Vitamin A in animal feed could potentially protect against milk allergy
- a condition that may cause a variety of different symptoms
It appears that an increasing number of people suffer from some kind of milk allergy. Science is primarily focused on lactose intolerance, a condition that is caused by a deficiency of a digestive enzyme. The allergic reactions normally show almost immediately after ingesting dairy products. Allergy as such occurs when the immune system overreacts to various milk proteins. The allergic reactions occur in many different places in the body, and several days may pass before the symptoms are noticed. Now, researchers from the University of Veterinary Medicine in Vienna have demonstrated how animal feed that is enriched with vitamin A may prevent allergic reactions caused by milk protein. It also seems that the quality of milk has changed, and that in itself may be a contributing factor to hypersensitivity.
Nature has endowed all children with an exceptional ability to break down and absorb lactose in their digestive system. However, as they grow up, this ability is reduced more or less. The majority of people worldwide is unable to digest lactose from cow’s milk, and the percentage of people with lactose intolerance varies geographically from a few percent (in Europe) to nearly 100 percent (in Asia). People with lactose intolerance lack in their small intestine an enzyme called lactase. Under normal conditions, lactase breaks down lactose so the small intestine can absorb it. However, because of the absence of this enzyme, lactose continues in its undigested form to the large intestine where it binds fluid and causes diarrhea. Intestinal bacteria initiate a fermentation process that causes abdominal pain, stomach rumbling, and flatulence.
With fermented dairy products, the added lactic acid bacteria convert part of the lactose to lactic acid, which is why yoghurts contain less lactose than regular dairy products.
Many people prefer dairy products without lactose. However, this does not help them much if they are allergic to the proteins
Milk allergy causes the immune system to overreact
If you have real milk allergy, your immune system overreacts (especially to milk protein). What happens, more specifically, is that white blood cells called Th2 lymphocytes initiate a production of antibodies that bind to the milk proteins, which activates several parts of the immune system, kind of like a chain reaction.
If you ingest dairy products, you may have allergic reactions in different parts of your body, simply because the immune system is unable to distinguish between dangerous proteins from microorganisms and proteins in the milk. This can lead to swollen mucosa, poor digestion, eczema, asthma, and a number of other symptoms.
Be careful with proteins if you have real milk allergy
Normal whole milk contains 3.5% protein. Cheese and skyr contain around 20% protein.
Components in cow’s milk may prevent the allergic reactions
The scientists from the University of Veterinary Medicine in Vienna have discovered that certain components in cow’s milk help prevent the allergic reactions caused by milk proteins. One of the worst milk allergens, a protein called beta-lactoglobulin, belongs to a particular group of proteins that are equipped with “pockets” that contain a vitamin A metabolite called retinoic acid or vitamin A acid.
If the pockets in these milk proteins are devoid of retinoic acid, the white Th2 blood cells are activated, causing an allergic chain reaction that produces undesirable antibodies.
The white blood cells may also react less aggressively without causing an allergic reaction, if the “pockets” in the beta-lactoglobulin milk proteins are filled with retinoic acid. In others words, if the cows’ feed contains a sufficient amount of vitamin A, it may have the potential to convert milk allergens into harmless proteins. This, however, requires that the cows eat a lot more grass and greens with a high vitamin A content. According to Karin Hufnagl, who headed the study, it remains uncertain if the same positive effect is obtainable with vitamin A supplementation. This warrants further studies.
The Austrian study is published in Scientific Reports 2018.
Milk was different in old days, and we got far fewer dairy products
In the old days, cows grazed on the pastures all summer, and their winter feed consisted mostly of straw and hey. Farmers eventually started feeding beets, corn, and soy to the cows so that they could be milked in the winter, as well. In 1882, the first dairy cooperative was established, and that was the beginning of the dairy industrialization. As time passed, concepts such as mandatory pasteurization and homogenization of milk were introduced.
