According to recent estimates, almost half a million Americans are already living with this unpleasant disease.
Photo: Maria LENZ
An unusual epidemic has gripped the United States; the number of people allergic to meat is growing in the country. According to the latest estimates, with this unpleasant disease Almost half a million Americans already live. Moreover, intolerance to meat and dairy products is caused after the bite of a certain species of tick with the romantic name Amblyomma americanum or the “Lone Star” tick, so named probably because the white spot on the back of the tick is somewhat reminiscent of the Texas state flag.
How did such an unusual type of allergy appear when people who have been eating beef at barbecues for years suddenly can’t stand meat anymore? Nikolai Kryuchkov, candidate of medical sciences, immunologist, general director of a contract research company, told Komsomolskaya Pravda why this meat intolerance syndrome can be life-threatening in some cases and whether forced refusal of red meat and milk threatens Russians.
In recent years, 15–17 thousand new cases of allergies to red meat and dairy products have been registered in the United States, but the problem itself came to the attention of doctors quite recently, in the early 2000s.
– At first, we simply began to notice similar cases, people developing intolerance to dairy and meat products (red meat, beef, pork, lamb). Then they began to study this phenomenon and after a couple of years it was possible to compare it with a certain event – a tick bite. Finally, scientists have discovered the main component of the saliva of some ticks, which is responsible for the development of an allergy to alpha-Gal, says Nikolai Kryuchkov. – In America, one species of tick, Amblyomma americanum, is dangerous in this regard, but there are other ticks of the ixodid family, whose bites can also cause a similar allergy.
WHAT IS THIS ALPHA-GAL AND HOW DOES A MEAT ALLERGY DEVELOP?
Alpha-Gal is contained in the glycoproteins of tick saliva along with a huge number of biologically active substances, including those that cause serious infections, which ticks are so rich in.
Alpha-Gal is a disaccharide that is not produced in the human body, so its molecule is perceived as foreign by the immune system.
– Normally, the immune system synthesizes IgM antibodies, which help control the development of infections. But when a tick bite occurs, their saliva contains a whole “cocktail” of biologically active substances, which, when entering the human body, shifts the immune response in at least two ways towards a specific Th2 immune response, says Nikolai Kryuchkov.
What does this mean in practice? This type of immune response is also called “allergic” because it is accompanied by multiple allergic reactions. The immune system begins to synthesize IgE class antibodies, which, with a certain cellular interaction, begin to release histamine into the environment, which causes an allergic reaction. Moreover, mature immune cells also switch to the synthesis of IgE antibodies.
– Alpha-Gal is found not only in tick saliva, but also in red meat, milk, and animal products such as gelatin, for example. Therefore, as soon as the immune response is switched after a tick bite, and a person eats some red meat, which contains alpha-gal, the immune reaction turns on. Moreover, this reaction is delayed and its deployment takes from 2 to 6 hours, says our expert.
WHAT ARE THE SYMPTOMS OF A MEAT ALLERGY?
Frequent manifestations of meat allergies are:
– symptoms similar to “indigestion”: pain and heaviness in the abdomen, nausea, vomiting;
– rash: very itchy on different parts of the body. It appears suddenly, lasts for a while and goes away.
In this case, the person does not even think that he has some kind of allergy to alpha-Gal, since its manifestations are so blurred and not acute. Rather, in this case, people do not go to the doctor and begin to choose diets from foods that do not cause discomfort; they think that they are experiencing gastritis or heartburn.
Where can meat allergies be common in Russia?
You should be attentive to such symptoms, first of all, in Siberia and beyond the Urals – these are regions of our country rich in various ticks. However, such a nuisance as a tick bite from the ixodid genus can also happen in the European part of Russia, especially during the period of tick activity. If in our country registered With about 4 thousand cases of tick-borne borreliosis or Lyme disease per year, it is clear that the overall number of bites reported is higher. Plus – there are even more unregistered bites that people simply don’t pay attention to.
“It is worth noting that not every tick bite will cause the development of alpha-Gal allergy,” says Nikolai Kryuchkov. – Several factors must come together – this is the danger of the tick itself and how rich its “salivary cocktail” is in glycoproteins with alpha-Gal. Plus, the state of the immune system of the person who received the bite and certain genetic factors also influence.
When can a meat allergy be life-threatening?
There are examples from the early 2000s when people with similar allergies were given a drug – monoclonal antibodies to treat cancer – and a small number of people developed severe anaphylactic reactions. At that time, the connection with tick bites was not yet suspected, but through further observation it was possible to link this severe allergic reaction to the drug with alpha-Gal and the tick bite.
HOW TO PROTECT YOURSELF?
– If you suspect that you are intolerant to meat and dairy products (see symptoms above), you can get tested, for example, a quantitative test that measures the level of IgE antibodies to alpha-Gal (anti-alpha-Gal IgE).
– Pass a skin test for allergens, including meat allergen.
– If alpha-Gal syndrome is confirmed, then its negative manifestations can be prevented by following a restrictive diet and excluding meat (beef, lamb, pork) and dairy products from the diet.
– It is important to protect yourself from ticks. Alpha-Gal syndrome is another reason not to communicate with these small creatures that carry several dangerous infections at once, such as tick-borne borreliosis and tick-borne encephalitis, for example.
Why is it important to know your allergic reactions?
As life progresses, the degree of an allergic reaction may change, increase or, on the contrary, decrease. The range of allergens – in this case, meat products – can also change over time, which means tracking your sensitivity can prevent accidental anaphylactic shock.