MOSCOW, November 16, Vladislav Strekopytov. Even hidden allergic reactions to the most common foods, such as dairy products, can provoke serious cardiovascular diseases. American scientists came to this conclusion after analyzing data from several thousand patients, and not only allergy sufferers.
Food allergies occur when the immune system mistakenly perceives certain proteins in foods as dangerous. Or because immunoglobulin E (IgE), an important element of this system, binds to food molecules and forms inflammatory substances, in particular histamine.
Cow's milk, peanuts, eggs, shellfish, crustaceans, fish, tree nuts, soy, wheat, sesame, rice, and fruits are considered especially allergenic. Every tenth person in the world is allergic to certain foods, and in the last two to three years, WHO has noted a deterioration in statistics, especially in developed countries. Children suffer the most, but adults have plenty of problems too.
The main symptom is a rash on the skin, which is not always noticeable. However, if you do not attach importance to them, complications are possible. Allergies can cause serious illness.
What's on the skin is just the tip of the iceberg. Allergies primarily affect the internal organs. Autoimmune inflammatory processes affect the lungs, gastrointestinal tract, and kidneys. And recently, American scientists showed that sensitivity to common food allergens, such as dairy products and peanuts, may be an important and previously underestimated cause of cardiovascular disease (CVD).
Allergies and the Heart
Americans analyzed the database of two Department of Health projects – the National Health and Nutrition Examination Survey (NHANES) and the Multi-Ethnic Study of Atherosclerosis (MESA). There is information about hundreds of thousands of people, their lifestyle, nutritional habits, diagnoses.
Based on the level of IgE in the analyses, several groups were identified: without signs of allergy and those who had increased general immunoglobulin E and specific immunoglobulin E to cow's milk, peanuts and some other products. For each, we built proportional risk models for the development of cardiovascular diseases and death from them over the years, adjusted for gender, age, ethnicity, education, as well as taking into account the factors of smoking and previously diagnosed CVD, hypertension, diabetes and asthma. In total, the sample included 5374 people, 285 of whom died during the observation period (15 years for NHANES and 19 for MESA) due to heart and vascular diseases.
It turns out that those who develop antibodies to cow's milk and, to a lesser extent, peanuts and shrimp, are especially susceptible to cardiovascular disease. This factor is comparable or even superior to traditional CVD risks such as smoking, diabetes and rheumatoid arthritis.
“A possible mechanism is the activation of the “allergic” inflammatory cascade,” explains Yulia Mironova, a therapist at the BestDoctor group of companies. “IgE antibodies to food induce special mast cells to release chemicals – cytokines. Their excess damages the internal walls of blood vessels, and atherosclerotic plaques form there faster – the main cause of heart attacks and strokes.”
The Hidden Threat
According to statistics, approximately 15 percent of adults have IgE antibodies to cow's milk and peanuts in their blood. But, as a rule, there are no allergies, and people, unsuspectingly, continue to regularly consume foods that cause a hidden inflammatory reaction in them.
“And this can lead to heart problems over time” ,” Jeffrey Wilson, MD, an allergy and immunology expert at the University of Virginia School of Medicine, was quoted as saying in a press release.
“The American study is notable for being the first to identify a link between cardiovascular disease and increased levels of IgE antibodies to common foods in people without obvious symptoms of food allergy,” Mironova notes. “It is possible that allergic reactions are recognized as a risk factor for cardiovascular disease, but it is necessary understand what is the cause and what is the effect.”
It really isn't clear yet. CVD is quite capable of increasing sensitivity to allergens. Genetics and the environment can also play a role.
Find the molecule
An allergy to milk should not be confused with intolerance to lactose, milk sugar. The symptoms are similar – vomiting, diarrhea, pain and bloating – but the processes are fundamentally different.
People with intolerance lack or produce insufficient amounts of the lactase enzyme. It breaks down lactose into glucose and galactose, which are absorbed by the small intestine. If it is not there, lactose remains in the intestines and binds with water – hence diarrhea. In addition, intestinal bacteria cause fermentation of milk sugar, which results in bloating.
In the acute phase, allergies are accompanied by redness, itching, and digestive problems. In chronic cases, tissues and the gastrointestinal tract are damaged. Abnormalities in the heart and blood vessels have not yet been known.
So far, the connection with CVD is considered to be only one type of allergy – the so-called alpha-gal syndrome (named after the carbohydrate galactose-alpha-1,3-galactose contained in cell membranes), a specific allergic IgE reaction to red meat. The peculiarity is that it appears only after the bite of certain types of ticks, whose saliva interacts with alpha-galactose. This leads to the formation of atherosclerotic plaques in the vessels.
“In principle, any acute allergic reaction in a complicated form can cause deterioration in the heart and blood vessels, increased blood pressure, dizziness and loss of consciousness,” says allergist-immunologist of the European Medical Center (EMC), first category doctor Alla Rafaelyan. “It is important to understand that that increased total or specific IgE is not a necessary prerequisite for food allergy. Activation of the immune response is necessary.”
In the case of alpha-gal, this is a tick bite. And the situation with cardiovascular disorders in reactions to milk has yet to be clarified.
“The molecular levels, genotypes and phenotypes of various people are now being studied. Perhaps for some they will find a connection between antibodies to allergens in the blood and complications of the cardiovascular system, – notes doctor allergist-immunologist of the Federal State Budgetary Institution “United Hospital with Clinic” of the Presidential Administration, Candidate of Medical Sciences Victoria Merkulova. – Science functions like this: accumulation of data, then generalizations, identification of cause-and-effect relationships and conclusions that serve as the basis for clinical recommendations.”< br />In the meantime, experts advise that at the slightest suspicion of an allergy, contact a specialist and undergo a comprehensive examination, including a molecular examination that determines the main allergens.