[rwallace]

Okay, but let's stop and think about it for ten seconds: Of course drinking a slightly different brand of milk doesn't make you live 4.5 years longer; the headline claim is obvious nonsense. (And as I understand it, it's now thought that to the extent there is any difference, it's in favor of the high-fat milk.)

So then the conclusion seems to be that confounding factors have an extremely strong effect on the conclusion, even when the investigators have tried hard to screen them out.

Why? What went wrong with the attempts to screen out the confounding factors?

[fermenflo]

To be fair, it's a pretty large claim to just assume that something "went wrong with the attempts to screen out the confounding factors" and that the conclusion must be false.

It's a shocking conclusion, I'll give you that. And to be honest, I'm not convinced either. You might very well be right. But it's a strong claim to make agains a peer-reviewed journal publication.

[gus_massa]

> But it's a strong claim to make against a peer-reviewed journal publication.

Remember that peer-review only means that two or three persons had read the manuscript and found no obvious error and think it's inteligible and interesting. It doesn't mean that the reviewers had reproducer and checked all the details.

It is more trustworthy that a webpage in all-caps with white text over a black background, but it depends a lot of the journal. There are serious journals, and there are crappy journal that publish any rubbish if you pay them.

This is not may area, so I'm not sure. I looked at the other articles published in the journal and they look fine, but this is not my area. (Crackpot articles tend to aggregate, so looking at the other articles is sometimes useful.)

It's is very strange that an article about 5834 persons has only one author. Again, this is not may area, but I'd expect 5 or 6 authors. (The other articles in the journal have multiple authors.) It's not a smoking gun, but it's very strange.

In the article, the more interesting part is table 4 https://new.hindawi.com/journals/omcl/2019/1574021/tab4/ It looks fine. I didn't redo all the calculations, but it looks fine. (It may be a professional defect I have, but for me most articles are "Bla bla, bla bla, important table, bla bla.".) The table looks nice.

Also, they are measuring telomere length, not a self reported coefficient. I never trust self reported data. (Some of the covariant they use are difficult to measure like "percentage of total energy derived from saturated fat". How did they measure that? Anyway, I don't expect that to be a problem.)

It's important to wait until the study has been reproduced. (Exact reproductions are difficult to finance and publish, but you can make a twist. For example comparing the four combinations of normal vs cocoa milk and 1% vs 2% milk.)

@GP: Note that the (research) article does not claim that you live 4.5 years longer. They claim that the telomeres are reduced approximately 145 bases, that is somehow equivalent to 4.5 years of aging. Probably having 145 less bases in the telomeres increase some illness, but I doubt it affect too much the accident death rate.