What’s in Dairy & Do We Need It?

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 what’s in milk.


The main component of milk is water- around 87 per cent and it’s even more in skim milk, over 90 per cent. Water is necessary for the newborn calf and also serves as a carrier for all the other ingredients in milk. When dairy proponents criticise plant milks for containing a lot of water, they’re conveniently forgetting that dairy milk shares that characteristic too!


Milk naturally contains sugar – lactose – about 5g per 100ml. 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 so many people are labelled as 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, often cause 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 cow’s 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.


The majority of fat in milk and dairy products is saturated. Even though low-fat milk products contain less fat overall, the fat in them is almost all saturated. This ‘bad’ fat is completely unnecessary for humans and increases the risk of many diseases including heart disease and stroke, diabetes, metabolic syndrome and has been linked to several types of cancer. Some dairy products, such as cheese, are the biggest saturated fat contributors in Western diets and have been blamed for the current obesity epidemic.

Milk contains only tiny amounts of polyunsaturated fats that are not only essential for the human body but also have a whole range of beneficial properties (eg are anti-inflammatory). These are abundant in plant foods and some plant milks are also a good source.

Vitamins and minerals

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

  • Minerals: sodium, potassium, calcium, magnesium, phosphorus, zinc, selenium, iodine and trace amounts of copper and manganese
  • Vitamins: vitamin A, vitamin E, thiamine, riboflavin, niacin, vitamin B6, vitamin B12, folate, pantothenic acid, biotin and trace amounts of vitamin D

Sounds good? Think again – the amounts are small, aside from calcium, and you can get all of these from better, healthier and more ethical sources. The truth is, the dairy industry are great at exaggerating but there’s nothing essential about milk.


Cow's milk naturally contains a cocktail of 35 hormones and growth factors, including IGF-1 (insulin-like growth factor 1), oestrogen and progesterone, adrenal, pituitary, hypothalamic and other hormones. All these are meant for a calf and perfectly suit his or her growth and development needs (a calf grows into an adult size cow/bull in just one year).

However, these hormones can accelerate cancer growth in a grown-up human body. Certain types of cancer cells are sensitive to hormones and respond with faster and more aggressive growth.

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 the White Lies report.

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 ofpus and are inevitably excreted into the milk.Milk containing up to 400 million somatic cells per litre can be legally sold in the UK.

In the USA, the upper limit for somatic (pus) cells is 750 million and there’s a lot of pressure on the UK and EU to raise the limit – with Brexit, this may happen in near future.

FAQs — Health and Nutrition

What are the best calcium sources? What's important for bone health? And are there hormones in milk?

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