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

Abstract

There are two main families of polyunsaturated fatty acids (PUFAs), the n-6 and the n-3 families. It has been suggested that there is a causal relationship between n-6 PUFA intake and allergic disease, and there are biologically plausible mechanisms, involving eicosanoid mediators of the n-6 PUFA arachidonic acid, that could explain this. Fish and fish oils are sources of long-chain n-3 PUFAs and these fatty acids act to oppose the actions of n-6 PUFAs. Thus, it is considered that n-3 PUFAs will protect against atopic sensitization and against the clinical manifestations of atopy. Evidence to examine this has been acquired from epidemiologic studies investigating associations between fish intake in pregnancy, lactation, infancy, and childhood, and atopic outcomes in infants and children and from intervention studies with fish oil supplements in pregnancy, lactation, infancy, and childhood, and atopic outcomes in infants and children. All five epidemiological studies investigating the effect of maternal fish intake during pregnancy on atopic or allergic outcomes in infants/children of those pregnancies concluded protective associations. One study investigating the effects of maternal fish intake during lactation did not observe any significant associations. The evidence from epidemiological studies investigating the effects of fish intake during infancy and childhood on atopic outcomes in those infants or children is inconsistent, although the majority of the studies (nine of 14) showed a protective effect of fish intake during infancy or childhood on atopic outcomes in those infants/children. Fish oil supplementation during pregnancy and lactation or during infancy or childhood results in a higher n-3 PUFA status in the infants or children. Fish oil provision to pregnant women is associated with immunologic changes in cord blood and such changes may persist. Studies performed to date indicate that provision of fish oil during pregnancy may reduce sensitization to common food allergens and reduce prevalence and severity of atopic dermatitis in the first year of life, with a possible persistence until adolescence with a reduction in eczema, hay fever, and asthma. Fish oil provision to infants or children may be associated with immunologic changes in the blood but it is not clear if these are of clinical significance and whether they persist. Fish oil supplementation in infancy may decrease the risk of developing some manifestations of allergic disease, but this benefit may not persist as other factors come into play. It is not clear whether fish oil can be used to treat children with asthma as the two studies conducted to date give divergent results. Further studies of increased long-chain n-3 PUFA provision in during pregnancy, lactation, and infancy are needed to more clearly identify the immunologic and clinical effects in infants and children and to identify protective and therapeutic effects and their persistence.

Use of a common food frequency questionnaire (FFQ) to assess dietary patterns and their relation to allergy and asthma in Europe: pilot study of the GA2LEN FFQ

“…The study aimed specifically at validating the intake of n-3 FAs, as these have a potential role in asthma and allergic diseases (Kremmyda et al, 2009). We found a good level of repeatability in the FFQ, although we found evidence that intakes from FFQ t1 were systematically and significantly higher than intakes from FFQ t2 in most centres and in the total sample.…”

Fatty Acids as Biocompounds: Their Role in Human Metabolism, Health and Disease - A Review. Part 2: Fatty Acid Physiological Roles and Applications in Human Health and Disease

“…It is now considered that supply of EPA and DHA to the fetus might be important in promoting appropriate immune development 117,118 . With regard to the latter, there is some evidence that early fish and LC n-3 PUFA exposure protects against immune dysfunctions like sensitisation to allergens (atopy), allergy and asthma in infancy and childhood 119 . Epidemiological studies looking at the effect of maternal fish consumption during pregnancy and fish consumption during infancy/childhood suggest that fish consumption may play a protective role against atopic disease development in children.…”

Paediatrics in Barcelona

“…GOKSÖ R et al [138] confirmed that the protective effect of early (before 9 months of life) fish introduction into an infant's diet against wheezing in early childhood is also present for atopic asthma at school age. A recent systematic review, however, concluded that the evidence is inconsistent from the epidemiological studies investigating the effects of fish intake during infancy and childhood on atopic outcomes in infants or children, and that further studies are needed [139]. Finally, in the context of the PASTURE (Protection against Allergies Study in Rural Environments) birth cohort study conducted in five European countries, RODUIT et al [140] showed that an increased diversity of foods introduced in the first year of life had a significant protective effect against the later development of asthma, food allergy and food sensitisation, and that reduced food diversity was associated with reduced expression of Foxp3.…”