My immediate reaction to this is that it is total nonsense … but.
There is a famous neurofeedback institute - Biocybernaut spreading the old wives tale that garlic & onions prevent alpha waves
I had to investigate as this guy charges $15K for a few days of EEG. Basically he seems to have a thing for some eastern traditions that shun these foods as being too frisky. Both onion & garlic can increase testosterone.
It seems lame that they are putting it out that consuming garlic suppresses alpha when there is zero scientific evidence of this. The guy even claims garlic is a brain toxin while research strongly indicates the exact opposite.
Its quite annoying actually.