And here's an example of another extrapolation - the extrapolation of presumed causality.
The study, Habitual intake of anthocyanins and flavanones and risk of cardiovascular disease in men, is amazing.
Not in that it's a great or conclusive study, but rather that despite the very clear first sentence,
"Although increased fruit intake reduces cardiovascular disease (CVD) risk, which fruits are most beneficial and what key constituents are responsible are unclear."a sentence that spells out the fact that while we know fruit consumption is healthful, we genuinely don't know why, the article goes on to conclude, despite not in fact testing for it, that certain fruits' anthocyanins and flavonone content reduce heart disease risk in men.
How'd they come to that conclusion?
Well they estimated how much anthocyanins and flavonones were consumed as a function of how much anthocyanin and flavonone containing fruit was reported in food frequency questionnaires and then looked at cardiovascular disease risk as a function of same.
Of course fruit contains more than simply anthocynanins and flavonones, so to suggest those were the causal agents of the study's findings is purely a guess.
So putting aside why the American Journal of Clinical Nutrition published an article with a hugely misleading title and conclusion (and how it passed through peer review as is), why did the authors of this US Blueberry Highbush Council funded study (blueberries contain anthocyanins) focus on presumptive causal factors rather than the berries themselves?
Hard to say. Though it's certainly not impossible that the study's lead author's 2013 patent, meant to provide phytonutrients (including anthocyanins and flavonones) to nursing mothers might have had some influence (and is probably something that should have been included in the study's confict of interest statement).
Regardless, one things's certain. For folks selling anthocyanin and flavonone supplements, studies like this one are a gold mine.