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What's in milk?

Adverts for dairy products are very inventive but rarely tell you actual facts. We all know milk contains calcium but what else is in it? And how does it affect your health? Here are the facts on nutrients in milk:


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.


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 (about two thirds!) are unable to digest lactose after infancy. That’s why lactose is the most common food allergen and so many people are lactose intolerant.

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.


The proteins in milk can be divided into two categories – caseins and whey proteins.

Caseins can be very difficult to digest, are often causing cow's milk allergy 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 cow's 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 cow's milk difficult to digest, it also contributes to acidic (unwanted) reactions in the body that may weaken bones.


While cow's 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).


Whole milk (g/100g)

Semi-skimmed milk (g/100g)

Human milk (g/100g)

















Vitamins and minerals

Small amounts of these vitamins and minerals are found in cow's milk:

sodium, potassium, calcium, magnesium, phosphorus, chloride, zinc, iron (very low levels), selenium, iodine and trace amounts of copper and manganese

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

Cow's milk naturally contains a cocktail of 35 hormones and 11 growth factors. This cocktail is meant for a calf and is perfectly suited for its growth and development needs (a calf grows into an adult size cow in just one year).

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 oestrogen and insulin-like growth factor 1 (IGF-1) 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 breast, prostate, lung and colon cancers. IGF-1 is not destroyed during pasteurisation. For more information on this subject see Cancer.

Infectious particles and somatic cells (pus)

Dairy cows are prone to disease and due to large numbers of cows on dairy farms and the intensity of production, diseases spread fast. In the UK, cows can 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 udder) 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 (neutrophils) that combat the infection in the udder. These cells, together with dead cells (all these cells are called 'somatic 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.


For references and more information, see the White Lies report.


Find out more


This report combines the findings of over 400 scientific papers from reputable peer-reviewed journals such as the British Medical Journal and the Lancet.

How to build healthy bones and what really matters in the prevention of osteoporosis.

This guide will provide you with all the theoretical and practical information on healthy bones you need.


A handy fact sheet summarising everything you need to know about calcium and your diet.

If you'd like a paper copy, please order it here.

If you'd like a paper copy, please order it here.