Iodine: experimental design to test benefits
gwern
31 May 2012
So I was looking into iodine & IQ, and I found one or two studies that tested it in adults: http://www.gwern.net/Nootropics#iodine
I was interested in testing it in myself, but the two studies were both null results. When I did the power analysis (http://www.gwern.net...#power-analysis) on how long an experiment I'd need to detect a smaller effect in myself, I came up with 102 pairs of before-afters. Not too bad? But the big study had supplemented over *32* weeks, so 102 pairs would be ~5 years!
That's just not doable. So doing some more figuring (http://www.gwern.net/Nootropics#voi), the rational thing to do is take some moderate small supplement and not bother experimenting. But I really hate that idea of not testing it!
So I have some questions for Longecity.
1. Do you think 32 weeks is excessive for each block? Could something more reasonable like 5 weeks be sufficient for iodine supplementation to take any effect during active blocks and then wash out during placebo blocks?
2. What sort of tests would be good to use? IQ tests would exhibit too many practice effects and I'd have a hard time getting 204 tests anyway.
3. Did I miss any studies on adults?
4. What possible other changes could I track? I noticed the eye color thread, which is weird but possible and easy to check, and so may be worth doing.
I was interested in testing it in myself, but the two studies were both null results. When I did the power analysis (http://www.gwern.net...#power-analysis) on how long an experiment I'd need to detect a smaller effect in myself, I came up with 102 pairs of before-afters. Not too bad? But the big study had supplemented over *32* weeks, so 102 pairs would be ~5 years!
That's just not doable. So doing some more figuring (http://www.gwern.net/Nootropics#voi), the rational thing to do is take some moderate small supplement and not bother experimenting. But I really hate that idea of not testing it!
So I have some questions for Longecity.
1. Do you think 32 weeks is excessive for each block? Could something more reasonable like 5 weeks be sufficient for iodine supplementation to take any effect during active blocks and then wash out during placebo blocks?
2. What sort of tests would be good to use? IQ tests would exhibit too many practice effects and I'd have a hard time getting 204 tests anyway.
3. Did I miss any studies on adults?
4. What possible other changes could I track? I noticed the eye color thread, which is weird but possible and easy to check, and so may be worth doing.
stephen_b
31 May 2012
Your design of experiment gets worse: you might have to take selenium into account. 
Ah well, biology is complicated.
Ah well, biology is complicated.
gwern
31 May 2012
Herman Gill suggested the same thing on Reddit: http://www.reddit.co...otropic/c4twqj7
baccheion
03 Jan 2018
"August 2013 blood test of TSH which put me at 3.71 uIU/ml, comfortably within the reference range of 0.27-4.20.)"Finished my meta-analysis: http://www.gwern.net...s#meta-analysis
A level between 0.8 and 2.0 is preferred/optimal. Above 3.0 is slightly hypothyroid. You can/should look into The Iodine Protocol.
Edited by baccheion, 03 January 2018 - 04:52 PM.
