Preventing and relieving asthma through diet

Asthma is a chronic inflammatory syndrome of the bronchial mucosa. It is estimated that one in 20 people worldwide are affected by asthma. The WHO is concerned about the increase in children affected by asthma. In fact, the prevalence of asthma has tripled over the last 20 years: 2% in the 90s compared to 6% today (the change is however less marked in adults). Asthma is currently the 28th leading cause of reduced life expectancy worldwide. Several hypotheses are put forward to explain this sharp increase: environmental changes, confinement of living spaces, pollution, allergic terrain, urbanization, modification of eating behaviors, etc.

Asthma is characterized by several changes in the functioning of the airways: inflammation of the epithelium of the bronchi, contraction of smooth muscles (bronchoconstriction) and hypersecretion of mucus. The whole reduces the diameter of the bronchi making breathing difficult. Permanent inflammation of the bronchi makes them extremely sensitive to external interactions. There abnormal reaction of the immune system facing certain substances causes an asthma attack. The symptoms of an asthma attack are multiple: wheezing, difficulty breathing, coughing, shortness of breath, etc. They are present intermittently and seem to get worse at night. The triggering factors for an attack are specific to each person: dust, viral infection, smoke, strong emotions, grass and tree pollen, hair, strong odors, cold, feathers, certain medications, etc.

For now, there is no cure for asthma. Existing treatments are palliative in nature: they aim to improve the comfort of life of an asthmatic. Therefore, it is important not to neglect other areas of non-therapeutic intervention, such as diet.

The primary objective of nutrition is toimprove symptoms of asthma attacks with emphasis on:

• Antioxidants: oxidative stress plays an important role in inflammatory pathologies, such as asthma. Oxidative stress is an imbalance between the oxidant/antioxidant balance in favor of an excess of free radicals in the body. These excess free radicals leadsnt dysfunction of cells and accelerates their death. Antioxidant nutrients neutralize free radicals or contribute to the functioning of antioxidant enzymes. We find vitamins (E, C and B2), trace elements (copper, iron, manganese, selenium and zinc), phytonutrients (carotenoids, polyphenols, terpenes, isocyanates, phytic acid, etc.) and cysteine. . A diet rich in antioxidants strengthens antioxidant protection of the lungs and improves the symptoms of asthma attacks.

• Vitamin D : it seems that vitamin D limits the exacerbation of asthma symptoms. A meta-analysis observes a positive relationship between vitamin D supplementation and asthma symptoms.

• Probiotics: probiotics are live microorganisms which, when ingested in sufficient quantities, exert positive effects on health by modulating the composition of the intestinal flora. Probiotics may improve asthma symptoms. This benefit seems to be more effective in children.

Chronic and exacerbated inflammation of the bronchi causes their hypersensitivity to certain substances. Therefore, it is essential to limit inflammation by focusing on:

• Omega 3 : alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are anti-inflammatory polyunsaturated fatty acids. The latter form substances (resolvin, maresin, protectin, etc.) which modulate the intensity and duration of the inflammatory process. They are also called inflammatory pro-resolvers. More precisely, they inhibit the production of molecules and mediators of inflammation and limit chemotaxis (migration of immune cells to the inflammatory site). Our diet is deficient in omega-3. To reduce chronic inflammation of the bronchi, it is obvious to increase dietary intake of omega-3. 

Conversely, it is necessary to limit nutrients that amplify inflammation and therefore the symptoms of asthma attacks, such as:

• Omega-6 : linoleic acid (LA) and arachidonic acid (AA) are pro-inflammatory polyunsaturated fatty acids. Omega-6 are precursors of the inflammatory mediators: prostaglandin and leukotriene. The latter play several roles in the inflammatory process (chemotaxis, increases vascular permeability, pain, etc.). Leukotrienes also have the particularity of stimulating the contraction of smooth muscles of blood vessels (vasoconstriction) and bronchi (bronchoconstriction). Bronchoconstriction is a symptom of an asthma attack.

• Saturated fatty acids : in excess, saturated fatty acids (SFA) promote excessive inflammatory reactions. Chronic inflammation of the bronchi increases sensitivity to substances that trigger asthma attacks.

• The alcohol : alcoholic beverages are pro-inflammatory: they increase biological markers of inflammation (interleukin-6, CRP, fibrinogen).

