Adding iodine to salt played a role in cognitive improvements: research (2013)

https://www.discovermagazine.com/health/how-adding-iodine-to-salt-boosted-americans-iq

by 1970-01-01 • 1 year ago

229 152 1 year ago

burnte• 1 year ago

Public health generally works!

sitkack2• 1 year ago

Iodine deficiency today is the leading cause of preventable mental retardation in the world. It’s estimated that nearly one-third of the world’s population has a diet with too little iodine in it, and the problem isn’t limited to developing countries — perhaps one-fifth of those cases are in Europe (pdf), where iodized salt is still not the norm.

https://web.archive.org/web/20200820212020/https://www.who.i...

The Recommended Dietary Allowance (RDA) for iodine is between 220 micrograms (mcg) and 290 mcg in pregnancy, and 290 mcg when breastfeeding. [1]

Iodine affects the thyroid which produces hormones that regulate how the brain develops in the womb. If these T3/T4 hormones aren't strong enough, brain cells don't get into the right places.

Apparently Iodine intake needs to be 50% higher than the normal healthy level during pregnancy (and higher during breast feeding). Taking prenatal vitamins now in case I get pregnant.

[1] https://www.ncbi.nlm.nih.gov/books/NBK582771/

[2] https://www.phind.com/search?cache=l34zoyrwfc8ocb3vcodcsc46

So when neurons form in the brain, they are born in a nursery and then migrate to their final destination. Here is a movie showing this, https://www.youtube.com/watch?v=OMYHx7dRe8g

Mapping Postnatal Neuronal Migration: A Late Path to Neurodevelopmental Disorders https://www.youtube.com/watch?v=E4FZiv-rtTU

Neurogenesis in the mammalian brain https://www.youtube.com/watch?v=B2RINOAeONw

ed312• 1 year ago

This was both a new topic to me and a remarkably succinct (and well-cited) comment. Did you happen to do this research independently or do you reference a more comprehensive source?

gopalv2• 1 year ago

Burger King continued to use iodized salt consistently, while McDonalds, Wendys etc have switched to flakier salts for their fries which cuts total sodium overall by being flatter instead of grainy, but without any iodine added to it.

The downward trend in fast food began in the 70s, once sodium was seen as bad, so more salty tasting thin crystals were preferred.

[1] https://pubmed.ncbi.nlm.nih.gov/20634172/ (on researchgate)

erikpukinskis• 1 year ago

I also prefer cooking with the flakier stuff because I can grab a pinch of it and sprinkle it in a controlled way.

I try to use iodized salt when it’s convenient: when salting pasta water, in baking, etc… but I wonder if my family is getting enough.

dkarl• 1 year ago

When my wife's doctor recommended more iodine in her diet, I was surprised how hard it was to find iodized flaky salt. I only found one brand I could order, and it was extremely expensive and didn't have a great texture for cooking with. I keep iodized table salt around and sometimes use it for salting soup, stock, or pasta water, but 99% of the time I reach for plain old Morton kosher salt.

FriedPickles• 1 year ago

Hmm, why don't they make iodized flaky salt?

gopalv2• 1 year ago

why don't they make iodized flaky salt?

They'll figure out a way eventually, but it is definitely harder.

It is always easy to grow something uniform as a pure crystal, without fault lines on them causing crumbling.

As a kid who spent a lot of time with chemistry, it used to fascinate me that you can crystallize out a clean salt crystal out of a mix of potassium permanganate and salt, the salt grain will grow pretty much pure salt on it without a hint of purple (also burned my nose skin off collecting chlorine from the exercise, talk to your local chemistry teacher and find out why).

I never succeeded in making a colored salt transparent crystal.

ufo3• 1 year ago

I think it's a United States thing. There are other countries where all salt meant for human consumption must be iodized.

ak2173• 1 year ago

downward trend ... sodium was seen as bad

Excess sodium intake is associated with cardiovascular disease and heart failure. Salt is also an opportunistic carrier for iodine supplementation. So to call it good or bad, you'd need to either come up with an epidemiological study of the two diseases relative to each other, or maybe propose an alternative carrier for the iodine supplementation.

simondotau• 1 year ago

Excess sodium intake is associated with cardiovascular disease and heart failure.

The evidence for this is poor, and there is some evidence to the contrary.[0] Right now it is difficult to assert that there's anything more than a correlation, possibly because many popular high salt food choices could be bad for reasons other than sodium (e.g. fast food staples). In recent decades, widespread success of anti-salt messaging means that lower salt intake is now highly correlated with eating a healthy diet.

