What is A2 milk?

Country Smallholding - - Processors -

TWO MA­JOR pro­tein groups are present in cow’s milk — ap­prox­i­mately 82% of pro­tein is ca­sein and 18 per cent whey pro­tein. Ca­seins are a group of pro­teins and beta ca­sein is the sec­ond most abun­dant pro­tein. The beta ca­sein group has two com­mon vari­ants: A1 and A2. Most milk con­tains a mix­ture of these pro­teins. Ap­prox­i­mately 60% of the beta ca­sein is A2, and 40% is A1. The pro­por­tion of A2 and A1 beta ca­sein in milk varies with dif­fer­ent breeds of dairy cat­tle, but A2 milk con­tains only A2 beta ca­sein.

Be­fore do­mes­ti­ca­tion, cows pro­duced the A2 beta ca­sein pro­tein and not A1. A nat­u­ral gene mu­ta­tion oc­curred in Hol­steins 8,000 years ago, re­sult­ing in pro­duc­tion of the A1 beta ca­sein pro­tein in this breed. In gen­eral, milks from Guernsey and Jersey cows, Asian herds, hu­man milk and oth­ers (sheep, goat, don­key, yak, camel, buf­falo, sheep, etc) con­tain mostly A2 beta ca­sein.

Milk from Hol­stein Friesians con­tain mostly A1 beta ca­sein. Be­cause Hol­steins are used to ge­net­i­cally im­prove the pro­duc­tion of other dairy cat­tle breeds, the A1 beta ca­sein vari­ant be­came dom­i­nant in milk. But dairy herds in much of Asia, Africa and parts of south­ern Europe re­main nat­u­rally high in cows pro­duc­ing A2 milk.

More than 50% of the Jersey breed car­ries the A2 beta ca­sein vari­ant, but with con­sid­er­able vari­a­tion among the herd, and more than 90% of the Guernsey breed car­ries the A2 beta ca­sein vari­ant. As this is ge­netic, it gets passed onto off­spring — you can there­fore breed for an en­tirely A2 herd once you have tested cat­tle and culled/bred as ap­pro­pri­ate. Why is this im­por­tant? Many peo­ple be­lieve that they are lac­tose in­tol­er­ant and give up dairy en­tirely, but some of this group may ac­tu­ally have an in­tol­er­ance to A1 beta ca­sein.

Drinking A2 milk and its dairy prod­ucts is un­der­stood to re­duce bloat­ing and in­di­ges­tion (di­ges­tive dis­com­fort) caused by A1 milk con­sump­tion.

A2 milk con­tains the same amount of lac­tose as non-A2 milk so, in clin­i­cally di­ag­nosed cases of lac­tose in­tol­er­ance, A2 milk will not pro­vide the ben­e­fits that lac­tose-free milk of­fers.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.