Blocked nose, itchy or runny nose, red eyes, the arrival of spring does not please everyone. Indeed, it is also the season of respiratory allergies which, although often benign, are nonetheless very unpleasant.
What is seasonal allergy?
Allergy can be explained as an excessive response of the immune system to a substance that it recognises as foreign and which is then called an allergen.
When the immune system is functioning properly, the body is not disturbed in any way. However, after exposure to a particular substance, the body may become overly defensive. While this allergenic substance will be perfectly harmless for some people, in sensitized people it will be considered dangerous.
The mechanism of action of the allergy takes place in two stages:
- First a sensitisation phase during which the immune system identifies the foreign substance as dangerous (1st contact). It starts to produce antibodies against this allergen.
- The allergic reaction is triggered. The immune system reacts; the antibodies seek to eliminate the allergen by triggering a series of defence reactions. They then bind to other cells of the immune system: mast cells, which release histamine. This is how the first symptoms appear.
If the allergy occurs only during certain seasons, it is called a seasonal allergy. The most common is pollen allergy.
The sensitized person’s body reacts in an extreme way to pollen produced by certain plants (trees, grasses or herbs) and dispersed by the wind. This is most often referred to as “seasonal allergic rhinitis” (or “allergic rhino-conjunctivitis”).
Allergic reactions are caused by six major families of trees:
- Betulaceae: birch, alder, hornbeam, hazelnut…
- cupressaceae: cypress, juniper, thuja
- the fagaceae: beech, chestnut, oak
- oleaceae: olive tree, ash tree, privet
- Pinaceae: fir, pine, spruce, larch, cedar
- Plananaceae: plane tree
The causes of seasonal allergies are still poorly explained, but because they are constantly on the increase, they are particularly incriminating to our current lifestyles:
- Pollution. Diesel particles are dangerous because certain chemical compounds and allergenic pollens cling to them, which increases the risk of allergy. Ozone pollution is also a factor in allergies because it weakens the nasal mucous membrane, which absorbs 40% of inhaled ozone.
- Living in poorly ventilated and overheated homes
- tobacco that weakens the mucous membranes
- stress, which acts as a pollutant for the body and mind. Several studies show that stress, because of its adverse effect on the body’s immune system and on the body’s protective systems against inflammation, is associated with an increased risk of allergic rhinitis and asthma.
- global warming. The “mild” periods of the year now begin earlier and end later, and as plants grow faster, the length of pollen seasons and the amount of pollen in the environment increases.
- Globalization. Importing plants into countries where they do not grow naturally exposes them to new allergens that trigger or promote new allergies.
What are the symptoms of seasonal allergy?
When pollen is present in the air, it can be deposited on the skin, eyes, nose and bronchial tubes, causing symptoms such as :
- a stinging, runny or stuffy nose,
- red, watery eyes,
- tension in the sinuses,
- a sore throat,
- a cough,
- difficulty breathing,
- an alteration of taste
But in about 15% of allergy sufferers, these symptoms are accompanied by medical complications: chronic sinusitis and sinusitis, ear infections, sleep apnea, reduced quality of sleep, difficulty concentrating and even asthma.
Unlike bacterial or viral infections, seasonal allergies do not cause fever, aches or headaches, nasal and pharyngeal discharge remains clear and there is no purulent sputum.
When the symptoms of allergic rhinitis are particularly intense, it is recommended to consult an allergist or ENT specialist, who will confirm the diagnosis by skin and/or blood tests and possibly carry out desensitisation.
Seasonal anti-allergy food
Surprisingly – since it is not a food allergy, adapted menus can prevent seasonal allergies and limit their symptoms. An anti-inflammatory diet rich in antioxidants is particularly suitable.
Make the most of :
- fruits and vegetables rich in vitamin C. This vitamin has a natural anti-histaminic action by blocking the secretion of histamine by white blood cells. Think of guava, yellow pepper, blackcurrant, kiwi, lychee, papaya and citrus fruits.
- Cruciferous plants (cabbage, broccoli, red cabbage, kale, rutabaga, turnip…) This family of plants helps clear the airways of mucus that clogs them.
- blackcurrant and black grape rich in a polyphenol called resveratrol which tends to suppress allergic reactions to IgE (immunoglobulin E stimulated antibodies).
- garlic and onion, rich in quercetin which also acts as a natural antihistamine. Apples also contain quercetin, but should be avoided if you are allergic to birch due to cross-allergy.
- foods containing omega-3s with anti-inflammatory properties: fatty fish (tuna, salmon, herring, sardines, trout…beware however of canned food which is often rich in histamine), rapeseed, flax, hemp and oleaginous oils (walnuts, hazelnuts, almonds…).
- ginger and turmeric, which also tend to limit inflammation.
On the other hand, certain foods should be limited, if not excluded, at least for the duration of the allergy:
- coffee, which increases histamine production and increases the feeling of general inflammation. In addition, it weakens the intestinal mucous membrane, which contributes to the phenomenon of hyper permeability which reduces immunity.
- spicy food
- dairy products. Cheese and dairy products tend to increase mucus production and inflammation.
- refined sugar, which causes large fluctuations in blood sugar levels that trigger adrenaline rushes responsible for histamine release.
- alcohol which causes dilation of blood vessels and aggravates irritation of the nasal mucosa and the sensation of a blocked nose.
It is also advisable to avoid, as far as possible, medicines that weaken the intestinal mucosa and promote intestinal hyper-permeability:
Food supplements for seasonal allergies
Traditionally, antihistamines and decongestants have been prescribed to relieve the symptoms of respiratory allergies. These are often effective, but have side effects. The former can lead to so-called “anticholinergic” effects (drowsiness, dry mouth, blurred vision, constipation, difficulty urinating, confusion or dizziness). The latter can, in the long term, aggravate or prolong nasal congestion (this is called the rebound effect) and ultimately lead to chronic congestion.
It may therefore be interesting if you are prone to these side effects or if the symptoms are resistant to treatment to use dietary supplements.
- Probiotics, especially lactobacillus strains, are effective in the prevention of allergic rhinitis. Indeed, by restoring the intestinal flora, they strengthen immunity and thus play a positive role against allergies. In addition, certain strains are also believed to reduce the symptoms of rhinitis and conjunctivitis.
- Quercetin is a flavonoid from a plant source that inhibits histamine production. It is now thought that quercetin may alleviate the inflammatory reactions of allergic rhinitis.
- Vitamin D has important properties in modulating the immune response. It is noted that vitamin deficiency frequently induces allergy phenomena.
- Nettle, rich in minerals, vitamins and trace elements, has a restorative and stimulating action, and allows to fill up with tonus and vitality.
- Blackcurrant which, being an excellent anti-inflammatory, acts effectively during allergic episodes and significantly reduces the symptoms. It also reduces the fatigue often associated with seasonal rhino-conjunctivitis.