The research was about the effect of your diet on dementia. When looking from an evolutionary perspective, I don't think that the chance of developing dementia

The research was about the effect of your diet on dementia. When looking from an evolutionary perspective, I don't think that the chance of developing dementia was very important. Most people never reached that age and when they did, they probably couldn't reproduce anymore anyway. So I don't think your argument about beans can be used to invalidate the findings of the research.