About pellegra - you're right. I added more examples. Better example: When health-food advocates talk about how whole grain bread is more nutritious than bread

About pellegra - you're right. I added more examples. Better example: When health-food advocates talk about how whole grain bread is more nutritious than bread made with just white flour* , they sometimes note that people favored white flour because of some elaborate cultural subtext about whiteness and purity. That's BS - it's because without refrigeration, the oils in the bran go rancid . Readily available whole grain bread is actually a modern luxury, thanks to transportation infrastructure and pervasive refrigeration. White flour has a much longer shelf life, so it was common historically - it's not junk people started getting fed recently due to some evil processed food conspiracy. * Spoiler alert - it is, and it often tastes better.