Late introduction of fish and eggs is associated with increased risk of allergy development – results from the FARMFLORA birth cohort

Abstract

The prevalence of allergy is markedly low in children growing up on farms. An increasing number of studies indicate that the timing of food introduction may affect allergy development. We aimed to investigate if protection against allergy in farm environments may be mediated through differences in food-introduction practices between farm and non-farm families, using an explorative approach. Twenty-eight farm and 37 non-farm children were included in the FARMFLORA birth cohort. Practices of breastfeeding and introduction of formulas and complementary foods were collected by questionnaires at 6, 12, and 18 months of age. Allergy was diagnosed by pediatricians at 3 years of age. The only difference in food-introduction practices observed between farm and non-farm children was an earlier introduction of nuts in farmers (median month: 11 [IQR: 8–6] in farmers, 15 [12–19] in non-farmers). One farm child (4%) and 10 non-farm children (27%) were allergic at 3 years of age. Lower risk of allergy development was associated with early exclusive breastfeeding (continuous variable; OR = 0.59, 95% CI: 0.39–0.89), but also having received eggs (OR = 0.08, 95% CI: 0.13–0.54) and fish (logistic regression not applicable, P = 0.01 in likelihood ratio testing [χ2]) at 10 months of age or earlier compared to later. Our results were not affected by reverse causation, as judged by a questionnaire sent to the families in retrospect. Timing of introduction of complementary foods is unlikely to contribute to the lower risk of allergy among farm children. Although early exclusive breastfeeding was associated with a lower rate of allergy development, postponed introduction of complementary foods might increase the risk of developing allergy. Owing to the limited sample size, our results are only indicative, but support prior findings.

Fecal short chain fatty acids in children living on farms and a link between valeric acid and protection from eczema

“…There were fewer boys in the farm group than in the rural control group (36% vs. 62%, P = 0.04), and farm children more often had a cat or dog (75% vs. 51%, P = 0.054). Farm children consumed more full-fat milk products and less margarine and oils compared with the rural control children, as reported previously 8 , 19 . At 1 year of age, farm children also consumed more oily fish ( P = 0.02) and farm milk ( P < 0.01), while control children consumed more poultry ( P = 0.03) 8 , 19 .…”

Cord Blood Levels of EPA, a Marker of Fish Intake, Correlate with Infants’ T- and B-Lymphocyte Phenotypes and Risk for Allergic Disease

“…The FARMFLORA birth-cohort study comprises 28 families who live on small, family-owned dairy farms in the Skaraborg County of southwest Sweden and 37 non-farming control families from the same rural areas [ 2 , 7 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Pregnant women were recruited at maternity clinics in the Skaraborg region in the period between September 2005 and May 2008.…”

Appropriate age range for introduction of complementary feeding into an infant's diet

“…Only single studies were available to assess the timing of introduction of specific foods, i.e. egg (Halpern et al., ) and cereals (Jonsson et al., ) (both supportive line of evidence) (Annex A as Microsoft Excel ® file). Therefore, these cannot be used to establish the appropriate age range of introduction of CFs and were not considered further.…”

“…( 2004 ) 3 PCMulticenter Allergy Study (MAS)NoCFEczemaAtopic dermatitisNo PE Jonsson et al. ( 2017 ) 2 PCFARM‐FLORANoCerealsAtopic diseaseAtopic diseaseCV Joseph et al. ( 2011 ) 2 PCWayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS)No/YesCFSensitisationsIgE Kajosaari and Saarinen ( 1983 ) 3 PCn/aYesCFEczemaAtopic dermatitis Food allergySymptomatic food allergy Kajosaari ( 1991 , 1994 ) 3 PCn/aYesCFAsthma‐like symptomsAsthma Atopic diseaseAtopic disease EczemaAtopic dermatitis Keijzers et al.…”