amount of iron was known by the 1930s -- why do you think Popeye ate it?

[KathyB]

If you should not reheat cooked spinach, then why are frozen and canned spinach allowed ot be sold? Both are cooked. Here is an answer from a university professor

Spinach is one of the vegetables which may accumulate appreciable amounts of nitrate from the soil during the growing season. Nitrate is not harmful for our health. If raw spinach is cut and left for a long period of time or if cooked spinach is stored, nitrate is converted into toxic nitrite by bacterial activity. While the concentration of nitrite in re-heated spinach does not pose any problem for adults, babies and toddlers are much more sensitive to nitrite. Therefore, small children should not be fed cooked spinach that has been stored and reheated. Sterilized spinach filled in small glass jars as baby food should be used up directly after opening the jar.

Professor Felix Escher, Institut für Lebensmittel- und Ernährungswissenschaften, ETH-Zürich

Although spinach does have relatively high levels of iron, absorption of the iron is inhibited by oxalates also present in the spinach. But you still get some.

You can find claims that Popeye's creator used "spinach" as a eupemism for "marijuana." See Popeye the Sailor Man for instance.

[llewtrah]

Originally Posted by RealityChuck

Spinach does have a pretty good amount of iron: raw spinach has 30% of the RDA per serving (4.5-7 mg).

The information about the amount of iron was known by the 1930s -- why do you think Popeye ate it?

AIUI, the Popeye tradition was based on the miscalculation of iron as being something like 10 times the real value. Also, the iron in spinach is in a form that the human body can't easily use so its value was overstated in Popeye cartoons and was overstated in the 1930s.

What quantity of spinach has the 30% RDA? RDAs are useless unless the quantity is cited. Also, they don't always relate to the mineral being in a form we can extract from the foodstuff - the method used to measure the quantity of a mineral in a foodstuff is not the same as the method the human body uses to digest that foodstuff.

[Troberg]

AIUI, the Popeye tradition was based on the miscalculation of iron as being something like 10 times the real value.

On the other hand, Popeye is clear proof that spinach can cause deformities...

[alkalinelife421]

i thought cooked spinach in general was supposed to not be good for you. something about a chemical in it... oxylic acid ... being released or something. kinda like rhubarb. but who knows, maybe this is a UL too!

[llewtrah]

I see lots of cooked spinach dishes in the cook-chill and frozen food sections From the Wikipedia quote it seems the issue mainly relates to letting it stand after cooking so the bacteria can start acting. It would also depend on having the bacteria present, the quantity of bacteria and the temperature (since certain bacetria thrive at particular temperatures). Since you can't determine bacterial levels and growth rates in the normal kitchen, the "don't reheat cooked spinach" would seem to be a better-safe-than-sorry measure.

Much the same applies to reheating cooked rice that has been left to stand e.g. overnight (neither bacillus cereus food poisoning nor clostridium perfringens are fun and those are not experiences I wish to repeat), but if you freeze it as soon as it is cool enough it seems to be okay to reheat as you halt the bacterial growth.

[candy from strangers]

Originally Posted by alkalinelife421

i thought cooked spinach in general was supposed to not be good for you. something about a chemical in it... oxylic acid ... being released or something. kinda like rhubarb. but who knows, maybe this is a UL too!

Cooked rhubarb is supposed to be bad for people? I'd never heard that. What's the issue?

[Eddylizard]

Originally Posted by candy from strangers

Cooked rhubarb is supposed to be bad for people? I'd never heard that. What's the issue?

Rhubarb doesn't kill people, rhubarb and custard crumble kills people.

Rhubarb leaves contain poisonous substances, including oxalic acid which is a nephrotoxic and corrosive acid that is present in many plants. The LD50 (median lethal dose) for pure oxalic acid in rats is about 375 mg/kg body weight,[8] or about 25 g for a 65 kg (~140 lb) human. While the oxalic acid content of rhubarb leaves can vary, a typical value is about 0.5%,[9] so a rather unlikely 5 kg of the extremely sour leaves would have to be consumed to reach an LD50 dose of oxalic acid. Cooking the leaves with soda can make them more poisonous by producing soluble oxalates.[10] However, the leaves are believed to also contain an additional, unidentified toxin,[11] which might be an anthraquinone glycoside (also known as senna glycosides).[12] In the petioles, the amount of oxalic acid is much lower, only about 2-2.5% of the total acidity.[13]

[Mycroft]

Originally Posted by candy from strangers

Cooked rhubarb is supposed to be bad for people? I'd never heard that. What's the issue?

It is not the part of rhubarb which is eaten (the stalk) which is poisonous; it is the leaves (although rhubarb itself is a laxative; there is an annecdote that when Marco Polo arrived in China he and his crew were fed large quantities of rhubarb as the chinese thought their pale skin was a symptom of constipation)