I agree most Asian digest rice better, northern Europeans digest diary better, Italians digest pasta better, Mexicans digest legumes better, eskimo's fish blubber, etc. It’s because they’ve adapted to their diet. How long the human genome adapts to dietary change is a question that scientists argue about. In fact we can’t be certain about what Paleolithic man/women ate, but we can be certain what they did not eat. Refined flour, salt, sugar, hydrogenated oils and milk.