Japanese are genetically unfit for milk! A2 milk, the next generation of milk that “doesn’t make your stomach rumble,” is finally available in Japan.

A2 milk” has spread from overseas and is beginning to attract attention in Japan

Have you ever avoided drinking cow’s milk because it makes your stomach ache or you get diarrhea easily, or have you been careful about when you drink it? For those who think milk is not suitable for them, there is good news: A2 Milk, a next-generation milk that is easy on the stomach, is attracting attention.

A2 milk has been popular in New Zealand, Australia, and other countries for more than 20 years, and demand for A2 milk is gradually increasing in Japan as well.

Professor Takashi Koumoto of Tokyo University of Agriculture, who has been involved in research on A2 milk since 2007, says, “When you drink cow’s milk, your stomach gets upset and you feel hungry, so we have been working on A2 milk.

The difference between A2 milk and regular milk is the type of beta-casein, a type of protein contained in milk. beta-casein is determined by the genes possessed by individual cows, and there are two types: A1 and A2.

In a normal dairy farm, A1 cows, A1A2 cows, and A2 cows are raised together. Therefore, milk produced there contains a mixture of A1 and A2 type beta-casein. This is common milk.

Milk from cows with the A2 gene contains only A2-type beta-casein. This is called “A2 milk.

The term “A1 type” and “A2 type” is difficult to understand, but it is the same as the human blood types, A, B, and AB.

In other words, milk squeezed from only pure A2 cows is called “A2 milk. Originally, all β-casein in milk was of the A2 type, but during the process of domestication of cows, the gene mutated and A1 type β-casein was born. It is speculated that this spread to various dairy breeds, especially Holsteins.

Most Japanese are genetically predisposed to “lactose intolerance.

Lactose intolerance” is a condition in which drinking milk causes a stomach ache or diarrhea. This symptom is caused by a decrease in the activity of lactase, a lactose-disintegrating enzyme that breaks down the lactose contained in milk, resulting in an inability to digest and absorb it properly.

A1 beta-casein is thought to be one of the causes of indigestion. 67 of the 209 amino acids that make up beta-casein are different between A1 and A2 types. It is only one amino acid difference, but only type A1 beta-casein is said to lead to abdominal discomfort.