Today, 84 percent of non-organic cows never graze. Since the 1850s, the milk yield has increased tenfold thanks to the changes in the feeding routines and breeding methods. Consequently, there is a huge difference between milk from corn-fed cows and milk from cows that have fed on grass and hay, which is a much more natural diet.
It is already an established fact that milk from corn-fed cows has a lower content of the beneficial omega-3 fatty acids. According to the above-mentioned Austrian study, it appears that the proteins in regular cow’s milk contain less retinoic acid, which protects against allergic reactions.
Although cow’s milk by nature is intended to help calves grow, more and more research suggests that organic milk is healthier for the simple reason that organic cattle as a minimum grazes from April 15. to November 1st.
Did you know that there is a huge difference between human breast milk and cow’s milk – and that cow’s milk contains far more proteins?
Dairy consumption has increased dramatically
Before the introduction of the dairy cooperatives, dairy consumption was rather limited. However, according to the statistics, dairy consumption in Denmark has increased, especially in the past decades. Although milk consumption has decreased slightly, the consumption of cheese and fermented dairy products has increased a lot. Just think of it, it is quite normal to use some sort of dairy product in first courses, main courses, and desserts.
Because of that, our intake of milk protein has increased dramatically, and that may contribute to the increasing rate of milk hypersensitivity.
In addition, there are many other proteins in milk, including casein and whey protein, which can trigger an immune response.
Did you know that milk hypersensitivity can also cause chronic inflammation because the immune system constantly reacts to the proteins?
Milk hypersensitivity is a controversial subject
According to official numbers, 3-5 percent of European children have regular milk hypersensitivity. Fewer adults are affected. This is only the case with classic allergy, which occurs immediately after consuming dairy products. Here, doctors can measure the presence of IgE antibodies with a skin prick test or a blood sample.
The immune system can also react with IgG antibodies and other substances, but where symptoms don’t show until later and may become more or less chronic. In Denmark, it is rather difficult to identify this type of allergy unless you consult a private clinic. The clinic then sends a blood sample to Germany where they can measure IgG antibodies. Because of this, many people suffer from milk hypersensitivity of some sort without ever getting a proper diagnosis. In fact, their doctors may even tell them that they are not allergic to milk, simply because there is no IgE reaction.
In the book “Mælk og Sundhed” (“Milk and Health”), biologist Ane Bodil Søgaard, chief physician Karen Østergaard, and scientist Troels Østergaard have combed through the scientific studies (that are not sponsored by the dairy industry) to see if there is a link between the large intake of dairy products and the increasing rate of allergies and other types of hypersensitivity. Many people are in a grey zone and have not been given the correct diagnosis or do not receive the right type of medical treatment.
On page 85, you can find the following overview of health problems that can be relieved by avoiding dairy products:
- Poor digestion with acid reflux, bad breath, and coated tongue
- Stomach pain
- Stool problems, diarrhea, constipation (or both)
- Increased vaginal discharge (that is not related to any other disease)
- Cysts in the breasts and ovaries
- Pain in the breasts
- Certain types of eczema
- Inflamed bumps (pustules)
- Scaly, red spots – especially in the face
- A tendency to sweat a lot
- Problems that are caused by regular allergy
- Problems falling asleep because of cold or warm feet
Ear, nose, and throat
- Colds in children
- Middle ear infection (otitis)
- Chronic sinus infections
- Mood problems (irritability, fear, tendency to become depressed)
Karin Hufnagl et al. Retinoic acid prevents immunogenicity of milk lipocalin Bos d 5 through binding to its immune-dominant T-cell epitope. Scientific Reports. 2018
University of Veterinary Medicine – Vienna. Vitamin A in cattle fodder is potentially protecting against cow´s milk allergy. ScienceDaily. 2018
Ane Bodil Søgaard, Karen Østergaard og Troels Østergaard. Mælk og sundhed. Books on Demand
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