Kevin Klatt, PhD, RD

A new Nature article came out the other day that addresses a major question in the story of lactase persistence, one of the strongest gene-culture-selection interactions: did hunter-gatherer populations adopt dairy'ing or did dairy'ing cultures migrate and replace these HG populations? I really love this type of research, not only for its profound insight into the past but also the interdisciplinary team that participated in elucidating these facts. I often find myself thinking I need to be a biochemist/molecular biologist/genomicist/bioinformatician to answer all the  questions I have about nutrigenomics - but in this effort alone, there were anthropologists, paleogeneticists, bioarchaeologists, mathematicians, and archaezoologists. To solve the issue of dairying's origins, researchers looked at the bone remains - since calves need to be killed earlier than a cow raised for slaughter, looking at a bone's age can give insight into whether individuals in the time per...

It'd be impossible to discuss nutrition and genetics without discussion human milk consumption and lactose (in)tolerance. This example is iconic in that it has huge evolutionary and nutrition implications. From an evolutionary perspective, lactase persistence's relatively widespread distribution is largely due to the success of the agricultural revolution. Milk provides an excellent source of calories, nutrients, animal based amino acids and, often not considered, hydration to any species that can consume it. For most humans, and mammals in general, milk is food for infants. Following weaning, there is low digestive capacity of lactose, and for humans, milk consumed in a non-fermented form in excess of 500mL can be quite uncomfortable. There is potentially good evolutionary reason for this loss of lactase persistence: lactase is able to digest some glycosides found in plants, such as berries and nightshade plants, that would allow for the release of cyanides and other toxic s...