Diet and Asthma

Asthma is a fairly widespread chronic inflammatory disease that affects the respiratory tract ; the symptoms are rather variable ( dyspnea , cough , chest tightness and breathing difficulty ), but are usually associated with reversible obstruction of the air flow and bronchospasm .
The causes are unclear and probably mixed between genetic and other environmental factors.

Diagnosis is usually based on symptoms, response to drug therapy, and spirometry .
Asthma is classified based on the frequency of symptoms, forced expiratory volume in the first second (FEV1), and peak expiratory flow (detected with spirometry).

Asthma can also be divided into atopic (extrinsic) and non-atopic (intrinsic), where atopic refers to the predisposition to the development of allergic reactions (type 1 hypersensitivity); in this type of asthma, it is possible that the incorrect diet plays a predisposing role .
The pharmacological treatment of acute symptoms occurs via the inhalation route of beta-2 agonist drugs and the oral route of corticosteroids ; in very severe cases, they can be injected during hospitalisation.
Prevention of acute illnesses requires avoiding the triggering mechanism, for example contact with allergens or irritants; you can choose to make constant pharmacological use of inhaled corticosteroids, sometimes supported by long-acting beta agonists or antileukotriene drugs .
Worldwide diagnoses of asthma have increased significantly since 1970. In 2011, 235-300 million people were recognized as asthmatic and 250,000 died.
Based on what has been said so far, asthma would seem to be a disease that only affects the respiratory tract. However, some forms are significantly affected by certain oral allergenic factors, relative cross-reactivity and other predisposing conditions; some of these concern the etiological mechanism of bronchoconstriction, others significantly emphasize the complications of the pathology itself.

Asthma and Nutrition during Pregnancy or Breastfeeding

We specify that asthma can have a rather important genetic (hereditary) and familial basis, which is why certain women tend to make rather significant lifestyle changes right from conception .
First of all, for the sake of correct disclosure, we would like to remind you that blocking drug therapy by increasing the risk of fetal hypoxemia (due to poor pathological control or potential serious exacerbations) is considered a very risky attitude . Instead, it is advisable to take the usual medications in minimal doses and in the presence of continuous medical monitoring. As far as nutrition is concerned , however, there are still many doubts. Many believe that food prevention from asthma begins with pregnancy and breastfeeding. This is why some pregnant women or nurses avoid the intake of potentially allergenic foods , adopting the so-called ” elementary hypoallergenic diet “.

On the other hand, no statistical correlation has yet been demonstrated between this nutritional style and the reduction in the incidence of asthma (in the mother or child). Since it is a highly restrictive diet (potentially subject to nutritional deficiency ), almost all doctors suggest not using it unless there are well-defined risk factors (e.g. familiarity with a particular allergy).
In the nurse, the diet free of potentially allergenic molecules has a much higher value. It serves to avoid contact between the newborn and some allergens which could prove fatal (due to anaphylactic reaction ) but, even in this case, it has less to do with the onset of asthma than the more serious cases of food allergy .
NB . Breastfeeding rather than artificial feeding represents a preventive factor against any disease.

Asthma and Obesity

A more than significant correlation has been highlighted between the onset of obesity and the diagnostic incidence (or worsening) of the asthmatic condition (especially in recent years).
Among the factors responsible for this correlation we highlight above all:

• a reduction in respiratory function due to fat accumulation
• and the metabolic pro-inflammatory state induced by excess adipose tissue(common to asthma).

Furthermore, the comorbidity between asthmatic disease and severe overweight can be referred to the so-called “Western lifestyle”, i.e.: physical inactivity , few antioxidants and long stay in closed environments.
Ultimately, obesity represents a non-allergic factor, predictive and independent of others regarding the onset of asthma.

