Vitamin A for cows as an aid against milk allergy
According to health experts, around six million people in Germany alone suffer from a food allergy. Cow's milk is one of the main triggers for infants and children. Researchers from Austria have now found that the allergic reactions could be prevented by sufficient vitamin A in animal feed.
More and more people suffer from a food allergy
Food allergies have been increasing for many years. According to estimates by the German Allergy and Asthma Association (DAAB), around six million people are affected in Germany alone. According to the experts, cow's milk is one of the main triggers for food allergy in infants and children. A cow's milk allergy usually disappears into adulthood, but it increases the risk of further allergy diseases. As a study by Austrian researchers now showed, the allergic reactions could be prevented by sufficient vitamin A in animal feed.
Cow's milk allergy usually subsides until adulthood
The question of whether milk is healthy or harmful has been a hot topic among experts for years.
There are studies that conclude that milk is healthy because it can protect against osteoporosis, among other things, through the calcium it contains.
However, there are also studies that indicate that milk may promote diseases such as asthma or diabetes.
In addition, some toddlers develop a cow's milk allergy, which usually resolves into adulthood, but increases the risk of further allergy diseases.
Allergic reaction can be prevented
However, the allergic reaction can already be prevented by the good interaction of two milk components.
This was shown by a study by the inter-university Messerli Research Institute of the Vetmeduni Vienna, the MedUni Vienna and the University of Vienna.
If the important milk protein Bos d 5, also beta-lactoglobulin, and the vitamin A metabolic product retinoic acid in cow's milk combine, the immune system does not become active against the protein.
The results of the study were recently published in the scientific reports.
Up to five percent of children have a real milk allergy
According to a communication from the University of Veterinary Medicine Vienna, a real milk allergy occurs in about three to five percent of children in Europe, less often in adults.
In contrast to the lactose intolerance (milk sugar intolerance), which is often confused with the disease, in which only lactose is poorly digested due to the lack of lactate enzyme, the immune system itself reacts in this case with a defense mechanism against milk proteins.
Special immune cells are formed that produce antibodies against milk proteins and thus trigger a potentially much more dangerous allergic reaction.
The Austrian researchers have now been able to show that this can prevent the components of cow's milk itself.
The key is that the milk protein beta-lactoglobulin relevant for allergic reactions, retinoic acid, a metabolic product of vitamin A, is almost in your pocket.
For this, however, the cows must be adequately supplied with the vitamin, for example through a lot of green fodder.
Defense against milk proteins
If toddlers develop an allergy to cow's milk, special immune cells are formed in their bodies with Th2 lymphocytes, which produce antibodies that are directed against the milk proteins as the body's own defense.
One of the most important of these so-called milk allergens is the protein Bos d 5 or beta-lactoglobulin. This belongs to the protein family of lipokalins.
"This special protein family has molecular pockets that can hold small molecules such as retinoic acid, which is a metabolite of vitamins A," explains first author Dr. Karin Hufnagl.
"Our studies showed that the" empty "milk protein supports the activation of Th2 lymphocytes and thus triggers an allergic reaction chain," says Hufnagl.
However, if the retinoic acid is in your pocket, the immune cells react moderately, without an allergic immune reaction.
"Adequate loading of the milk protein could prevent toddlers or adults from becoming sensitized and developing a milk allergy," concludes study leader Erika Jensen-Jarolim.
Effects of a cow's milk allergy
According to the researchers, milk, and especially cow's milk, is an essential food for most people.
However, it is a risk for allergy sufferers, as it can cause swelling of the mouth or mucous membranes, diarrhea or the worsening of neurodermatitis.
The latter is also the reason why health experts advise people to restrict milk products significantly.
After drinking cow's milk, some sufferers also experience abdominal pain, skin reactions such as wheals, flatulence and tiredness.
In rare cases, cow's milk can also cause an allergic shock. In addition, a cow's milk allergy carries the risk of other allergic diseases, such as atopic eczema or allergic asthma
Increased administration of green fodder
"A sufficient supply of milk producers, i.e. cows, with vitamin A could counteract this effect of possibly converting a harmless food protein into a milk allergen," says Hufnagl.
However, it is questionable whether the positive effect of vitamin A shown in the study can also be achieved through food additives.
"Artificially supplementing food with vitamins may not have the same effect as natural ingredients and is likely to result in an inadequate loading of the milk allergen," says the researcher.
“It is therefore necessary to supply the animals with a corresponding amount of vitamin A when they are kept or fed. This can be achieved, for example, by adding more green fodder. Corresponding follow-up studies still have to be carried out. ”(Ad)