A Requiem For Nutrition

 Two years ago from Cremieux Recueil Food Probably isn't Making People Smarter or Dumber 

It is thorough. You can almost hear him thinking "Someone is going to bring up this objection right away.  Let me nip that in the bud." I understand that, and my overlong essays of ten and fifteen years ago illustrate it. He casts far afield to head critics off at the pass (metaphor alert: where he can nip them in the bud) with a long discussion on the Flynn Effect, the observation that IQ's have been rising across multiple populations for over a century*. The first guess that people have on this is nutrition, because that has been shown to be true in terms of height, and nutrition has varied within cultures and among cultures because of war and famine, creating rather dramatic natural experiments. It was not a crackpot theory. However, when looked at more closely it hasn't held up.

 We have noted that 20-point Dutch gain on a Raven’s-type test registered by military samples tested in 1952, 1962, 1972, and 1982. Did the Dutch 18-year-olds of 1982 really have a better diet than the 18-year-olds of 1972? The former outscored the latter by fully 8 IQ points. It is interesting that the Dutch 18-year-olds of 1962 did have a known nutritional handicap. They were either in the womb or born during the great Dutch famine of 1944—when German troops monopolized food and brought sections of the population to near starvation. Yet, they do not show up even as a blip in the pattern of Dutch IQ gains. It is as if the famine had never occurred.

 

 Iodine improves IQ in fetuses; adults as well? A meta-analysis of relevant studies says no.

Micronutrient supplements in Nepal and Indonesia; exposure to lead; even Ramadan 

 Among the White British students, the month of pregnancy Ramadan took place in wasn’t related to test scores, and among Caribbeans, the same thing was true. But, for Muslims, scores were lower if their mother was pregnant during Ramadan, and maybe lowest at two to three months in. (But even that is only one point difference.) 

*And has now stopped, puzzlingly.