The type of proteins in milk and the proportion of various proteins, varies depending on the breed of cow and the type of animal (sheep, goat, cow, etc.). One of the major proteins in cow’s milk is casein, the predominant variety of which is called beta-casein. In older breeds of cows, such as Jersey, Asian and African cows (called A2 cows), the beta-casein contains an amino acid called proline.
In newer breeds of cows like Holstein (A1 cows), however, the proline has mutated into an amino acid called histidine.
This is important because beta-casein also contains an amino acid called BCM-7, which is a powerful opiate linked to negative health effects. Well, the proline that exists in A2 cows (the older breeds of cows) has a strong bond to BCM-7, which helps keep it out of the cows’ milk. The histidine in the newer A1 cows, however, has a weak hold on BCM-7, which allows it to get into the milk, and also into the people who drink the milk.
So the theory goes that by drinking milk from A1 cows, which are the predominant cows used for dairy products in South Africa, you’re exposed to BCM-7, which has been linked to:
Neurological impairment, including autistic and schizophrenic changes
Type 1 diabetes
An impaired immune response
Alternatives to Dairy
Raw goat and sheep’s milk is another option, as these types of milk do not contain BCM-7.
One other point, people with healthy digestive tracts do not absorb as much BCM-7. So this is yet another incentive to keep your gut in tip-top condition by eating healthy and getting plenty of good bacteria, either by eating naturally fermented foods or taking a high-quality probiotic -- especially if you enjoy drinking raw milk, and are not sure whether it comes from A1 or A2 cows.
So there you have it, quite a technical explanation but worth the read. I took most of the milk related problems from Dr. Mercola. Worth looking up some of his articles.
Some people, especially children suffering from autism, ADD, sinus, allergies etc are extremely sensitive to any milk product or derivative, to them I would simply say - stay away. There are also studies that show a direct link between the consumption of dairy and the increased incidence of breast and prostate cancer, mostly due to the hormones found in milk, even organic milk, so I would be cautious in any case.
I do not recommend drinking pasteurized milk of any kind because the pasteurization process, which entails heating the milk to a temperature of between 63 to 65 degrees C and keeping it there for at least half an hour. This completely changes the structure of the milk proteins into something far less than healthy.
Pasteurized cow's milk is the number one allergenic food in the country. It has been associated with a number of symptoms and illnesses.
Depending on where you live, A2 milk may not be hard to find at all. In fact, herds in much of Asia, Africa, and parts of Southern Europe still produce primarily A2 milk. If you live in the United States, New Zealand, Australia or other areas of Europe or westernized countries like South Africa, however, you’ll need to look a bit harder.
To find A2 milk, the type that has not been associated with illness and instead appears to have numerous health benefits, look for milk that comes from Jerseys, Asian and African cows. The best way to do this may be to get to know a farmer directly and find out what type of cow is used. And as always, stick to milk that is raw, NOT pasteurized.