• Nitrites: nitrites are anions naturally present in nature. They are used in the form of nitrite salt in the food industry. In abundance, proteins and nitrites interact and give rise to N-nitroso compounds. An increase in reactive nitrosating species increases nitrosating stress, which would aggravate oxidative stress and amplify the concentration of biological markers of inflammation. All this would worsen the symptoms of asthma attacks.

Prebiotics would also have an interesting property in the prevention of asthma. Inulin, olifofructose, fructo-oligosaccharides (FOS), xylo-oligosaccharides (XOS) and galacto-oligosaccharides (GOS) are prebiotic fiber. They feed a selective group of microorganisms living in the intestine. Thus, they stimulate the development of bacteria positive for health at the expense of harmful bacteria. The intestinal flora is closely related to the immune system. The degradation products of prebiotics by the intestinal flora: short-chain fatty acids (SCFA), would reduce the risk of asthma attacks.

PARTICULAR CASE : sometimes asthma is a symptom of food allergy. In this case, it is important to exclude the allergen from your diet.

A case control study analyzed the impact of fast food on children's health. The latter notes that a diet rich in fast food (more than three times a week) significantly increases the prevalence of asthma symptoms in children. Several hypotheses can explain the harmful effects of fast food on asthma: excess saturated fatty acids, imbalance in the omega-3/omega-6 ratio, deficit of antioxidants, disruption of the ecology of the intestinal microbiota, etc. . 

We recommend you to favor homemade.

Two arguments justify the avoidance of cold meats in cases of asthma. First of all, they are vectors of “bad fats”: saturated fatty acids, on average 6 g of SFA in 100 g, and omega-6, with around 2 g per 100 g. Finally, nitrite salt is an additive traditionally used in cold meats.

We recommend you :

• to consume a maximum of 50 g of cold meats per week: sausages, dumplings, pâté, salami, bacon, etc.

• to favor nitrite-free cold meats.

Animal fats are rich in saturated fatty acids. In excess, saturated fats are pro-inflammatory.

We recommend you :

• consume a maximum of 20 g of butter per day. 20 g of butter provides 11 g of saturated fatty acids.

• consume a maximum of 60 g of crème fraîche per day. 60 g of crème fraîche contains 12 g of saturated fatty acids.

• avoid animal fats: lard, tallow, poultry fat, etc.

Some vegetable fats are mainly composed of saturated fatty acids. In excess, they can increase inflammation, including that of the bronchi. However, further arguments are needed to confirm this fact. As a precaution, please avoid excess.

Tip: to recognize vegetable oils rich in SFA, simply observe them at room temperature. If the oil is solid, it is mainly composed of AGS. If the oil is fluid, it contains no or very little AGS.

We recommend you : 

• consume a maximum of one tablespoon of vegetable oils rich in saturated fatty acids per day. Lvegetable oils rich in SFA are thecoconut oil (or copra), palm oil (or palm kernel), shea Butter, THE cocoa butter, etc.

• consume a maximum of 20 g of margarine per day. Generally speaking, margarines are composed of vegetable oils rich in SFA (coconut or palm) or omega-6 (sunflower).

Omega-6 metabolism products contribute to the inflammatory process and promote contraction of bronchial smooth muscles. The standard diet in Western countries is too rich in omega-6. Reviewing your consumption of foods rich in omega-6 is fundamental to reducing chronic inflammation of the bronchi.

We recommend you :

• to limit vegetable oils rich in omega-6: grapeseed oil, sunflower oil, corn oil, cottonseed oil, sesame oil, safflower oil, peanut oil.

• to limit seeds rich in omega-6: sesame seeds, pumpkin seeds.

• to limit nuts rich in omega-6: pine nuts, brazil nut, pecans, pistachio, peanuts (including peanut butter).

• to favor vegetable oils, seeds and nuts rich in omega-3 (indicated below), in order to rebalance the omega-3/omega-6 ratio.

Alcohol consumption amplifies inflammatory processes. Abnormal inflammation of the bronchi increases the reactivity of the airways (asthma attack).

We recommend you to limit the consumption of alcoholic beverages: maximum one standard drink per day, and not every day.

A diet rich in fruits, vegetables and legumes improves the health of asthmatics, thanks to their constituents:

• antioxidants: we find a wide range of antioxidants in plants, such as vitamin C and phytonutrients.

