Human milk not only contains less protein than cow’s milk, but the distribution of proteins is also different. A group of proteins that are particularly important in this regard are the immune globulins which carry antibodies and are particularly numerous in the early milk known as colostrum. These globulins contain antibodies found in the mother’s blood and transmit immunity to the newborn infant. When mother’s milk or cow’s milk is ingested, the system is capable of transporting these antibodies directly into the blood-stream via carrier systems, an ability that persists to a lesser extent even in adults. Human milk contains antibodies which differ from those found in cow’s milk and when cow’s milk is substituted for mother’s milk, the immunoglobulins from the cow’s milk will interact with the immune system and this can lead to an allergic reaction. Many allergies can primarily be attributed to milk, and will disappear when milk is removed from the diet.
Allergic disorders are a widespread health problem of particularly infants and young children in the developed world, and according to several population studies, the incidence and severity of these disorders has increased significantly of late.36 Cow’s milk is a major source of allergies and has been implicated in virtually all the common ailments of the respiratory tract. Hay fever, sinusitis, chronic bronchitis, colds, ear infections and even asthma can largely be ascribed to the intake of dairy products.37,38,39 In addition to these ailments, children are prone to diarrhoea, vomiting, constipation, colic, growth retardation, psychological disturbances, eczema and asthma if fed cow’s milk. Allergies need not immediately be apparent and can manifest later in life. Moreover, once an allergic reaction to a substance is manifested, greater sensitivity to other antigens is induced.37 A causative factor in congestive diseases is the ability of dairy products to promote mucus formation, and milk, cheese, butter and cream are the most likely of all foods to promote the build up of mucus.
Cow’s milk also causes colic in infants. The relationship between cow’s milk and colic is well established, and in infants that are breast fed, but also receive cow’s milk, colic is very common. Once cow’s milk is removed from the diet, however, colic disappears in most cases.40 Cow’s milk allergy is frequently the first manifestation of allergy because the proteins in cow’s milk are the first foreign antigens encountered in large quantities in infancy.36 Allergy to cow’s milk is most prevalent at the age of 1 year and has been reported in 2.8% of the general child population, but in infants with atopic dermatitis the incidence of cow’s milk allergy is at least five times that figure.36 Atopic dermatitis is a chronic eczematous skin disease which frequently begins in infancy and probably results from the repeated ingestion of allergins. This in turn leads to frequent scratching and the consequent
trauma induced lichenified lesions. It has been established that casein from cow’s milk causes an increase T-cell frequency and a specific T-cell-mediate immune response to casein can be found in the blood of adolescent and adult patients who suffer from milk-related exacerbation of atopic dermatitis.40
Cow’s milk has been linked to the development of insulin-dependent diabetes (IDD). IDD results from a chronic autoimmune process that can exist for years in a preclinical phase, with the classic manifestations of the disease (hyperglycaemia and ketosis) only occurring after most of the insulin-producing beta cells have been destroyed. There is evidence, that T lymphocytes are a major contributor to the pathogenic process. In this regard, cow’s milk has received much attention because people who were not breastfed or breastfed for only a short period of time are at increased risk of IDD. It is noteworthy, that 100% of newly diagnosed patients with IDD have antibodies to bovine serum albumin. Moreover, the pancreatic beta- cell proteins display substantial molecular cross-reactivity with bovine serum albumin from cow’s milk. IDD can thus be an abnormal response to the foreign protein leading to an immune response to both bovine serum albumin and the pancreatic beta-cell protein. 41
The findings by Cavallo et al 42 of peripheral blood T-cell reactivity to β-casein in half their 47 patients with IDD adds weight to the cow’s milk hypothesis.43 There have been arguments for and against the cow’s milk hypothesis, since IDD also occurs in infants that have never received cow’s milk. However, it has now been conclusively shown that the antigens in cow’s milk are transferred to the mothers milk if she consumes cow’s milk. In a study done on Japanese women it was found that β-Lactoglobulin was transferred to the mother’s milk because it is resistant to acid and enzymatic degradation and if taken orally is absorbed into the system.44 Moreover, there have been reports of infants that are only breastfed and never received milk protein developing allergies to cow’s milk, which was then alleviated when the mothers eliminated dairy products from their diets.44
Finally, the consumption of dairy products has been implicated in intestinal ulcers45 and cancer. Milk consumption in particular has been positively correlated with prostate cancer,5 and in an Italian case study, risk of breast cancer was positively associated with the intake of milk and dairy products.46 For infants, the best food is mothers milk and cow’s milk should be avoided at all costs. Mothers milk will ensure the normal development of infants at every level. It has even been established that the intelligence quotients (IQ) of children that were fed breastmilk are significantly higher than those of children that did not receive breastmilk even after adjustment for differences between groups, mother’s education and social class. 47 For those that have become accustomed to the consumption of milk, the replacement of dairy products with legume, seed or nut milks and creams will provide a more than adequate alternative to milk.