Milk and other dairy products formed a large percentage of the Central Asian nomad's diet. How were these mostly lactose intolerant legendary mounted horse archers able to ride around doing battle while experiencing abdominal bloating and flatulence?

by ddxue

This study found 87.9% of ethnic Mongols from Inner Mongolia and 76.4% of Kazakhs from northwestern Xinjiang were lactose malabsorbers. Mare's milk has 40% more lactose than cow's milk and goat's milk has 10% less lactose than cow's milk. Fermentation greatly reduces the amount of lactose in milk but would they able to drink fermented milk all the time such as before raids and battles? How were they able to deal with this?

Muleo

Couple different things..

  1. Lactose intolerance isn't all that important. 90%+ of Koreans are lactose intolerant yet fluid milk consumption is slightly higher per capita than in the US. (Random example I know but I found this out yesterday). It doesn't seem to bother them. I know, I know, dairy is a bigger part of the Mongol diet and horse milk has more lactose, but my point is lactose intolerance is a little overstated. And indeed in his description of their diet, Carpini says "they drink mare's milk in great amounts" (though to be fair in later mentions he doesn't seem to distinguish between raw milk and alcoholid kumis).
  2. Eating lots of yogurt or other fermented products means you have lots of lactose digesting bacteria in your gut which digests the lactose (in milk) for you instead of lactase. So the benefits of fermentation go for longer than the short term reduction of lactose you mentioned, and the Mongols certainly ate a lot of yogurt/kumis.
  3. The Mongols didn't always eat dairy. Generally they did in spring/summer when grass was plentiful so animals produced a lot of milk. In winter they ate more meat and less milk. So they weren't reliant on milk constantly anyway.
  4. The Mongols didn't really drink fresh milk when on campaign. A mare would only produce milk when about to or having just given birth, not the most practical of war mounts. Instead they carried with them dried meats and dried milk/yogurt that could be mixed with water to produce a drink. And when desperate they would drink blood directly from their horses.