A2 milk products can help prevent allergy and atopic eczemaWhy is A2 milk handled differently by our bodies, and why does this matter to allergic or atopic individuals?

I used to think there was not much difference in different cow’s type of milk. But there is. They break down into different components.

One can now buy A2 milk in supermarkets, sourced in UK from the Guernsey breed of cow. A1 and A2 refer to different milk protein chains made by different breeds of cow. Supermarket pooled and homogenised milk in UK and Europe contains mostly A1 protein, which breaks down into peptides (pieces of protein) that can and often does trigger allergies. Asian and African cows, and some in France and Switzerland, and all cows in New Zealand produce the A2 protein milk.

One of the most damaging bits of protein broken down from from A1 milk appears to be BCM-7, but this is not not produced at all from A2 milk. This chain of seven amino acids is biologically active in some damaging ways. Thus far, BCM-7 is implicated in a range of immune and histamine-based reactions, which can have far reaching effects, on the brain as well as the skin, and even the pancreas. BCM-7 has been found to be linked to type 1 diabetes in children, which is an auto-immune disease of the pancreas, in which the insulin producing cells are destroyed. There is a definite link to behavioural problems in children, and may be one of the causes of autism. There is also a link with histidine and histamine production, and it is known that anti-histamines are rather ineffective in children with atopic eczema, despite the large quantities of histamine produced in the skin of sufferers. The BCM-7 produced when ordinary milk is broken down may be the key behind all this histamine. And often, parents are told to try a dairy free diet in difficult or resistant eczema in their children. But perhaps it is all down to A1 milk, and kids should continue to have A2 now this is readily available. I have made up a short pdf for you to print at home which summarises the difference between A1 and A2 in terms of this damaging peptide chain.

A1 vs A2 milk 1

Parents should at least try a six month period for their children, switching from homogenised A1 milk (all normal supermarket milk in UK is A1) to A2 milk. This is now sold by the A2 milk company, using milk from UK Guernsey breed of cows, where the herds are entirely A2.

You could also seek out a farm shop near you if you are in the Southeast of UK, and ask if they have Guernsey herds producing A2 milk, or go to the websites which sell it direct to the public.


Abel and Cole also supply organic A2 Guernsey cows’ milk


and the range of brown cow organic yoghurts


It should be noted that goat and sheep milk are also A2 milk protein (like breast-milk)


The big difference between A1 and A2 milk protein is how they break down into component protein parts, called amino acids, and what happens to these building blocks in the body. Histidine (related to histamine) can be broken down by elastase into BCM-7, which is a damaging molecule, implicated in a range of immune disorders.

BCM-7 is the trigger for inflammatory disorders, both within the gut, and at distant sites like the skin. The A2 milk company is careful not to attach claims which remain contentious.

There have been many scientific studies showing a link between Histidine and BCM-7 breakdown products and various clinical conditions, although not all researchers are convinced, as this paper from Truswell shows. I would not be the first person to point out the rivalry between Australian researchers and those from New Zealand (who have been convinced for a long time). I do not know how much bias exists in the scientific research community, but it is possible that confirmation bias plays a role in what conclusions people draw to a particular scientific paper.

Cows’ milk A1 & A2 type beta-casein protein digesion

The A2 milk case: a critical review