Not necessarily licking (I mean, if you do it enough...), but this is a thing
Cool story with interesting social, cultural, and scientific interactions.
It may have been discredited outside of simple iron deficiency since I last read about it, but dietary studies on humans are notoriously difficult to do.
We used one of these with our daughter when she had a concerning iron deficiency. I'm not super sure if it helped since we also started feeding her more iron containing foods, but it didn't hurt 🤷♂️
This specific thing? Or just an iron chunk of some type?
The reason I know about this is the social aspect of trying to get people with endemic iron deficiency to use a supplement. If you're from the more industrialized would, I'd figure you'd take supplements that, while more expensive, may or may not be more effective.
A little cat iron puck was introduced in an Asian region with high iron-deficiecy in the poorer population, but nobody used it. So they did some research and changed it to resemble a fish instead and it took right off. Turns out the local culture considered fish lucky or something.
I actually teach my students about this strategy that the WHO employee in Micronesia in my sport nutrition class. It's less about the iron fish, and more about that dietary iron can come from cast iron cooking sources instead of supplementation (as the latter often causes digestive distress).
I saw someone do a demonstration once, they took a box of "iron-fortified" breakfast cereal, dumped it into a bowl, then ran a magnet through it. The magnet picked up some of the dust from the bottom of the bowl, that dust being the tiny iron particles that were added to the cereal to "fortify" it.
I put them in quotes as the word has no objective meaning as applied to a breakfast cereal, it's simply a marketing term. I did not intend to imply that ingested iron particles are not a valid source of iron for human biology.
You can get all the iron you need from vegetables and certain meat or even taking supplements. There's no need to go about eating rusty metal. In fact, my doctor has advised me not to eat nails. I have to trust what he says, he's printed out several impressive medical degrees.
US RDA age 19+ is 8 mg / day. Maybe if the iron bar is really rusty. Or, pills are cents a day. OR you could eat breakfast cereal or liver, lentils or spinach, Popeye.
Tetanus is a bacteria that lives in soil. It's only associated with rust because rust gives more surface area to allow dirt to accumulate on which bacteria can survive, and because iron objects are often sharp enough to pierce the skin. If you were cut with a gleaming razer that had just had soil smeared on it you'd have a good chance of contracting tetanus!
It's also because the bacterium in question is anaerobic, so it dies in an oxygen environment; rusting consumes oxygen, so it helps preserve the bacterium longer out of soil.
Edit: I had always been told this, but evidently it isn't true. The rust does not seem to have any effect on the bacterium that causes tetanus. Apologies for spreading misinformation.
I've read once that eating iron won't do anything for your iron intake, but for example sticking some rusty nails through an apple for a while and then eating the apple would.
When my wife was pregnant, a buddy gave her an old cast iron pan and told her to heat applesauce in it. Said it should help her iron deficiency, too bad we're to add to have remembered....
This is the reason prisoners are so healthy and full of vim and vitality. (right........)
UMMM I don't think you can get iron in your diet this way. First off, it's unlikely you're going to find a bar of pure iron anyway, since most metal bars are composites of many minerals.
Also, the iron has to specifically be in an ingestible form so the liver can process it. An iron bar ain't a lollipop. (maybe that should be a slogan for something).
When they say that cereal has added iron, they really mean that actual bits of iron are added (very tiny particles). You can use a magnet to pull some of them out, they're little iron filings.
So if you file the bar down first and eat the filings, MAYBE it would contribute to your iron intake. But - why not just grab some milk and eat the cereal instead?
Quick Google search suggests that using cast iron cookware increases your iron intake. I'd imagine the heat process has something to do with it though, so still incredulous that licking an iron bar would be effective, though I'm at a very minor maybe.
I saw that also but I have my doubts that you'd get much iron intake from cooking in iron pans. People used to get lead poisoning from using lead pots and pans, so - maybe it's possible. I'm not sure how much iron frying pans, for example, are pure iron.
Japan has traditional iron kettles (that are stupidly expensive) and they're often mentioned by doctors for use in people who have iron deficiency here. That or iron pans. They even make an iron ball to put in normal kettles and such, but that weirds me out a bit.