Seriously though, this is a core part of dietary concerns, it's almost a certainty that a Russian is going to have a slightly different reaction to foods than a European, due to centuries of eating different foods. I think it's only recently we've really started to discover that evolution isn't just survival of the fittest, but a considerably more complex mechanism that has immediate impacts after very few generations to very slight stimuli. Not to mention stuff like gut flora, environment during pregnancy, etc.