rationalskepticism.org

That's a different topic and well established but again shows how different people are. Many people not of European stock cannot digest cow's milk ( yogurt is okay ) and for some glutens is downright death defying ( my sister-in-law )
Others are seafood allergies. Inflammation is a huge topic with implications for heart disease and auto-immune conditions.

Hell afaik we have no idea why we have different blood types....I am willing to be shown we do.