• prebiotics: These are specific fibers found in fruits, vegetables and pulses. They are found mainly in plants of the Asteraceae family (chicory roots, artichoke, salsify, dandelion), of the Liliaceae family (asparagus, onion, shallot, garlic), in Jerusalem artichokes and in legumes (lentils, chickpeas, red beans, etc.).

• probiotics : eaten fermented, vegetables are sources of probiotics. Probiotics maintain the diversity of the intestinal microbiota.

We recommend you :

• to eat at least three fruits and vegetables per day. The plants richest in antioxidants are: red fruits (blackcurrants, blueberries, blackberries, cranberries, physalis, etc.), cabbage, citrus fruits, broccoli, peppers or even lettuces (arugula, salad, batavia, etc.), etc. .

• favor raw fruits and vegetables to preserve heat-sensitive antioxidants.

• to consume fermented vegetables regularly: at least once every two weeks.

• to consume vegetables rich in prebiotics, to potentiate the action of probiotics.

• to eat at least two different dried vegetables per week.

Several constituents of fatty fish help limit inflammation and the severity of asthma attacks. All the antioxidant trace elements are present: copper, iron, manganese, selenium and zinc. These contribute to the functioning of the body's defense system against oxidative stress. We also find vitamin E, the most powerful antioxidant vitamin.

In addition, fatty fish provide all the omega-3s: ALA, EPA and DHA. These will help rebalance the omega-3/omega-6 ratio and limit the runaway inflammation.

Without forgetting the famous vitamin D, also available in fatty fish. For a portion (100 g) of fatty fish consumed, there is an average of 10 µg of vitamin D, or more than 65% of the RNP (nutritional recommendation for the population).

We recommend you :

• to consume at least one fatty fish per week: salmon, sardines, mackerel, herring, trout, eel, etc.

• to favor small fatty fish, lower in pollutants: sardines and mackerel.

THE walnut kernels are particularly interesting for their contribution in omega-3. There are approximately 1.1 g of alpha-linolenic acid (ALA) in 15 g of walnut kernels. In addition, there are good amounts of antioxidants found in this nut: manganese, copper, selenium, zinc and vitamin E.

Like walnut kernels, linseed and the chia seeds are full of ALA. There is an average of 1.6 g of ALA in 15 g of flax seeds, and 2.6 g of ALA in 15 g of chia seeds. Alongside omega-3, seeds also accumulate antioxidants: zinc, manganese and copper. It is preferable to consume ground seeds (especially flax seeds) in order to make their micronutrients accessible.

Finally, certain vegetable oils are concentrates of omega-3 that should not be neglected.

We recommend you :

• consume 15 g of walnut kernels or ground seeds per day.  

• enrich your meals with vegetable oils rich in omega-3, such aslinseed oil, l’soya oil, rapeseed oil,camelina oil, l'perilla oil, l'chia oil, etc.

• to consume raw vegetable oils, as a seasoning, because omega-3s are sensitive to heat.

The Bleu-Blanc-Cœur label certifies that the animals' feed is rich in omega-3 in particular and respects a good omega 6/omega 3 ratio (feed based on soya, flax or rapeseed meal). Certified foods therefore provide more omega-3 than those not recognized by the label.

We recommend you to favor “Bleu-Blanc-Cœur” certified foods when purchasing. This concerns a wide range of products: meats, dairy products, eggs, cold meats, oils, fish, bread, etc. 

A food allergy corresponds to a inappropriate reaction of the immune system facing a food substance. It identifies the allergen as the aggressor. After sensitization, the inflammatory reaction is organized, which translates clinically into: sneezing, a dry cough, a scratchy throat, a skin rash... or an asthma attack.

The main food allergens are dairy products, eggs, seafood, nuts, soy, etc.

In addition, other foods can also cause false allergies. These are rich in histamine. Histamine is a pro-inflammatory mediator: it is a powerful vasodilator, it increases vascular permeability and stimulates the nerves responsible for pain. Note that a deficiency in diamine oxidase (enzyme responsible for the breakdown of histamine) promotes sensitivity to histamine, we then speak of histamine intolerance.

