chocolate and memory, this time reviewing the reference

chocolate (actually dietary epicatechin) does increase the dentate gyrus function on functional MRI and improve cognitive testing in only 3 months (see chocolate and cognition. nature neuro 2014 in dropbox, or  doi:10.1038/nn.3850). a couple of other observations from the paper.

--data in mice show a synergy between flavanols and aerobic exercise in enhancing dendritic spine density in the dentate gyrus

--this increase in both function (mice have improved cognitive performance with flavanols) and structure occur in association with an increase in capillary density in the dentate.

--the researchers developed a cognitive test, which mostly was looking at a large series of complex images, then 1 second after each image they asked which of 2 similar objects was present in the complex image, timing the subjects’ responses. Each time the test was performed, different images were used.

--they tested this cognitive eval  in undergraduates and in healthy subjects aged 21-69, finding that there was a worsening with aging. And this was worsening was associated with the images on functional MRI.

--then, as per the NY Times, they had their dietary flavonoid  intervention in people aged 50-69. But, not in the Times, they also did so in both sedentary state and with exercise (1h/day of aerobic exercise, 4 days/week). So, there were 37 individuals distributed into the 4 groups (high vs low flavanol diet, and with vs without exercise), comparing before and after.

-- the high flavanol diet led to significant cognitive improvement independent of exercise. No effect of exercise, but rather unexpectedly, the VO₂ max was no different between the groups with and without the exercise (???).the changes in cognitive function was “equivalent to improvements in cognition by approximately three decades of life”

--the changes in the cognitive function correlated with changes in cerebral blood volume on imaging

--the improvements in blood flow has been shown in several prior studies of flavanols (and also with exercise, in several other studies).

--prior studies (including by this group) have shown that aerobic exercise typically improves hippocampal function

So, there it is. A small study with multiple components that are (it seems to me) pretty impressive. Data from animals and humans provide many of the pieces: flavanoids increase blood flow, including cerebral blood flow in the hippocampus; there is an association in mice with flavonoids increasing neural density in the dentate gyrus, which was tied into increasing blood flow; and functionally there are impressive changes in cognition in humans and mice. Bigger studies would be useful.  As well as chocolate bars with high and known levels of flavonoids.  I’m game to try them…..