There's no first-order harm in a low salt diet, but there may be some second-order concerns. For example, when food manufacturers are pushed to reduce salt, their arsenal for achieving hyperpalatability becomes narrowed to objectively worse things like sugar and refined seed oils.

[0] "The field of heart failure has evolved [...] There is now substantial randomized trial data to indicate that dietary sodium restriction does not provide the reduction in clinical events with accepted heterogeneity in the clinical trial results." https://pubmed.ncbi.nlm.nih.gov/38215917/ (2024)

nradov• 1 year ago

The issue with sodium intake is not the quantity but rather the osmolality.

https://peterattiamd.com/rickjohnson/

ThrustVectoring• 1 year ago

Saltier tasting salt is likely counterproductive, IMO. People aren't born knowing how much salt taste corresponds to how much salt consumption, so that gets tuned by persistent salt deficits causing upregulation of salty food desire. In other words, homeostatic feedback causes salt consumption to stay about the same by increased consumption of salty-tasting processed food.

kijiki• 1 year ago

In other words, homeostatic feedback causes salt consumption to stay about the same by increased consumption of salty-tasting processed food.

I'd imagine that McDonalds/Wendys/etc don't view that as a bad thing...

tasty_freeze• 1 year ago

While I was growing up, my family put so much salt on everything, even before tasting it. About once a month during the summer months my folks would surprise us by picking up pizza (with 8 growing kids, it was a lot of pizza). The top would be flopped open on the boxes, and then mom would start shaking the salt, and shaking, and shaking, and wouldn't stop until you could see a layer. We were all so used it that non-salty pizza was drab, just as you state.

I finally kicked the habit when I went to college. There were no salt shakers out on the tables. After the first semester I went home and nearly choked on the level of salt on the food.

thatcat• 1 year ago

i wonder why when you can simply add potassium salt to make it taste saltier without sodium

jeffbee2• 1 year ago

Iodized salt, sanitary sewers, and shoes are the showcase achievements of public health, aside from vaccines and whatnot that people associate with progress in medicine.

fodkodrasz• 1 year ago

I agree, but not forget washing hands and using antiseptics where it makes sense.

shortrounddev24• 1 year ago

Fluoridated water too

PKop3• 1 year ago

Nope. Trivial benefit while marginally lowering IQ.

Fluoride Exposure and Children’s IQ Scores A Systematic Review and Meta-Analysis [0]

[0] https://jamanetwork.com/journals/jamapediatrics/fullarticle/...

ramon156• 1 year ago

Most european countries would like to disagree

timewizard• 1 year ago

I can get non-iodized salt, use a septic tank, not wear shoes, and skip vaccines (and home school) if I so choose to. I can't choose to get unfloridated water from the public system. It's a little odd that a public health intervention has been prescribed to everyone en masse.

sysworld2• 1 year ago

I think that's a bold statement. I'd say the jury is still out on that (especially for pregnant women and babies).

Though I will agree with fluoridated toothpaste. I would rather the govt gives out fluoride toothpaste to people, then force everyone to drink it, which research is still ongoing. Or offer discounted fluoride toothpaste / mouthwash.

From my understanding, fluoride works best when put directly on teeth (e.g. toothpaste / mouthwash), and doesn't work so well if you drink it.

eptcyka• 1 year ago

I wouldn't put vaccines in the same pot as whatnots.

bregma• 1 year ago

But aside from the iodized salt, sanitary sewers, shoes, vaccines, and whatnots what have the Romans done for us?

duskwuff• 1 year ago

TL;DR: hookworm eradication in the American South substantially improved school attendance and educational outcomes in children, and may have had a nontrivial positive effect on the overall economy of the region.

(In case you don't see the connection, some children had such severe hookworm infestations that they were too anemic to focus in school, or even to attend at all. Teachers' accounts specifically remark on their students' newly "rosy cheeks" - because they're no longer anemic.)

throw745859• 1 year ago

But hookworm recently returned. There are also all sorts of parasitic worms that coexist with men. Pets require periodic vaccination, but most owners are deniers or just do not care!

Remember that, next time you step into dog shit!

