[erroneousfunk]

The article didn't imply at all that the factors were directly related. The CDC is tasked with finding health information and trends in the population. If they're missing a large, segment of the population that has very different health trends than the rest of the population, that's a problem and they want to address it, no matter what the reasoning behind the correlation is.

They did talk about controlling for age and income in the article. While the effect was reduced, it was still there. So I'm not entirely sure what your point is, based on the article.