The Ingredients in Cow's Milk

Water
The main component of milk is water, around 87 per cent. Water is necessary for the newborn calf and also serves as a carrier for all the other ingredients in milk.

Carbohydrates
The majority of carbohydrate content of milk is lactose. Lactose is a sugar that serves as the main source of energy for the newborn calf. However, for lactose to be digested the enzyme lactase is necessary. All human babies have this enzyme but only some retain it after weaning. In fact, most of the world's population are unable to digest lactose after infancy. That's why lactose is the most common food allergen. The reason for the absence of lactase in many children and adults is evolutionary. No other mammal species needs this enzyme after weaning and therefore, given that it would be redundant, the body simply stops producing it as it's genetically programmed to do so. Drinking milk after infancy is just not what nature intended.

Protein
The proteins in milk can be divided into two categories - caseins and whey proteins. Caseins can be very difficult to digest, are often causing allergies and have been linked to type 1 diabetes. Caseins are so tough they are even used as a basis of some glues! The amount of protein in cows' whole milk is around 3.3 g/100g (3.4g in semi-skimmed milk) while it is only 1.3g/100g in human milk. Moreover, the ratio of caseins to whey proteins is 40:60 in human milk but it is 80:20 in cows' milk. Calves need extra protein because they need to grow fast. Human babies, on the other hand, need less protein and more fat. Not only is the higher amount and wrong ratio of proteins in cows' milk difficult to digest, it also contributes to acidic (unwanted) reactions in the body that may weaken bones.

Fat
While cows' milk always contains saturated fat - and this 'bad' fat is completely unnecessary for humans - it contains only traces or very little polyunsaturated fats that are not only essential for human body but also have a whole range of beneficial properties (eg are anti-inflammatory).
Fat Whole milk (g/100g) Semi-skimmed milk (g/100g) Human milk (g/100g) Total 3.9 1.7 4.1 Saturated 2.5 1.1 1.8 Monounsaturated 1 0.4 1.5 polyunsaturated 0.1 Trace 0.5

Vitamins and minerals
Small amounts of these vitamins and minerals are found in cows' milk: Minerals sodium, potassium, calcium, magnesium, phosphorus, chloride, zinc, iron (very low levels), selenium, iodine and trace amounts of copper and manganese Vitamins retinol (vitamin A), carotene, vitamin E, thiamine, riboflavin, niacin, vitamin B6, vitamin B12, folate, pantothenate, biotin, vitamin C and trace amounts of vitamin D Hormones and Growth Factors Cows' milk contains a cocktail of 35 hormones and 11 growth factors. This cocktail is meant for a calf and is perfectly suited for the growth and development needs of a calf. However, these hormones/growth factors can accelerate cancer growth in a grown-up human body because there's nothing else to grow but malignant cells. Two of the biggest concerns are the oestrogen and insulin-like growth factor 1 (IGF-1) content of milk as both are linked to breast and prostate cancers in humans. Even small increases of IGF-1 raise the risks of several other common cancers including lung and colon cancers. IGF-1 is not destroyed during pasteurisation.

Infectious particles and somatic cells
Dairy cows are prone to disease and due to large numbers of cows on farms and the intensivity of production, diseases spread fast. In the UK, cows suffer from a range of infectious diseases including brucellosis, bovine tuberculosis, foot and mouth disease, mastitis, viral pneumonia and Johne's disease. As a result various contaminants can occur in milk. Mastitis (inflammation of the mammary gland) is very common. It is caused by bacteria and leads to the whole udder or a part of it being inflamed, swollen and very painful. The cow's body responds to the infection by producing white blood cells (somatic cells) that combat the infection in the udder. These cells, together with dead cells and waste products of the inflammation are components of pus and are inevitably excreted into the milk. Milk containing up to 400 million somatic cells per litre is perfectly legal to be sold in the EU.