The foods richest in histamine are: fermented foods (cheese, fermented vegetables, etc.), cold meats, alcohol (especially beer), chocolate, fish flesh, smoked meats, smoked fish , tomatoes (and their derivatives), spinach, eggplant, avocados, ripe bananas, kiwis, pineapples, etc.

If your asthma attack is identified as a result of a food allergy, please consult an allergist and exclude the trigger food(s) from your diet.

• Practice appropriate physical activity: sport is essential to fight against asthma. Physical activity develops lung capacity and strengthens respiratory muscles. However, sport can be the cause of an asthma attack (we speak of exercise-induced asthma). To avoid an asthma attack during sports, it is best to warm up well, avoid outdoor sports in cold weather, and avoid sports on days when pollution peaks. Also be careful to avoid sports with animals (horse riding, dog sports, etc.) if asthma attacks are caused by their hair.

• Enjoy the sun's rays: Ultraviolet rays (type B) from the sun are essential for the endogenous synthesis of vitamin D, it is even our main contribution. There is also no point in exposing yourself for too long when the sun is too strong. Apply sun protection with SPF (sun protection factor) greater than or equal to 50, wear long clothing and shelter from the sun as soon as possible.

• Prioritize breastfeeding for as long as possible: Non-breastfed children who are breastfed for less than 12 weeks are more likely to develop asthma as they grow up. Be careful, breastfeeding does not completely protect against asthma. If breastfeeding is impossible or unwanted, the child will not necessarily develop asthma.

• Well-managed dietary diversification: there appears to be a relationship between children's dietary diversification and the prevalence of asthma. Researchers note that the occurrence of asthma in children is inversely proportional to the number of foods introduced before one year of age. This indicates that the more new foods a child is introduced to, the less likely they are to develop asthma as they grow up.

• Weight loss : overweight and obesity are factors aggravating the prevalence and symptoms of asthma attacks. A balanced diet may be necessary to reduce the impact of asthma on daily life.

• Remember to relax: anxiety and stress are factors that increase asthma attacks (be careful, they do not cause the attack).

• The healthiest lifestyle possible : several rules of life are necessary when you suffer from asthma: regularly ventilate your home, lower the indoor temperature, improve the ventilation of your home.

• Protecting children from tobacco : passive smoking in early childhood greatly increases the risk of asthma. If you are a smoker, avoid smoking in the presence of a child and prefer to smoke outdoors. Of course, quitting smoking is the best solution.

• Think about the essential oils to relieve asthma : certain essential oils are expectorant or bronchodilator. They will help alleviate the symptoms of an asthma attack.

Coffee and ginger claim to be anti-asthma attack foods because of their potential bronchodilator effect: they stimulate the relaxation of the smooth muscles of the respiratory tract. Thus, they would directly relieve an attack by increasing the diameter of the bronchi. This property comes from their constituents: caffeine for coffee, 6-gingerol, 8-gingerol and 6-shogaol for ginger. To see more clearly, let's treat these foods separately.

There caffeine is an alkaloid from the same family as theophylline. The latter is used (in high doses) to treat asthma and obstructive bronchopathies (respiratory pathologies) because of its bronchodilator power. Caffeine would also have this effect: there is a modest improvement in respiratory function after consumption of caffeine-based products.

Consuming caffeine does not prevent or stop an asthma attack. It would just help to slightly improve the symptoms. Its action is visible up to four hours after consumption of caffeine in people with asthma.

However, the scientific data are too thin to determine the dose of caffeine required to observe its weak bronchodilator power. Coffee is not the only food containing caffeine, we also find: tea, dark chocolate, cocoa beans, cocoa powder without added sugar, guarana or mate powders.

Concerning ginger, only one study carried out in vitro on cell culture from mice and human donors indicate muscle relaxation after addition of 6-gingerol, 8-gingerol and 6-shogaol. Currently, the data is also too meager to assert that ginger resolves asthma attacks: the protocol is carried out in vitro and it only concerns three ginger molecules.

For these two foods, the results are therefore encouraging. They can be used to support conventional treatment.

Cow's milk is often singled out. This is also the case for asthma. Some popular practices support the exclusion of cow's milk in the presence of asthma. According to them, cow's milk increases the production of mucus in the respiratory tract, which worsens asthma attacks. However, no scientific data proves or observes a link between the consumption of cow's milk and the production of mucus.

This rumor is therefore unfounded. THE cow's milk is allowed when you suffer from asthma.