Is milk human food?
Consuming milk in adulthood, especially from other animals, is an interesting thing. On one hand it seems to be entirely unnatural, after all we are the only mammals doing it. On the other hand, milk is very nutritions ( protein, calcium, vitamin D, phosphorus, potassium, vitamin B12 and other vitamins and minerals) and has many benefits to human health But do the benefits (and its deliciousness) outweigh the harm?
Milk causes inflammatory and allergic responses in most people
USA Today reported in 2009 that about 60 percent of people in the world can't digest milk, suggesting that not being able to process milk (lactose intolerance) is not a disease or condition but actually the norm! The article, refers to the minority who can handle milk as lactase persistent, the exception to what's normal. Based on these numbers and assuming they are accurate, there is no doubt we aren't really designed to consume milk beyond childhood and much less from other animals.
Dairy cows are treated with antibiotics and hormones (and therefore their milk!)
Now this is no news… Dairy cows in the U.S. are normally treated with a variety of hormone supplements, some naturally occurring in cows and humans and others not so much. Their benefit, of course has nothing to do with our health or nutrition but with the increase in milk production, growth and development – probably not something you would want in your body. Besides, cows treated with hormones have a higher incidence for infections and diseases (wouldn't we as well by consuming it?). So guess what... they get treated with antibiotics, which have been known to lower the body's immune response. Although no studies were conclusive, many link milk from hormone and antibiotic treated cows with certain cancers.
The milk available to you on shelves is no longer real milk: pasteurization and man-made alterations
Pasteurization was a great thing a couple of hundred years ago when sanitary conditions were poor and the living conditions of dairy cows were worse than todays' dairy factory farms, if you can believe that worse is possible. But if the cows live in appropriate, clean conditions and the milk is tested for the presence of any harmful bacteria before consumption, there is really no need for pasteurization other than to increase milk's shelf life. The main problem with pasteurization is that most of the beneficial properties of milk are entirely or partially destroyed during the process. And according to this article, raw milk has many benefits that are reduced or absent in pasteurized milk, such as enzymes that damage pathogens and breakdown bacteria, proteins that increase iron absorption, antibodies that strengthen the immune system and more.
Is consuming dairy a matter of survival of the fittest?
A group of researchers exploring the origin of lactase persistence found evidence that a genetic mutation was present in farmers 7,500 years ago in Europe, allowing them to unproblematically drink milk beyond childhood and that most Europeans today present this same abnormal ability to produce lactase and digest milk with no problems. Following this thread, would the body's natural production of lactase in some humans be a sign of evolution and adaptation toward tolerating a wider range of foods, especially something as nutritious as milk? Food for thought.
Should you cut milk from your diet if you feel fine?
I don't think that anyone really knows the answer to this question at this point. There is research to back up its benefits and its harms alike, but nothing conclusive on whether milk is fit for human consumption after development.
If you haven't been diagnosed with lactose intolerance and haven't experienced any of the symptoms, the only way you will really find out if milk is good or bad for you is by eliminating it from your diet for at least one month and assess the difference in how you feel, if any. And if you notice no change for the better, you just might have inherited milk adaptability from those European farmers of 7,500 years ago.
At the end, isn't everything bad for us for one way or another?
In a way, yes… All food groups have their own toxic abilities and issues – just think of how animals are raised and massed produced for instance. And all plants have their own levels of anti nutrients that are bad for us. But at the end of the day, what really matters is what foods do you have access to that will give you the most amount of nutrition in the least amount of calories and harmful substances. And moreover, which foods are available to you in their natural and undisturbed form (animals, fruits and veggies included).