My open source brain data
medium.com
medium.com
I tracked diet, and my estimates of mental functions for a while and surprisingly found that strawberries increased my mood considerably. Of course I could just be bad at statistics :-(
I noticed they're high in vitamin C so I was thinking maybe it was related to that.
If I recall I did a correlation analysis, between foods and mood and strawberries related jumped out strongly.
If the serotonin manages to make it into your bloodstream (e.g. if your gut bacteria don't want it, and your stomach pH isn't low enough to destroy it, and your gut permeability is high) then you'll certainly get a mood boost.
As noted, as long as you don't start drawing any conclusions before you've played consistently to eliminate practice effects (getting better at the games) as best you can, it's fairly interesting and valuable stuff.