FuriouslyAdrift• 1 year ago

Hookworms and the Myth of the "Lazy Southerner"

https://www.pbs.org/video/gross-science-myth-laziness/

zwieback2• 1 year ago

I grew up in Germany where iodized salt and flouridated water aren't the norm. Now I have bad teeth and can't wrap my head around the latest changes in the C++ language...

jeffbee2• 1 year ago

Switzerland is the exemplar of a place without environmental iodine, right?

greenavocado• 1 year ago

Any landlocked country without access to ocean water for irrigation and drinking. Heck, even the American midwest is notorious for having little iodine in its soil.

spacemanspiff01• 1 year ago

Can't comment on the bad teeth, but I don't think iodine is causing your c++ issues...

cgh• 1 year ago

Denmark iodizes its salt. Therefore, C++ is unnecessarily complex.

eddythompson80• 1 year ago

I guess there is a reason Germans blamed the Jews for all their bullshit.

virtualritz• 1 year ago

10 out of 10! :D

carlmr• 1 year ago

Iodized salt is quite the norm in Germany. You can buy the non -iodized version which is better for bread baking. But most everyone I know has iodized salt at home.

Also doesn't water fluoridation cost a few IQ points? In the end I could imagine the effects cancelling each other out.

WorkerBee28474• 1 year ago

Also doesn't water fluoridation cost a few IQ points?

Yes

https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/...

jandrewrogers2• 1 year ago

Also doesn't water fluoridation cost a few IQ points?

No, it does not. This is speculation based on a poor understanding of the actual science.

Most of our fluoride exposure comes from eating normal food, water fluoridation is a small fraction of that. There are no measurable cognitive effects in the many developed parts of the world with natural fluoride levels far higher than used in municipal fluoridation. Furthermore, there is no plausible mechanism of action for how this would cause a cognitive deficit. Fluoride toxicity is well-understood because it has an unusually simple biochemical mechanism. Therefore it isn't surprising that the handful of low-quality studies that show a weak relationship to IQ loss don't replicate.

As someone who actually worked on fluorine chemistry, it is disappointing to see how credulous even many people with a STEM background are on this topic. The absence of a plausible mechanism of action alone should raise serious questions.

Night_Thastus• 1 year ago

I think you have it backwards. If you can easily wrap your head around the latest C++ changes, then you should be concerned.

pentacent_hq2• 1 year ago

That’s not true. Iodized salt is the norm in Germany. I couldn't find data more recent than 2018 but according to this paper, "iodized and fluoridated salt has a market share of 80-90% among salt sold to private households": https://jlupub.ub.uni-giessen.de/items/fcd6e613-49a9-414b-a4...

blargpls• 1 year ago

I think you made a typo. Your source says it's 70-80%.

So liegt der Anteil von jodiertem und fluoridiertem Salz in Haushaltsgebinden seit Jahren zwischen 70 und 80 %

zwieback2• 1 year ago

Good to know, must have gone up since I moved away in '92

cubefox3• 1 year ago

Iodized salt has been the norm for a while in Germany...

pessimizer• 1 year ago

According to the current best guess, fluoridation lowers IQ scores:

https://jamanetwork.com/journals/jamapediatrics/fullarticle/...

Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride Exposure and Children’s IQ Scores: A Systematic Review and Meta-Analysis. JAMA Pediatr. Published online January 06, 2025. doi:10.1001/jamapediatrics.2024.5542

jrootabega2• 1 year ago

Iodine is a critical micronutrient in the human diet — that is, something our bodies can’t synthesize

For this I am thankful. If your body DOES start synthesizing iodine, you and those around you probably don't have much longer left to live.

frabert• 1 year ago

I long for the day when my liver can also act as a particle accelerator

xattt• 1 year ago

The kidneys? A pair of calutrons.

altairprime• 1 year ago

smiles in katalepsis

blueflow• 1 year ago

Explanation: Iodine is a molecular element, it consists out of only one type of atom. Atoms being synthesized implies some nuclear reaction or decay going on, both would cause radiation.

iugtmkbdfil834• 1 year ago

Thank you. For the life of me I could not figure out why that is true.

MawKKe• 1 year ago

I mean, it's possible that at some point evolution produced such nuclear reactored individual, but who got "naturally selected" rather quickly for obvious reasons

cubefox3• 1 year ago

Yeah, from Wikipedia:

An essential nutrient is a nutrient required for normal physiological function that cannot be synthesized in the body (...) The nutrients considered essential for humans comprise nine amino acids, two fatty acids, thirteen vitamins, fifteen minerals and choline.

While some of these can be synthesized by other animals, this is not the case of minerals like iodine. I believe only organic compounds can be synthesized by animals.

