On page 88 of Germs, Guns and Steel, Jared Diamond mentions in passing the role that large, domesticated animals serve in nourishing early agricultural communities—they provide meat, aid in crop production, can be used as farm hands, and can be milked. These mammals, Diamond says, “yield several times more calories over their lifetime than if they were just slaughtered and consumed as meat.” For a family with a plot of land and many mouths to feed, this self-sustaining model is fantastic. Compared to other species in the animal kingdom, though, humans are quite odd. We’re the only mammals that consume milk after infancy, surprising because lactase, the enzyme needed to digest lactose, is highest just after birth and diminishes with age (hence lactose intolerance), suggesting that milk is perhaps only necessary and beneficial in the first few months of life.
When I think of milk and milk products, one thing I always bounce back to is who in their right mind decided to milk an ungulate’s udders?? It’s a little bit weird! I’m not that naïve, though—I realize that milking is only mimicking what babies of many species do to obtain nutrients and calories from their mothers. But why, after exhausting our human mother’s resources, do we find it necessary to switch to milk from other species and use it for milk, cheese, yogurt, ice cream and other dairy products? According to the ever-trusty Wikipedia, milking animals coincided with the development of agriculture, appearing independently in 9000-7000 BC in Southwest Asia and 3500-3000 BC in the Americas. There are many theories about how and why humans came to milk animals, a marked departure from the diet of a hunter-gatherer, who would probably consume virtually no dairy. While it remains unknown exactly when and how dairying came to be, it’s certainly a livelihood for many and a considerable part of the SAD (Standard American Diet) and diets in other parts of the world.
As an aside, from the general information that I know about lactose and lactase and human’s uniqueness in dairy consumption, I have to question doctors’ recommendations to drink more milk. The idea that the calcium in milk is necessary for strong bones and proper growth (which can be found in other foods) is one of the government’s party lines (see My Plate and past food pyramids). If dairy is a relatively new addition to the diet, though, is it really necessary?