Dairy in America is in a really strange state. For the generation of my parents (people who around 50), their entire childhood Dairy meant cow's milk. That was the only option. Things have changed a bit, in that these days we can more easily get dairy derived from goats, or even fake dairy derived from soy. In more recent years, people have once again began acknowledging that milk can (and should) be a part of a healthy diet.
According to some studies, however, Lactose intolerance is an incredibly common problem, particularly among older people. However, I think that this has more to do with the way in which we consume milk, than anything innate in Milk. And I'm pretty sure I'm not just blowing smoke here. My wife had, for many years, complained of lactose intolerance. She suffered through it out of love for Cheese and Ice Cream, as I would likely have.
After some badgering, I convinced her to start taking Lactase supplements, which helped quite a bit. The interesting thing is, since we switched to drinking whole milk, she hasn't needed it. It turns out that lactose is more concentrated in the liquid portions of milk, and therefore dairy with a higher fat content, is going to naturally have less lactose to be processed. But that's far, far from the whole story.
Ultimately, the problem isn't that most Americans tend to buy 2%, 1%, or even Skim milk instead of whole milk (which usually has under 4% milk fat), the real problem, is that we drink pasteurized milk.
That's right, pasteurization is absolutely destroying our ability to process milk. My father has even commented on the fact that, when he was younger and they were drinking milk that had fat floating on it's surface, he never had digestive issues with it. Now, one could argue that this is related to age, since most people developing difficulty with milk with age, but among European Americans, the incidence of lactose intolerance tends to be around 10-15%. There is a biologic predisposition in mammals toward the body stopping production of the lactase enzyme, however, it seems that among peoples who consistently have access the lactose, the gene is far less likely to shut off. Even among the Japanese, who typically developed a near 100% lactose intolerance after weaning, are starting to become happy milk drinkers, even into adulthood. I'm no geneticist, but it seems that the gene is generally turned off when the lactase is no longer needed. Makes sense, but I'd like to see more research on the subject, myself.
Still, even among people who consistently enjoy Milk products, it seems that lactase production does slow with age. That genetic predisposition, poking it's head up again. I believe this can be linked directly to the pasteurization of milk. But, let's start at the beginning while we form this argument.
Pasteurization was 'invented' by Louis Pasteur in 1862. I put 'invented' in quotes, because people had been performing the basic process for literally thousands of years by this point, but Pasteur did codify the scientific basis for the practice, and that does deserve some respect. Pasteurization is basically cooking. It's raising the temperature of food to the point where various microorganisms can no longer survive, or at least so that enough don't survive that what's left can be easily dealt with by the bodies natural immune system.
Now, heat does break apart the microorganisms, but it also breaks apart a lot of other chemicals in the food. This changes the way the food tastes (sometimes for the worse), and can break apart proteins and other structures. It changes the chemical structure of the food, and this is one potential problem with the process (but it's fairly minor in my opinion). And with milk, where 'ultra-pasteurization' is often used, this process involves quickly taking the dairy from ambient temperature to 250 degrees Fahrenheit, and back down within a fraction of a second.
So, this is meant to kill disease right? What could possibly be wrong with that?
The stated purpose is honorable, I'll agree. The problem is that pasteurization doesn't just kill the bad microbes, it also kills a lot of the good ones. Including, in milk, some bacteria that naturally help the body break down the lactose. But, 1862 was at the height of the industrial revolution. More people were moving into the cities, and living denser than they ever had before. The lack of refrigeration required perishable food sources, including dairy, to be close to the cities. People didn't truly understand at that time what was responsible for causing disease, and standards for food safety were non-existent.
Cow got sick, and it's milk contained blood or pus? That didn't matter, ship it to the waiting customers. Cows all covered in shit and it's falling into the buckets as they get milked? No problem! If you're luckily, the milker will pick it out quickly. Contamination was common, partially due to ignorance, partially because the customers didn't bother to ask, and the Dairies weren't being held accountable.
This just isn't true anymore. In this country we have the Food and Drug Administration who has set out standards for food production because consumers weren't able to make an educated choice for healthier products. However, even the FDA occasionally gets the science wrong. The FDA, as recent as 2004 has still been against Raw Milk. Now, I'm of the opinion that this is largely due to the Dairy Lobby in this country, who tends to work really hard to stop people who don't want to play by their rules.
Luckily, the FDA hasn't tried to completely stop the sale of Raw Milk. They've left that power up the individual states. In Washington, it is possible to get licensed to produce Raw Milk commercially (interesting fact: Raw Milk in Washington must have a lower bacterial content that that which is allowed in already pasteurized milk). Idaho technically could have a Raw Milk dairy, but the state hasn't licensed anyone for decades, and that is seen as unlikely to change. However, the FDA has banned interstate commerce of raw milk, so a Washington Dairy can't transport it's product to Idaho for sale. Which is too bad, because the local organic food Co-op here in my area, is in Moscow. But, if you own your own cow, or participate in a Cow Share, you can still have access to Raw Milk pretty much anywhere in the US.
As I'm not a Food Scientist, I'm going to defer to some people who are. The Weston A Price Foundation has begun the Campaign for Real Milk (a cute play on Britain's Campaign for Real Ale from years ago), and that site has tons of information on why you should want raw milk, and how to get it in your state. They suggest reading 'Medical Maverick' Dr. William Cambell Douglass II's book, The Milk Book: The Milk of Human Kindness Is Not Pasteurized. I suggest to do so as well.
There is big, big business in the milk market. The factories which pump out the pasteurized milk, are owned by a small group of companies, and they can sell their product hundreds of miles away from where they bottle it because of pasteurization and refrigeration. And the US Government has essentially forced this system on us since the 1930s. Raw Milk is more expensive, no doubt about that, but mostly that's because so few people are producing it. If we move to a less centralized dairy system where Raw Milk is more economically feasible, the price will drop. Will it drop to what we're paying for milk today? Maybe not, but since it won't have to travel as far, or go through as much processing...it just might.