Asthma and Antioxidants

Another dietary factor that appears to alter the incidence and severity of asthma is the presence of antioxidants.
The group of antioxidants is chemically very heterogeneous; it has the function of limiting oxidative stress by intervening at various levels (based on the specific molecule), but the action of the single element is amplified by that of all the others.
Without going into too much detail, let’s remember that antioxidants can be endogenous (produced by the body) and exogenous (taken with food ) . Obviously, the greater the proportion of molecules introduced with the diet, the higher the defensive level.
In addition to fighting free radicals , antioxidants are able to exert an anti-inflammatory , anti-tumor, hypocholesterolemic , hypoglycaemic , protective action against atherosclerosis , etc.
Antioxidants play a protective role against asthma thanks to their ability to prevent systemic inflammation which, as we have seen in obesity, is involved in the etiology of this disorder.
The most common food antioxidants are:

• Vitaminics: provitamin A ( carotenoids ), vitamin C ( ascorbic acid ) and vitamin E (tocopherols or tocotrienols)
• Mineral salts: Zinc and Selenium
• Phenolic substances: anthocyanins, flavonoids , flavones, phenolic acids, phenolic alcohols, secoridoids, hydroxycyanimide acids etc.
• Tannins
• Chlorophyll
• Melanoidins
• Caffeineand the like.

Asthma and Allergens

Almost all allergens are substances naturally present in the environment that enter the body through inhalation, food or drugs. It is therefore reasonable to deduce that food allergens – in particular those of eggs , milk , nuts and fish – can also cause the onset of asthma.
On the other hand, it has not yet been demonstrated that allergens present in foods have the power to independently trigger asthma-type symptoms.
In occupational asthma (different from the aggravation of a pre-existing form), a certain incidence is found among operators who work in food establishments ( flour production – baker’s asthma ) or food additives . These forms, together with other types of occupational asthma, constitute up to 15% of the total.

Asthma and Food Additives

Once again responsible for adverse effects on human health, some food additives have been accused of triggering respiratory crises (acute dyspnoea).
Among these, preservatives and colorants are especially involved , potentially responsible for bronchospasm.
It seems that poor tolerance or excessive intake of sulphites can induce bronchoconstriction similar to a real asthma attack; the most harmful forms are those of sodium and potassium metabisulphites , or E223 and E224, used above all in winemaking.
Not only that, even the azo dye E107 or Yellow 2G can trigger bronchial symptoms similar to asthmatic status; this synthetic additive is used to color foods yellow, such as, for example, mayonnaise .

Asthma and Diet

Due to concerns about the side effects of drugs used to treat asthma , scientific progress has been directed towards finding foods or nutrients capable of controlling the onset and worsening of asthma.
These dietary interventions are mainly aimed at reducing the global inflammatory response . A 2014 experimental study entitled “Dietary interventions in asthma” revealed that saturated fatty acids can increase the inflammatory response by activating “pattern recognition” receptors.
On the contrary, omega-3 polyunsaturated fatty acids can have an anti-inflammatory action through mechanisms that modify the production of good eicosanoids . Furthermore, the antioxidants we talked about in the previous chapters can exert significant anti-inflammatory effects such as, for example, the elimination of free radicals (preventing the activation of certain transcription factors such as NF-kB). Finally, as anticipated, obesity is able to increase systemic inflammation due to the release of chemical mediators by adipose tissue. From what was mentioned in the previous chapters and based on what was specified in the research, it seems clear that a good diet against asthma must have the following characteristics:

• Caloriesneeded to maintain weight or reduce it (if it is excessive)
• Increase in physical activitydesirable (if tolerated)
• Prevalence of unsaturated fatty acidsover saturated ones with emphasis on the polyunsaturated intake of the omega-3 group ( alpha-linolenic , EPA and DHA )
• Reduction, not only percentage but absolute, of saturated fats
• Increase, not only percentage but absolute, in omega-3 fats
• Richness in antioxidants with anti-inflammatory action such as, for example, vitamins, minerals and phenolic ones
• Absence of food additives potentially harmful to asthma.

In practical terms it is possible to state that:

• If the weight is excessive, the asthma diet must promote weight lossin association with a physical activity protocol established with the doctor and a sports coach
• Eliminate all fatty cheeses, many of the mature ones and fatty meats (which especially include cured meats , fresh sausages , bacon , ribs, etc.)
• Prefer white meatsand fish; these, if rich in omega-3, can also be granted with higher fat percentages
• Season only with extra virgin olive oilor, at most, with other cold-pressed vegetable oils rich in antioxidants, phytosterols and unsaturated fats
• Consume at least 2 servings of vegetablesand 2 of fruit per day
• Minimize processed, refined and packaged foods
• Eliminate wines containing sulphites; at most, prefer organicor biodynamic ones.