Development of Food Allergies: Role of Age and Environment

What is considered pathological in adulthood (poor functionality of the enzymatic systems and reduced immune response) is extremely common in the neonatal period. In fact, when he is born, the baby’s immune system is still incomplete.

Weaning too early can therefore lead to the onset of food allergies, firstly because the enzymatic functionality is not complete (some proteins are not perfectly digested) and secondly because the intestinal mucosa is not yet fully efficient (it can allow food antigens to pass through ); the same goes for the immune system. It is therefore no coincidence that the majority of allergies occur in the first period of life (in childhood the most common food allergy develops towards cow’s milk ). Fortunately, within 3 years, there is a regression in 44-87% of cases, resulting in desensitization of the organism. Conversely, the later the allergy appears, the lower the probability of its spontaneous regression.

Environmental factors

What environmental factors affect food allergies?

The incidence of food allergies is constantly growing, especially in industrialized countries. The blame is often placed on various environmental factors even if not all of them have been proven to be actually involved

Environmental factors NOT involved

Contrary to what was initially hypothesized, environmental factors are NOT involved in the mechanism of food allergies:

• Smog
• Stress
• Reduced physical exercise
• Smoking.

Scientific studies have confirmed that these factors have no role in the development of allergic pathologies and, even if they can increase the synthesis of endogenous histamine and make the symptoms more evident, they cannot be considered the cause of the increased incidence of allergic pathologies.

Environmental factors actually involved

• Too much hygiene and small families: The main factors implicated in this worrying phenomenon should instead be found in excessive hygiene and reduced family size. In fact, it has been observed that children from small families are more likely to develop allergies than those who live in extended families.
• GDP: Another interesting aspect is that the percentage of allergies in industrialized countries is proportional to the GDP: the richer the country, the higher the percentage of allergic inhabitants. The same relationship also applies within a single family unit , where the incidence of allergies is directly proportional to the socio-economic level.
• Vaccines: if the use of vaccines, disinfectants and antibiotics protects us from numerous diseases, on the other hand, when they are used obsessively, they remove stimuli from the immune system which, by not coming into contact with its natural enemies, so as not to get too bored diverts his attention towards food allergens. Pharmacological studies have shown that in normal conditions T lymphocytes produce gamma interferon , which in turn stimulates the production of antibacterial and antiviral antibodies ornatural killer cells . In environments where excessive hygiene predominates, there is instead a greater production of immunoglobulin E , i.e. those antibodies directly responsible for food allergies.

The explanation should therefore be sought above all in the excessive level of hygiene compared to the past, understood as reduced exposure to antigens .

What factors can interfere with food allergy symptoms?

There are also other factors, food and non-food, which can interfere with the severity of the symptoms associated with allergic manifestations.

Cold and histamine

Some food allergies become more serious in the winter because the cold stimulates the production of histamine which, added to that released during allergic reactions , causes more evident symptoms.

Number of allergens

In the presence of allergy to multiple antigens, the allergic manifestation becomes more intense when multiple allergens are present at the same time.

In a recent study it was observed that the incidence of atopic diseases and autoimmune diseases in rich countries is proportional to the GDP (Gross Domestic Product) and within these countries it is proportional to the socio-economic level of the family.
The increase in allergies could be attributed to a reduced chronic exposure to infectious agents in the first years of life, this:

• thanks to the use of antibiotics
• thanks to vaccines
• for the best hygienic conditions
• because foodsare less contaminated by microorganisms
• because the water we drink is practically sterile

When the immune system does not encounter “natural enemies” it diverts its attention towards other exogenous molecules. Under normal conditions, T lymphocytes produce interferon-gamma which stimulates the production of antibacterial and antiviral antibodies and killer cells. In environments where excessive hygiene predominates, the immune system produces interleukin (IL4) which in turn induces the production of IgE antibodies .