Monday, February 27, 2012

The Evolution of Dairying

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 na├»ve, 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?

3 comments:

  1. I've also had some issues with why exactly the importance of drinking milk is so highly emphasized in the US and where this came from. I understand that milk is relatively cheap and highly useful for making certain products like yogurt that are actually good for our health, but drinking milk to the extent that people do in the US is a different matter. Having grown up in southern Italy, I never drank glasses of milk with my meals as a child, and the milk that we purchased to use in cooking was typically not pasteurized and came in very small bottles since it had to be used within 3 days at the most. When we eventually moved to the I actually found it really disgusting that they served cartons of milk to drink with lunch and that when going to friends' houses for dinner I was offered large glasses of milk to drink with my meal. To me it seems unnatural to drink milk in such a high quantity, especially given the fact that most milk in the US is riddled with hormones and antibiotics, and we can get calcium from other sources such as kale and spinach which is actually easier to absorb than the calcium found in milk.

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  2. I absolutely agree with both of you. Milk is a puzzling United States phenomenon that will probably always confuse me. Proponents of industrialized agriculture meet several times a year to hold forums about the role dairy products play in the SAD and economy and constantly utilize the phrase "we need more." "We need more" because there are very high rates of osteoporosis in the U.S, but this problem hasn't been kicked with milk consumption and osteoporosis is actually on the rise. I find it so silly that most states in the U.S ban raw milk and raw milk byproducts which are best in aiding digestion and contain vast quantities of acidophilus and other beneficial probiotics our bodies require. We're so scared of the natural ways in which we'd get sick (harmful bacteria in non-pasteurized food products) that we neglect the more obvious, unnatural ways we continuously get sick--over-consumption of dairy (which is proven to lead to inflammation and congestion.) While I think there are multiple caveats with Diamond's thesis--mainly, that geographical determinism neglects inequalities deeply entrenched although not predestined in various societie, I do believe that caloric intake with dairy products has allowed certain societies to grow, albeit not healthfully.

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  3. I would like to disagree, although I guess it is necessary to say that I grew up drinking milk, and still do. How is milking a cow deemed un-natural in today's time if we have been doing it since ~9000 BC? Milk is essentially water, saturated fat, lactose, protein, and vitamins+minerals (most notably vit.C and calcium). It is a decent source of protein, with approximately 1g protein / oz. This means that one cup of milk has 8g protein. As we have learned in lecture, (and probably otherwise) protein is a longer lasting source of energy than sugar, and therefore a glass of milk is probably a better and healthier choice for high-energy-consumptive children than almost anything but water.

    Additionally, I do agree that milk has been proven to have an inflammatory effect, but drinking milk very rarely causes adverse health effects, barring lactose intolerance/allergy, and the effects human-added growth hormones such as IGF-1[insulin-like growth factor] and rbGH [bovine growth hormone]. The main gripe about milk is the presence of IGF-1, a growth hormone meant for young animals. However, while it is indeed naturally present in cow's milk, the adverse health effects manifest themselves when the subjects drink milk from cows which have been injected with the hormone in order to produce more milk. Buying "rbGH free" milk also means that there is non-significant amounts of IGF-1 present, and is safe.
    Milk is surely not the elixer of life, but "as a part of a balanced diet..." I think it has beneficial effects, especially when expanded with the presence of milk-based products such as cheese, yoghurt, etc.

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