Milk: Does it really do a body good? Most of us are familiar with this advertising catchphrase. It's also one of the most parodied slogans in history. A quick headline search reveals a slew of send-ups, ranging from sarcastically simple "Milk: It does a body bad" to the even more straightforward "MilkSucks.com." Whether or not we should consume dairy products is one of the most common dietary issues in the news, yet there still doesn't seem to be a definitive answer. Let's take a look at the pros and cons of dairy and hopefully help you shed a little light on whether or not you want it as a part of your diet.
Conclusion
I didn't accidentally paste the end of the article into the second paragraph; I just thought it would be best to get this out of the way right up front. Whether or not humans should consume dairy—specifically cow's milk and all its byproducts—is, as you might surmise from the intro, a volatile issue. Opinions tend to be black or white and served up with heaping scoops of passion. But passion tends to come from emotion, not science, and a lot of dairy lore seems to be based on anecdotal conjecture rather than investigation and analysis.
This doesn't mean that there's no science involved in the debate—far from it. A search of the National Library of Medicine shows that more than 25,000 studies have been done on dairy, apparently none of which can give us any sort of consensus on its health effects in humans. What all these studies do show is that dairy products are neither going to kill us or help us live forever. We can consume them and be healthy, but we also don't need to consume them to be healthy.
Dairy can be a fine addition to one's diet, but that doesn't mean it's right for your diet. You certainly don't need as much as the National Dairy Council recommends, but dairy also needn't be vilified more than any other type of food. As with most foods these days, there are issues, particularly when it comes to the way humankind seems compelled to continually "improve" them. But there are also individual considerations that should be assessed, and this article will address them.
The Bottom Line
In keeping with our reordered approach to the dairy story, let's look at the most simple aspect of dairy: its nutrient profile. Of course, this varies according to product, but most dairy-based foods are a good source of protein. Some, like yogurt and milk, have carbohydrates. And in their natural states, all dairy products contain fat and are great sources of enzymes. Most dairy products, especially those with the fat removed, would appear to be a fine source of nutrition.
There is little reputable science to dispute that the dairy proteins casein and whey have excellent biological value profiles. Dairy fats are generally unhealthy, have high percentages of saturated fats, and should be limited in a healthy diet. But some dairy fats, mainly from certain cheeses, contain enzymes that make them a potentially beneficial part of a healthy diet, if consumed in moderation. Dairy's carbohydrate source, lactose, has been the subject of a lot of scrutiny, but appears to be fine for most people, especially in its natural form. As we go on, we'll examine the potential benefits and pitfalls of dairy consumption.
The Issues
Too much fat. As stated above, dairy products contain a lot of fat. Your diet should consist of around 20 to 35 percent fat, but very little of this should come from animal sources. The anti-dairy movement claims an association between consuming dairy and heart disease as a reason to steer clear, but it makes little sense to single out dairy as opposed to, say, meat—or pretty much anything you can buy at your corner 7-Eleven®. Most dairy products are available in low- or no-fat options where the fat is reduced or removed. Anyone for whom dairy products provide a major percentage of their daily calorie intake should definitely switch from full-fat to reduced-fat or nonfat dairy products. There are some concerns regarding protein-to-fat ratio and calcium utilization, though—read on.
Aren't most of us lactose intolerant? Some people have problems digesting dairy products, which can lead to an unpleasant gastric condition usually referred to as lactose intolerance. The exact definition of lactose intolerance, as well as its specific details, remain under debate, but the condition appears to result from the pasteurization of dairy products, which kills the enzymes that aid the body's digestion process. Milk and yogurt in raw form don't seem to cause lactose intolerance. Regardless, the numbers here are skewed; anti-dairy pundits will often claim that the percentage of people who suffer from lactose intolerance is actually a majority of the population. Other studies seem to peg the number at closer to 20 percent. One constant is that those from cultures who have historically consumed a lot of dairy are not affected as much as those who aren't.
Lactose intolerance isn't a dangerous condition, but it can cause considerable discomfort. If you do suffer from the condition, you might be interested to know that millions (if not billions) of people worldwide are perfectly healthy without consuming any dairy at all. Just be wary of replacing all the dairy in your diet with any other single food source, especially soy. Many dairy substitutes are soy based, and too much soy in your diet can be problematic. (Refer to Denis Faye's article "Soy: Magic Bean or Tragic Bean?" elsewhere in this newsletter.)
Does dairy cause a loss or gain of calcium? This is one of the more interesting controversies. The dairy industry champions itself as a leading provider of calcium. The anti-dairy folks say that exactly the opposite is true. Which (if either) is right?
