Uhh, I think that's one very implausible idea. The links you put in talk about several reasonable hypotheses. None of them can explain the whole effect by themselves, but changes in nutrition and education would certainly contribute to IQ changes.

Flynn talks about IQ tests being a measure of abstract problem solving and symbolic thinking. Well, over the last 100 years, people have learned to deal with increasingly complicated machines in their daily lives, and we've better and better at interacting with them. Ever see comedians in the 80's joke about not being able to program their VCRs? When I see that now, I just think they're idiots, because that's a trivial task for most people who grew up with the technology. Similarly, my kids will probably think I'm stupid for needing to read the manual to set up a firewall on my computer.