Food allergies are a growing public health concern. Allergy sufferers (e.g. pollen, birch, grass) often develop reactions to apparently unrelated foods. This phenomenon is known as cross-food reactivity. Cross-reactivity occurs when the immune system recognizes similar proteins in different substances (e.g., pollen and food) for structural similarity and triggers an allergic reaction. In the case of food allergies, the immune system has a reactivity towards dietary proteins that are recognised as foreign when they reach the intestine or cross the intestinal barrier. Food allergy can therefore be seen as an error of our immune system that recognizes as a foreign agent (antigen) foods or ingredients that are actually harmless.
The allergic reaction causes different symptomatologies that depend on the degree of sensitization that varies from subject to subject.
Therefore, the severity of symptoms is very varied. Mild reactions may be observed such as allergic oral syndrome, with itching, swelling or tingling of the lips, tongue, palate immediately after eating food; hives and angioedema, with appearance of pruriginous skin rash or swelling of the face and lips; Gastrointestinal symptoms with nausea, vomiting, abdominal pain, diarrhea; severe systemic reactions with anaphylaxis are rarely observed.
Grasses are primarily known to cause seasonal allergic rhinitis, commonly called "hay fever". The pollen of these widely distributed plants releases allergens that cause sneezing, itching in the nose and eyes, and congestion. However, the proteins present in the pollen of graminaceous plants may be similar to those found in some foods of plant origin.
People who are allergic to grass pollen may have allergic reactions to various foods, including:
- Cereals: wheat, barley, rye, oats, maize.
- Fruits: Peaches, apricots, cherries, kiwi, watermelon, melon, orange, plum.
- Dried fruit: Peanuts, almonds.
- Vegetables: tomatoes, potatoes, peppers.
- Legumes: Peas.
The diagnosis of cross-food reactivity is based on the patient’s history, allergy tests (skin and/or blood) and, in some cases, oral provocation test.
The main management is to avoid foods that trigger the reaction. However, tolerance can vary from person to person. In some cases cooking reduces allergenicity, in other cases the allergen is only present in the peel of the fruit. The best way to treat cross allergies is to avoid contact with the agent that triggers them, food should be avoided especially in the critical period of flowering of the grasses. In any case, if cross-food reactivity is suspected, it is crucial to consult a specialist physician for an accurate assessment.
Some gemmotherapists have proven useful in modulating the immune system response and reducing allergic reactivity. They act gently but deeply, helping the body to prepare and react less intensively to contact with allergens. These include:
- Black currant (Ribes nigrum): acts as an anti-inflammatory and antihistamine, helping to prevent and relieve allergic symptoms at the respiratory and skin levels.
- Hornbeam (Carpinus betulus): Useful especially in case of respiratory allergies with nasal congestion and sinusitis, thanks to its decongestant and soothing action on the mucous membranes.
- Beech (Fagus sylvatica): acts as an antihistamine and helps modulate the immune response, which is useful in different forms of allergy.
- Rosehip (Rosa canina): supports the immune system and has an anti-inflammatory action, useful in case of allergies, especially in children.
Gemmotherapy can be a valuable support for the prevention of allergies, but it does not replace any ongoing medical therapies.
(Article by nutritional biologist Maddalena Della Bianca)
