How Adding Iodine To Salt Resulted In A Decade's Worth Of IQ Gains For The United States

[dixiegrrrrl]

Iodine deficiency remains the world's leading cause of preventable mental retardation.
According to a new study, its introduction in America in 1924 had an effect so profound that it raised the country's IQ.

A new NBER working paper from James Feyrer, Dimitra Politi, and David N. Weil finds that the population in iodine-deficient areas saw IQs rise by a full standard deviation, which is 15 points, after iodized salt was introduced.

Since one quarter of the population lived in those areas, that corresponds to a 3.5 point increase nationwide. We've seen IQs go up by about 3 points every decade, something called the Flynn effect, so iodization of salt may be responsible for a full decade's worth of increasing IQ in the U.S.

http://www.businessinsider.com/iodization-effect-on-iq-2013-7

Amazing...I had no clue about the "incidental" benefit of iodized salt.

[Cirque du So-What]

1. That's news to me

The article didn't go into it beyond merely mentioning the connection between iodine and goiter prevention, but there must be some connection between thyroid function and the entire endocrine system that influences mental functioning. I know that hypothyroidism can cause symptoms that mimic mental illness.

[roseBudd]

5. I am looking forward to omega-3 modified soybeans...

I just really Fucking Love Science

http://www.soyconnection.com/newsletters/soy-connection/health-nutrition/articles/A-New-Sustainable-Source-of-Omega-3-Fatty-Acids

[Igel]

9. It's developmental.

In utero and in infancy, I deficiency apparently results in cognitive difficulties.

I like how they quantified things using goiter incidence. NW and N-Central US had high rates. So Oregon, Washington, Idaho, Montana, Michigan, and states near there had higher incidence of goiters. So plausibly less I in the dirt and water. The chart is provided.

Then they looked at military induction tests and who scored high and where they were from. Young men from those areas had a lower incidence of high scores and averaged lower than the national norm until nearly 20 years after the introduction of I in salt.

Then they double-checked. If you're low in I for years and suddenly are exposed to enough, your overdeveloped thyroid will pump out excess T3 and T4, resulting in hyperthyroidism. And lo--that's exactly what they found in the years after I was introduced, and the prevalence of hyperthyroidism matched the general predictions by area.

Nicely done.

[kimbutgar]

2. I read that ironized salt is the reason a lot of people have high blood pressure

I am 57 both my parents and sister have high blood pressure. I switched to sea salt about 5 years ago. My blood pressure is normal and my husband who takes blood pressure medicine hasn't had to increase his dosage. His blood pressure has stabilized. Getting off blood pressure meds are extremely difficult. You only use a little sea salt where you end up using more ironized salt.

[dhol82]

4. ummmmm

Do believe that sea salt does have iodine in it. The reason it was added to table salt was that most of the population was not near the ocean to get the benefit of iodine from seawater. And, oops, just learned that the level of iodine in sea salt is not as high as the mined salt.

http://en.wikipedia.org/wiki/Iodised_salt

http://www.healthytheory.com/sea-salt-versus-table-salt-is-one-better-than-the-other

Some believe that sea salt is a healthier alternative. It is true that sea salt contains slightly less sodium than standard table salt. Sea salt is about 30% sodium by weight; table salt is 40%. Sea salt, made by evaporating seawater, also typically contains additional important minerals, such as magnesium, calcium, and potassium, although in very small amounts. Table salt, on the other hand, is mined from rock salt through an industrial operation which removes many of these minerals.

There are physicians who believe that whole, unrefined sea salt is better for you, and that blood pressure and overall energy improvements have been seen after switching from regular table salt. But to date, there have been no clinical studies to prove this possible benefit.

Some gourmets feel that sea salt is superior to table salt in taste and texture. According to the Food Network, the finer table salt is preferred in products that require quick dissolving of the seasoning, such as in baking. Sea salt and kosher salt, because it is coarser and larger, is more often used as an after-cooking seasoning just before serving.

One possible downside of sea salt is that it is lower in the mineral iodine. Iodine is a trace element required for the synthesis of thyroid hormones. Sea salt contains 64 micrograms of iodine versus 46-76 milligrams in standard iodized table salt. The Recommended Dietary Allowance for most adults as set by the Food and Nutrition Board is 150 micrograms a day. Dietary sources of iodine include fish, milk, and potatoes.

[mainer]

10. All salt was originally sea salt.

The salt mined from deep underground comes from ancient dried sea beds.

And really, except for the taste of impurities that may change its color or add other flavors, salt is still sodium chloride. So I think "sea salt" is just a marketing ploy to make you buy more expensive sodium chloride.

[Aristus]

11. Thanks for this. You saved me a lot of typing.

I have patients with high blood pressure who tell me that they have switched to sea salt. I tell them that the switch will make no appreciable difference in their blood pressure levels. To a certain degree, especially concerning sodium's relationship to hypertension, salt is salt.

I advise them to reduce their total overall consumption of sodium, and to increase cardio exercise.

[roseBudd]

6. Have you looked into the DASH diet?

http://www.mayoclinic.com/health/dash-diet/HI00047

[eppur_se_muova]

3. Meddlesome nanny state ! nt

[aquart]

7. And yet....Congress.

[bluedeathray]

8. ^^^FOR SURE!^^^