Many people complain that cow’s milk makes them sick, so they switch to vegetable drinks, which have little nutritional value, claiming that their stomach discomfort disappears if they give up cow’s milk. The problem is that they sometimes do not rule out intolerances or allergies beforehand.
Cow’s milk intolerance should be analyzed by its components.
The possible intolerance to cow’s milk is a growing trend but, for this, tests must be performed to rule out an allergy mediated or not by lgE, or carbohydrate intolerance. Looking at the components of milk, one explanation for the improvement of symptoms when giving up cow’s milk may lie in the caseins.
Cow’s milk can be either A1 milk or A2 milk. A2 Milk is milk that, for the most part, lacks any form of protein, the β-casein called A1, which is found in A1 milk. Instead it has, for the most part, A2 casein. This milk was marketed by the A2 Milk Company and is sold mostly in New Zealand, China, Australia, the United States, France and the United Kingdom.
Beta-casein, a milk protein variant that can cause intolerance
A1 and A2 beta-casein are genetic variants of the milk protein beta-casein, although they differ in one amino acid.
Type A1 is the most common type in cow’s milk in Europe (except France), Australia, New Zealand and the United States. There is a genetic test available from A2 Milk Company to determine whether a cow produces A2 or A1 protein in her milk. This test is useful for the company to certify to producers that the milk is not metabolized or converted to β-casomorphin 7.
In a scientific paper published in 2018 Ana Romanowski stated that beta-casein is the major source of protein in milk. However, it was more than 8,000 years ago that the characteristics of beta-casein began to change, with a lone mutation in one of the 209 amino acids in the genetic profile. Breeding and other random events throughout history made A1-producing cows the norm in Europe and, later, in most of the Western world.
What symptoms or digestive disorders can ingestion of milk proteins produce?
There is a difference between A1 and A2 proteins because, by digesting A1 but not A2, beta-casein can trigger the release of the opioid beta-casomorphin (BCM-7) in the small intestine. This BCM-7 has been linked to poor gastrointestinal function, as well as cardiovascular disease, schizophrenia, autism or decreased cognitive functions, in addition to decreased intestinal contractions, increased gas, abdominal pain or suppression of lymphocyte proliferation.
It is important to note, however, that not all studies have been able to highlight that the aforementioned diseases are caused by the release of the opioid beta-casomorphin (BCM-7) when A1 milk is consumed. It is more difficult to demonstrate that it does not produce alterations in intestinal motility, gas, abdominal pain and discomfort secondary to these alterations.
In the face of functional discomfort, Digestive System specialists advise not to suddenly eliminate cow’s milk from the diet and to investigate milk allergies or intolerances, or enzymatic deficiencies in the patient or intolerance to fats, among other possibilities.
Some of the nutritional advantages of cow’s milk are:
- The increased absorption of calcium induced by lactose. This is an important fact, taking into account that bone mass increases until the age of 22, when the maximum bone mass or “peak bone mass” is acquired and that, from that age onwards, it is lost: in women 13% per decade and, in men, 8 to 9% per decade. Bone mass is very difficult to recover, although the rate of loss could be slowed down with some measures, such as the administration of cow’s milk, exercise, vitamin D control, etc.
- More acidic PH of the large intestine. This is achieved with lactose and the prebiotic effect of lactose, which will hinder the likelihood of intestinal infections as well as colorectal carcinoma.
- Greater height of children and adolescents who drink two glasses of milk daily, compared to the height reached by children who do not drink milk, at 20 years of age.
- Less hard stools. Milk with lactose and more fiber is recommended for constipation.
- The lack of lactose intake may decrease some intellectual functions, such as executive functions, compared to children who do take lactose, according to the Brief Test 2 (Behavious Rating Inventory of Executive Functions). Dr. Tormo presented these findings at a congress of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), held in Glasgow, and at the EUROPEDIATRICS congress, held in Dubai in 2019.