Possibly better food supply? They're also lighter skinned on average than the US. Your skin color makes a difference in absorption. Native European's skin evol

Possibly better food supply? They're also lighter skinned on average than the US. Your skin color makes a difference in absorption. Native European's skin evolved lighter for a reason, and that was to absorb more of the sun's benefits in a cloudier climate. The opposite is true for dark-skinned individuals; they do better in sunnier hot climates because their skin protects them from over-exposure.