Does Milk Really Do a Body Good?

Drink your milk! Some of us heard that command many times growing up, and most of us never questioned it. At some point, we all learned -- whether from our parents, our health science teachers, or ads on TV and in magazines -- that milk from cows provides not only calcium but also vitamin D and many other nutrients with numerous health benefits. Milk does a body good, doesn't it?

A growing number of consumer advocates and scientists don't think this is necessarily true. They question the long-held wisdom of regular milk consumption, and some of these people even believe milk poses substantial health risks to humans.

What's at the bottom of this backlash? Is there any truth to what the critics are saying, or is it just a storm in a cereal bowl?

The Changing Face of Milk

Some of the controversy surrounding milk lies in the way commercially available cow's milk has changed over the years. In general, milk consists of water, fat, protein, lactose, minerals, vitamins, and enzymes. But the exact composition of milk depends on what cows eat, their cycle of lactation, the number of lactations, and how the milk is processed. Today's commercial milk-production techniques can significantly modify the end product, changing it from its natural form to something quite different.

For example, most commercially produced milk undergoes pasteurization to destroy bacteria and pathogens that may be harmful to health. However, some people claim that raw, unpasteurized milk tastes better and is more nutritious than the pasteurized variety.

Get a clearer picture of the controversy with this Q & A.

Out to Pasture

Yes. Although pasteurization kills potentially dangerous bacteria, such as listeria, E. coli, and salmonella, it also kills off harmless and useful bacteria, such as lactobacillus acidophilus, and active enzymes that help with digestion and absorption of nutrients. Some studies also suggest that pasteurization reduces the amount of vitamins B1, B6, B12, and C contained in milk.

However, this reduction in nutrients is not significant and the risks associated with consuming raw milk outweigh the benefits.

Home on the Grain

Yes. Almost all of the long-chain polyunsaturated fatty acids (PUFAs) in milk are the result of what the cows eat; when cows graze on grass and mixed greens, it improves the fat composition of their milk, equalizing the ratio of omega-6 to omega-3 fatty acids. This ratio is believed to be ideal for human health because it helps raise good cholesterol, lower triglycerides, and reduce inflammation. Research suggests that a cow raised grazing on its natural diet of fresh pasture also has five times more conjugated linoleic acid (CLA), a cancer-fighting fat.

By replacing a cow's grass diet with grain, the ratio of the essential fatty acid in the milk is greatly altered. Milk from commercially raised cows whose feed contains blood meal or bone meal has a more detrimental fatty acid composition and contains little, if any, CLA.

It’s not easy to find milk products from dairies that raise cows on open pastures. Some organic dairy cows are grass-fed, but not all. Nevertheless, consumers are buying organic milk and dairy products in record numbers.