Asthma
Asthma is a fairly common chronic inflammatory disease that affects the respiratory tract; the symptoms are quite variable (dyspnea, cough, chest tightness and difficulty breathing), but in custom they are associated with reversible airflow obstruction and bronchospasm.
Diagnosis is usually based on symptoms, response to drug therapy and spirometry.
Asthma is classified according to the frequency of symptoms, the forced expiratory volume in the first second (FEV1) and the peak expiratory flow (detected with spirometry).
Asthma can also be divided into atopic (extrinsic) and non-atopic (intrinsic), where by atopic we mean the predisposition to the development of allergic reactions (type 1 hypersensitivity); in this type of asthma, it is possible that the incorrect diet has a predisposing role .
The pharmacological treatment of acute symptoms occurs by inhalation of beta-2 agonist drugs and by the oral route of corticosteroids; in very serious cases, they can be injected during hospitalization.
Acute prevention requires avoiding the triggering mechanism, such as contact with allergens or irritants; you can choose to make a constant pharmacological use of inhaled corticosteroids, sometimes supported by long-lasting beta-agonists or antileucotrienici.
World diagnoses of asthma have increased significantly since the 1970s. In 2011, 235-300 million people were recognized as asthmatics and 250, 000 died.
Based on what has been said so far, asthma would appear to be a disease that affects only the respiratory tract. However, some forms suffer a lot from certain oral allergizing factors, relative cross-reactivity and other predisposing conditions; some of these affect the aetiological mechanism of bronchoconstriction, others significantly emphasize the complications of the pathology itself.
Asthma and Nutrition in Pregnancy or Lactation
We specify that asthma can have a rather important genetic (hereditary) and family basis, which is why some women tend to make quite relevant lifestyle changes from conception.
First of all, for informational correctness, let us remember that blocking drug therapy by increasing the risk of hypoxemia of the fetus (due to poor pathological control or with regard to potential serious exacerbations) is considered a very risky attitude. It is instead advisable to take customary drugs at minimum doses and in the presence of continuous medical monitoring.
With regard to food, however, there are still many doubts. Many believe that the prevention of food from asthma already starts from pregnancy and breastfeeding. This is why some pregnant or nursing mothers avoid the intake of potentially allergenic foods by adopting the so-called " hypoallergenic elementary diet ".
On the other hand, no statistical correlation between this nutritional style and the reduction in the incidence of asthma (in the mother or child) has yet been demonstrated. Since this is a highly restrictive diet (potentially subject to nutritional deficiency), almost all doctors suggest not using it unless there are well-defined risk factors (eg familiarity for a particular allergy).
In the nurse, the diet without potentially allergenic molecules has a much higher value. It serves to avoid contact between the newborn and some allergens that could prove fatal (due to an anaphylactic reaction) but, even in this case, has less to do with the onset of asthma than the more serious cases of food allergy.
NB . Breastfeeding rather than artificial breastfeeding is a preventive factor from any disease.
Asthma and Obesity
A more than significant correlation between the onset of obesity and the diagnostic (or worsening) incidence of the asthmatic condition (especially in recent years) has been highlighted.
- a reduction in respiratory function due to fat accumulation
- and the pro-inflammatory metabolic state induced by excess adipose tissue (common to asthma).
Furthermore, the comorbidity between severe asthmatic and overweight disease can be referred to the so-called "western lifestyle", ie: physical inactivity, few antioxidants and long stay indoors.
Ultimately, obesity is a non-allergic, predictive and independent factor with respect to asthma emergence.
Asthma and Antioxidants
Another dietary factor that seems to alter the incidence and severity of asthma is the presence of antioxidants.
The group of antioxidants is chemically very heterogeneous; 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 too far in detail, let us remember that antioxidants can be endogenous (produced by the body) and exogenous (taken with food). Obviously, the higher the proportion of the 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, hypoglycemic, protective action against atherosclerosis, etc.
Antioxidants play a protective role against asthma due 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:
- Vitamin: 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, hydroxicianimidic acids, etc.
- Tannins
- Chlorophyll
- melanoidins
- Caffeine and the like.
Asthma and Allergens
Almost all allergens are substances naturally present in the environment that enter the body by inhalation, with food or with drugs. It is therefore legitimate to deduce that even food allergens - in particular those of eggs, milk, nuts and fish - can determine the onset of asthma.
On the other hand, it has not yet been shown that the allergens present in food have the power to trigger an asthmatic type of symptoms independently.
In asthma of a professional nature (different from the aggravation of a pre-existing form), there is a certain incidence among operators who work in food establishments (production of flour - 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 blamed for triggering respiratory crisis (acute dyspnea).
Among these, preservatives and dyes are involved, potentially responsible for bronchospasm.
It seems that the poor tolerance or excessive intake of sulphites may induce a bronchoconstriction overlapping a real asthma attack; the most harmful forms are those of sodium and potassium metabisulfites, or E223 and E224, used above all in winemaking.
Not only that, even the azo dye E107 or Giallo 2G can trigger a bronchial symptomatology similar to the asthmatic state; this synthetic additive is used to color foods such as mayonnaise yellow.
Asthma and Diet
Due to concerns about the side effects of medications useful for treating asthma, scientific progress has been directed towards research into foods or nutrients that can control the onset and aggravation of asthma.
These dietary interventions are mainly aimed at reducing the global inflammatory response. A 2014 trial entitled "Dietary interventions in asthma" revealed that saturated fatty acids can increase the inflammatory response by activating "pattern recognition" receptors.
Moreover, the antioxidants that we discussed in the previous chapters can exert remarkable anti-inflammatory effects such as, for example, the cancellation 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 is specified in the research, it seems clear that a good diet against asthma should have the following characteristics:
- Calories needed to maintain weight or reduce it (in case it is excessive)
- Increased physical activity desirable (if tolerated)
- Prevalence of unsaturated fatty acids on saturated with emphasis on the contribution of polyunsaturated omega-3 (alpha-linolenic, EPA and DHA)
- Not only a percentage but absolute reduction of saturated fats
- Increased, not only percentage but absolute, of omega-3 fats
- Richness of antioxidants with anti-inflammatory action such as, for example, vitamin, mineral 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 should promote weight loss in association with a motor activity protocol established with the attending physician and a sports technician
- Eliminate all the fatty cheeses, many of the seasoned ones and the fatty meats (of which they are part above all the salami, the fresh sausages, the pancetta, the ribs etc)
- Prefer white meat and fish; these, if rich in omega-3, can also be given with higher percentages of fat
- Season only with extra virgin olive oil or, at the limit, with other cold-pressed vegetable oils rich in antioxidants, phytosterols and unsaturated fats
- Consume at least 2 servings of vegetables and 2 of fruit per day
- Minimize processed, refined and packaged foods
- Eliminate wines containing sulphites; to the limit, prefer biological or biodynamic.
Bibliography:
- Dietary factors lead to innate immune activation in asthma - Wood LG, Gibson PG (July 2009) - Pharmacol. Ther.123 (1): 37–53.
- Dietary interventions in asthma - Scott HA, Jensen ME, Wood LG - Curr Pharm Des. 2014; 20 (6): 1003-10.