SAI_Peregrinus• 1 year ago

Our bodies can synthesize several inorganic compounds, and other organisms can synthesize even more. There are biological sources of $H_{2}O$, $NH_{4}^{+}$, $NO$, $HCO_{3}^{−}$, $HPO_{4}^{2−}$, and (traditionally considered inorganic despite having carbon) $CO_{2}$. Iodine is an element, not a compound, and can only be synthesized through nuclear processes, not chemical ones.

mr_toad• 1 year ago

Does respiration count as synthesis?

freehorse• 1 year ago

Minerals (as the term is used in nutrition, not in mining) are chemical elements, not "compounds". They are part of the constituents that can be synthesised into compounds. Usually our bodies obtain them in some form of organic or inorganic salts, which are compounds, so we obtain them as parts of compounds. To synthesise compounds that contain iodine, you need iodine in some form. As we are not talking about nuclear reactions through which elements are synthesised through other elements, there is no way humans, animals or plants synthesise any minerals like iodine, we all obtain them from some source. The original sentence is weird, because it talks as if iodine can be synthesised somehow chemically but just our bodies are unable to.

poulpy123• 1 year ago

or you become the main character of a superhero comics

MichaelNolan• 1 year ago

Further reading from Gwern - https://gwern.net/iodine

davidgay• 1 year ago

https://www.lrb.co.uk/the-paper/v45/n23/jonah-goodman/a-nati... is a pretty good article describing how a Swiss doctor showed experimentally that adding iodine was a cure for goitre and the associated mental handicaps (Switzerland is highly deficient in iodine in many areas, because glaciers in the last ice age removed most top soil).

kazinator5• 1 year ago

something our bodies can’t synthesize

Iodine is an element! As such, it cannot be produced by a chemical reaction and so isn't synthesized in any living organism.

It's produced in supernova explosions, by the rapid neutron capture process.

anal_reactor• 1 year ago

I'd argue that it's not completely unreasonable to claim that stars are living organisms in some sense of this expression

djtango• 1 year ago

After studying atmospheric Chemistry I found it hard to not feel like our planet was alive in some sense of the word but "alive" has a very precise meaning and Earth doesn't fit the definition. Presumably because it doesn't reproduce

mjcohen• 1 year ago

Then you might enjoy "Star Maker" by Olaf Stapeldon. It is available on Amazon.

amelius3• 1 year ago

So, what is wrong with the statement?

jrootabega2• 1 year ago

At best, it doesn't say anything useful. You can say the same thing about carbon, nitrogen, hydrogen, etc.

At worst, it implies that, like essential amino acids, it CAN be synthesized by some living organism.

kazinator5• 1 year ago

If "wrong" means "false", then nothing!

While the statement is not false, it has a kind of type error. Iodine is not in a category that can or cannot be synthesized in organisms (or any chemical reactions). We only talk about molecules in this category: e.g. Vitamin C can be synthesized in some organisms, but not others.

The following is also not a false statement: household waste isn't handled by the JVM garbage collector. However, at least we know it was written in jest. To nitpick that one would be to betray not getting the computer science dad joke.

hilux• 1 year ago

Iodine is also found in seafood and dairy and eggs, which may have been less common in the American diet a century ago, especially among the poor, but are widespread today. Americans no longer need iodized salt. (Not sure about vegans.)

6SixTy2• 1 year ago

Vegans should already be extremely watchful of their nutrition, as there's for example B12 in a lot of animal products, where a B12 deficiency means you are getting nerve damage.

cogman10• 1 year ago

It's definitely in seafood. Dairy and eggs depend on what the cows and chickens have been fed. In regions with low soil iodine content, you can expect the eggs and milk to also be low in iodine.

Vegetables and grains also have a significant amount of iodine in that sort of soil (it's where the cows and chickens get it).

hiroshi3110• 1 year ago

In Japan, iodized salt is banned as a food additive. because we can take it from see weeds like kombu.

ycombinatrix• 1 year ago

Why would that be a reason to ban iodized salt?

xiande04• 1 year ago

Even without iodized salt, Japan is one of the highest consumers of iodine worldwide. [1]

But I agree. Even though iodized salt is pointless in Japan, so is the law banning it (assuming OP is correct, and it is in fact banned).

