The FADS1 and FADS2 gene variants associated with fatty acid metabolism, for example, are found at high frequencies in Arctic Indigenous populations.

These variants appear to enhance the ability to convert the specific types of fatty acids found in marine mammal diets into the essential fatty acids required by the human body.

The traditional Iñupiat diet, high in marine mammal fat, was nutritionally adequate not just because of what the food contained but because the bodies that ate it had been selected, over many generations, to process it efficiently.

Cold exposure responses showed similar patterns.