Here is why you have to read original peer-reviewed research—not just the popular media’s summary of it, or interim findings presented at conferences.

Red Wine Goes To Your Head – But Helps You Think – Medical News Today – April 3, 2009

“Red wine extract polyphenol resveratrol could improve mental performance on demanding tasks.
[…]
The results showed a change in blood flow to the brain and significant improvements in cognitive performance in the participants who had been given polyphenol resveratrol.”

This is a surprising claim: nowhere have I seen resveratrol claimed or marketed as a cognitive enhancer. So I looked up the paper by Wightman et. al.

Effects of resveratrol on cerebral blood flow variables and cognitive performance in humans: a double-blind, placebo-controlled, crossover investigation.
David O Kennedy, Emma L Wightman, Jonathon L Reay, Georg Lietz, Edward J Okello, Anthea Wilde and Crystal F Haskell

“Resveratrol administration resulted in dose-dependent increases in cerebral blood flow during task performance, as indexed by total concentrations of hemoglobin. … Cognitive function was not affected.”

Well!

Note that this paper is dated June 2010, whereas the original article is dated April 2009. Apparently the research, when finally completed, didn’t end up supporting Wightman’s claim—or the popular media’s marketing of it.

I am glad that I, as a US resident, can take control of my own health and dietary intake to a great degree…but the freedom to ingest what I want comes with the freedom to waste my money. We cannot separate these two freedoms. So: caveat emptor…especially when researching dietary supplements.