The 1960's study was done poorly, they used dry seaweed when they should have used fresh seaweed that the people actually ate. That is the study that is referenced by quacks when advocating 12-18 even up to 50mg of iodine a day. A study in 2008 found that the average Japanese intake of iodine was 1.2mg from seaweed (upper tolerable limit for iodine is established around 1.1mg, sounds about right) Pointing to Japanese intake of iodine and arbitrarily saying that's probably why they love longer is no more conclusive than saying they probably live longer because they eat soy or sweet potatoes.
We eat dried seaweed all the time because it just tastes good (we live in Monterey). Get some calrose rice in the cooker, get your little strips of dried seaweed, make little rice rolls. This is my daughter's favorite snack, and often she just wants the seaweed to crunch on
Agreed, reminds me of the 'X culture drinks X cups of green/black tea a day'.
And it turns out they do - but they keep using the same tea bag.