The pro side is simple: They say dairy products contain a lot of calcium, and numerous studies show the importance of calcium in our diets. The con side is more complex. Some science suggests that the high protein-to-fat ratio of nonfat dairy sources, along with an abundance of vitamin A, somehow reduces the body's ability to utilize calcium. This isn't exactly confirmed by the said studies, which actually showed "no decrease in instances of osteoporosis."
Does dairy cause osteoporosis? This is a fairly common claim cited by a wide variety of Internet sources. Most of these sources cite rather dated research, including a Harvard study published in the American Journal of Public Health way back in 1997, which claimed a correlation between female milk drinkers and hip fractures. However, newer research, such as a study in the April 2011 issue of the Journal of Bone and Mineral Research, found no connection at all between dairy consumption and hip fractures.
While neither study bodes well for the dairy lobby, it seems a bit odd to make any assumptions based on one dietary staple, considering that the largest piece of this puzzle is being left out altogether: exercise. In the last couple of decades, caloric increase across the U.S. has risen only around 3 percent, whereas the amount of exercise we get has dropped a whopping 20 to 25 percent. When you consider that the primary reason elderly people break their hips in routine falls is due to loss of muscle that protects the bones, it doesn't take a MENSA member to suspect that lack of exercise might be a culprit.
Dairy helps you burn body fat. From the flip side of weird science came a 2003 study out of the University of Tennessee that got a lot of publicity; it showed that those who consumed dairy products lost more body fat than those who supplemented with other types of calcium. But before you decide that yogurt should suffice for all of your calcium needs, consider that the study didn't involve an even playing field. The subjects were on a reduced-calorie diet and the dairy group was given twice the amount of calcium the supplement group received. The study was funded by Yoplait®; feel free to draw your own conclusions.
Regardless, two conclusions you could draw are that calcium is beneficial to your diet, and that you can use the type of calcium you get from dairy products to satisfy your body's need for calcium.
Dairy causes cancer. Much of the concern over dairy and its potential to cause cancer comes from the book The China Study by T. Collin Campbell. In it, Campbell cites studies in which casein protein caused tumors in rat. While this is valid research, it needs to be taken with a grain of salt, given that humans and rodents have very different physiologies and these studies administered massive, concentrated amounts of the substance—far more than a human would ever consume in a day.
Dairy is filled with hormones. This is a major, well-documented issue involving how our nation's dairy cows are raised. The FDA assures us that dairy farmers are only allowed to "dope" cows with safe drugs. Many people and organizations disagree with this statement. This is a subject that is too broad to cover adequately in one short article. It's a debate that colors nearly every food-related decision most people make. It's important to know that on the subject of dairy, we do have choices. We can choose organic options, or buy our dairy products from a local farm or farmer.
Which is better: raw or pasteurized? Nearly all pro-pasteurization literature comes from the National Dairy Council or U.S. regulatory agencies. On the other side, there's a passel of independent information that cites the virtues of raw dairy products.
Dairy, in its raw form, is healthier (provided it comes from healthy cows). In fact, most raw-dairy advocates claim that lactose intolerance is a nonissue for consumers of raw dairy products because the lactose in these items is broken down by the enzyme lactase, which is killed during pasteurization process—a process raw dairy products don't go through. Another issue is that cows aren't always healthy. When cows are unhealthy, it's common for deadly bacteria, including E. coli, to show up in the dairy products produced from their milk. Since pasteurization kills both bad and good bacteria while preserving much of the nutrient value, it's championed as the better alternative by government agencies charged with safeguarding public health—and promoting dairy consumption.
Is organic better? Again, nearly all of the anti-organic literature comes from the National Dairy Council or U.S. regulatory agencies. This is, of course, because it's their job to ensure us that all dairy is healthy and safe to begin with. And again, there are plenty of studies supporting organic as being preferable.
The verdict can again come down to some common sense. Organic standards require that cows live in better conditions and eat better food. We know that when we live better and eat healthier food, we are healthier. We can suppose that this is also true about cows. The next assumption would be that eating food produced by a healthier organism would be healthier. If this makes sense, it's logical to conclude that organic is better.
There are many healthy societies and cultures that don't use dairy. This isn't exactly true. Yes, there are many healthy people who don't consume dairy, but dairy (when you include all animals, not just cows) has been consumed by most cultures since ancient times. The most commonly cited cultures that don't consume dairy are in the East, mainly China, but historically, much of China was heavily dependent upon dairy. In fact, the northern regions and Mongolia have used yogurt as a nutritional mainstay for centuries.
An analysis of the cultures that currently use little or no dairy yields mainly a list of poorer and less well-nourished cultures. And due to the socioeconomic climate of these regions, it seems unfair to cite lack of dairy as a reason for these cultures being malnourished. There are many examples of healthy, well-educated individuals who are perfectly healthy without dairy, and many decidedly healthy cultures, such as the Japanese, use much less dairy than those in Western Europe and the United States.
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