by Brio Personal Training
12. February 2010 12:53
Food or Not Food?
Milk is one of the primary no-nos on a paleo diet, because through 99% of human evolution we've been chasing down and killing large game to eat rather than chasing them down to milk them. The paleo philosophy is to eat the foods generally available to your caveman ancestors and to steer clear of those that weren't Humans are equipped to handle milk (human breast milk) through infancy and the toddler years because we produce an enzyme called lactase that helps break down the milk sugar called lactose. In most people, the production of this enzyme stops sometime in early childhood and we lose our ability to digest milk products. It wasn't too much of a stretch in terms of human evolutionary development that some people would possesses a genetic variant that had them continue to produce the enzyme lactase through the entire lives (it's called lactase persistence). As humans began to domesticate animals, a nutritious and plentiful food source was available to those who could digest it and so they survived and thrived to pass along this genetic variant.
It makes sense then that lactase persistence occurs most frequently in people descended from areas of the world where agriculture was established the earliest (around 12,000-10,000 years ago in the fertile crescent). Lactose intolerance is most common in people from areas of the world exposed very recently (perhaps only a few generations ago) to the food staples of agriculture.
We've certainly seen this difference in our own athletes who give up dairy for a month as an experiment. Some are quickly relieved from the previous nagging afflictions of asthma, acne, chronic phlegm, nasal allergies, indigestion, gas, bloating, etc. And others experience no difference at all. Some simply cannot handle dairy and other do just fine with it. The only way to know which group you fall in to is to do this experiment with yourself.
Check out this study for some interesting genetic research on this topic...
Red is high frequency of lactase persistance (tolerance of dairy products) and blue is the lowest frequency.