It is estimated that around 5-10% young patients suffer from asthma. Wheezing is one of the most common reasons that worried parents give for visiting the pediatrician. For many years the scientists have studied how to stop the allergic diseases epidemic. Unfortunately, many scientific findings seem opposing. Swedish researchers (1) observed that broad-spectrum antibiotic administration in the first week of neonate’s life increases the risk of wheeze in preschool children. Moreover early introduction of fish into infant’s diet results in decreased frequency of asthma in 4 year-olds.
Risk factors for asthma
According to the guidelines given by the Global Strategy for Asthma Management and Prevention (GINA – 2008 update), factors affecting the development and manifestation of asthma can be divided into individual and environmental. Among the first ones we find genetic predisposition, obesity and sex. It turns out that asthma is diagnosed 2 times more often among boys than girls before their 14th birthday(2). Environmental factors include exposure to alergens, tobacco, air pollution and diet.
Prevention of pediatric asthma
Current recommendations (3) concerning the prophylaxis of asthma in children indicate the necessity of total elimination of smoke exposure to the fetus and the child. Allergen-free diet in pregnancy and lactation is not recommended. However breast-feeding is promoted for at least 4 first months of infant’s life. As a result, the reduction of asthma prevalence in 4-years-olds can be achieved (4). Exposure to house dust mites should be eliminated as part of secondary prevention, but not primary. The other way round – avoidance of pets’ fur allergens is crucial in secondary prevention and not primary. Much is spoken about the protective influence of probiotics and vitamin D supplementation, but the scientific findings are not convincing.
Relationship between antibiotics and asthma
Over 5 years ago it was found that antibiotic administration during infancy is connected with higher prevalence of asthma in older children (5). Apparently, earlier antibiotic intake in neonates’ first week of life may also lead to asthma (1). Among children in preschool age, who underwent 3 episodes of wheezing in the last year, as much as 10% had been administered broad-spectrum antibiotics in the first week post partum. The authors mention the so-called “reverse causation” phenomenon. It can be easily presumed that antibiotics cause asthma, but we cannot exclude the possibility that atopy can cause the more frequent need of antibiotic use.
Allergic parents , hence the children take antibiotics
Children of individuals who suffer from asthma can be characterized by impaired maturation of immunological system (6). It was confirmed by means of cytokine analysis of umbilical cord blood and in vitro tests evaluating the reaction of white blood cells to pathogens. Then again, impaired immunological system maturation confirmed at birth or during the early postnatal life may result in asthma and infectious lower respiratory tract infections in older children (7). This is the reason for the scientists’ circumspection and taking into consideration the possibility of “reverse causation”.
Antibiotics influence the maturation of immunological system
On the other hand it is generally known, that wide-spectrum antibiotics cause long-standing changes in the alimentary tract microflora. In case of young organisms, whose immunity is immature, antibiotics impair the mucosal immunological function and may disable the formation of immunological tolerance (8). It may lead to excessive reaction to food allergens, immunization and manifestation of allergic diseases. In young mice which underwent antibiotic therapy in their early postnatal life, impaired intestinal barrier was found along with Th2 polarization of immunologic system, which is characteristic for allergy (9). However, it is important to point out, that antibiotic administration in neonatology is usually justified so in this case the avoidance of drug use is not suggested.
Can fish products help prevent asthma?
Discussed publication confirms the beneficial effects of fish consumption on child’s immunological system (1). Some studies indicate that high supply of fish products to pregnant women and infants reduces the risk of allergy manifestation in later life (10). It is speculated that the major role is played by polyunsaturated fatty acids (PUFA) ω 3, which fish are especially rich of. They are thought to antagonize PUFA ω 6 whose higher ratio towards the ω 3 may lead to the development of allergic diseases (11). In fact, early introduction of fish products to infant diet results in the decrease of allergic eczema in infants and allergic rhinitis in preschool children (12). The same may concern asthma in 4-year-olds (13). Some scientist believe that the effects are not provided solely by PUFA ω 3 but other unknown substances contained in fish meat , as the attempts with the supplementation of just PUFA ω 3 do not present such spectacular outcomes (14).
Antibiotic administered? Introduce fish quickly
It was observed that the risk of recurrent wheezing in 4-year old children exposed to antibiotics in their first week was lower for those who started to eat fish early, before the end of the 9th month of their life (1). Although in the statistic analysis the p value did not reach the significance point (p= 0.084), we can hope for the confirmation of this relationship in next studies. Much time will pass before the above-mentioned ideas appear in the official guidelines. The function of immunological system and its pathologies is still too scarcely discovered. May be one day we shall stop the epidemic of allergic diseases and protect the youngest patients from asthma.
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3.Anna Bręborowicz. Postępy w pulmonologii i alergologii dziecięcej w 2010 roku. Medycyna Praktyczna Pediatria 2011/04
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6.Gold DR et al. Parental characteristics, somatic fetal growth, and season of birth influence innate and adaptive cord blood cytokine responses. J Allergy Clin Immunol 2009;124: 1078–87.
7.Zhang G et al. Interleukin-10 ⁄ interleukin-5 responses at birth predict risk for respiratory infections in children with atopic family history. Am J Respir Crit Care Med 2009; 179: 205–11.
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11.Kremmyda LS et al. Atopy risk in infants and children in relation to early exposure to fish, oily fish, or long-chain omega-3 fatty acids: a systematic review. Clin Rev Allergy Immunol 2009.
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13.Nafstad P et al. Asthma and allergic rhinitis at 4 years of age in relation to fish consumption in infancy. J Asthma 2003; 40: 343–8.)
14.Marks GB, Mihrshahi S, Kemp AS et al. Prevention of asthma during the first 5 years
of life: a randomized controlled trial. J Allergy Clin Immunol 2006; 118: 53–61.
Want to know more about asthma? Watch on medtube.net: “Asthma – 3D animation”