[1] https://anaturalhealingcenter.com/documents/Thorne/articles/...

slongfield• 1 year ago

Too much iodine can lead to thyroid problems, and this has been a problem in some subgroups in Japan: https://academic.oup.com/jcem/article/107/6/e2634/6516999

tguvot2• 1 year ago

need to cook food for dog due to medical reasons, and one of ingredients is iodized salt. so i had a quick look at this topic. so, as far as i remember:

- different brands have different amount of iodine

- iodine dissipates from opened salt container, with speed of dissipation been dependant on temperature and humidity

- if you cook with iodized salt, most of it iodine disappears (depends on brand. some retain more )

puzzledobserver• 1 year ago

I had never thought about point 1, and never knew about points 2 and 3.

Growing up in India, iodized salt was the norm. Given that I'm vegetarian, now that I have moved the US, I have continued to use iodized salt for my own cooking. Whatever Morton / Kroger / other grocery store brand is most readily available. I usually keep it stored in an airtight plastic jar but use it for cooking like normal.

Should I be worried about iodine loss during cooking?

tguvot2• 1 year ago

depends on amount of salt that you use and your nutritional requirements...

for my dog I add salt after cooking. she won't know the difference

ufo3• 1 year ago

Regardless, on average it tends to work out. The amount of iodine in the salt is regulated by measuring uring samples in a large population.

joseph_b• 1 year ago

I wonder if I got my share of iodine growing up, or maybe too much, while playing with nitrogen triiodide?

speed_spread• 1 year ago

Considering a clear distinction between "slowly growing up" and "quickly expanding in all directions", that you managed to grow up at all proves that you didn't have too much.

taeric4• 1 year ago

This has me curious on how I would know if my family needs more iodine? We have largely been on kosher salt for a long long time. It is just more pleasant to use while cooking.

I could, I think, just switch a lot of what we do back to iodized salt? Feels pointless if not needed, though.

29athrowaway3• 1 year ago

You likely eat other kosher products that do not use "kosher salt".

Using "kosher salt" is not always a requirement for a product to be kosher. Technically all salt is kosher if it is produced under kosher supervision, even if it's not "kosher salt".

(And some salt labeled as "kosher salt" can also be not actually kosher!)

"Kosher salt" should be rather called "koshering salt", which is the salt you would use for koshering meat.

And like most people, you likely eat more salt than strictly needed because there's salt in everything. So consuming more salt should be of least concern.

taeric4• 1 year ago

Oh, I should have been clear there, I don't do kosher because it is "kosher." I just like the larger flakes and it is easier to cook with from familiarity. I'm assuming with time I could get used to iodized again, but not at all clear if I need to.

And we have actually been doing quite well with not eating out too often. Literally less than 5 times all month. Such that I am not at all worried that we are getting too much salt.

Though, that starts getting at the general question. How often should I get blood work for nutritional analysis? Because.... I don't know that I've ever done that.

bilsbie• 1 year ago

Isn’t there a lot of iodine in dairy?

dchristian• 1 year ago

That depends on if it's in the grass that the cows eat. They first researched iodine in cows because there isn't much iodine in the grass around the great lakes. This area was known as the "goiter belt".

Adding iodine to the cow's food made them healthier and that's how they estimated the dose for humans (mcg / kg).

cbracketdash2• 1 year ago

A significant source of declining iodine levels in humans can also be traced to increased bromide found in food and medications. Most notably potassium iodate was used as a bread conditioner until the 1950s when it was substituted for potassium bromate. [0]

Excess bromide levels displace the iodide stored in the thyroid and is a contributing factor to the described increase of groiter. Bromide also has the added drawback of increased cancer risk and has now been banned in California [1] [2].

[0] https://pmc.ncbi.nlm.nih.gov/articles/PMC3916868/

[1] https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml...

[2] https://web.archive.org/web/20131203041405/http://www.oehha....

red-iron-pine• 1 year ago

bromide in flour is a uniquely US thing too, and IMO you can taste the difference when you eat bread in other places.

cbracketdash2• 1 year ago

Yes, and there is anecdotal evidence of improved health and loss of gluten allergies when traveling to Europe for vacation! (Probably confounding factors but still worth considering)

CactusBlue• 1 year ago

In Korea, people often have seaweed soup. Seaweed is very high in iodine, so most people in South Korea doesn't use iodized salt.

yongjik• 1 year ago

Seaweed, man. Buy a bag of dried kombu, plop a piece when you're making soup or broth: it goes well with most flavors, and will give you all the iodine you need.

Disclaimer: not meant to be medical advice, obviously.

Adding iodine to salt played a role in cognitive improvements: research (2013)

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