February 20, 2007 — A maternal diet with high intake of margarine, vegetable oils, and citrus fruit during the last 4 weeks of pregnancy is linked with eczema in children by 2 years of age, according to the results of a study reported in the February issue of the American Journal of Clinical Nutrition.

"Maternal diet during pregnancy might be one of the factors that influences fetal immune responses associated with childhood allergy," write Stefanie Sausenthaler, of the Institute of Epidemiology in Neuherberg, Germany, and colleagues from the LISA (Influences of Lifestyle-related Factors on the Immune System and the Development of Allergies in Childhood) Study Group. "Postnatally, a high dietary intake of n-6 polyunsaturated fatty acids (PUFAs) has been shown to be associated with an increased risk of allergic diseases because of their proinflammatory properties, whereas n-3 PUFAs and dietary antioxidants are supposed to have a protective effect on asthma and allergies. Although there is a biological basis for a prenatal effect of dietary factors on the development of allergic diseases, the number of studies investigating this subject is very limited."

Using a German prospective birth cohort study (LISA), the investigators analyzed data from 2641 children at 2 years of age. A semiquantitative food-frequency questionnaire administered shortly after childbirth was used to evaluate maternal diet during the last 4 weeks of pregnancy.

During the last 4 weeks of pregnancy, high maternal intake of margarine (adjusted odds ratio [aOR], 1.49; 95% confidence interval [CI], 1.08 - 2.04) and vegetable oils (aOR, 1.48; 95% CI, 1.14 - 1.91) was positively associated with eczema in the children by 2 years of age. In contrast, high maternal fish intake was inversely associated with this risk (aOR, 0.75; 95% CI, 0.57 - 0.98). High intake of celery (aOR, 1.85; 95% CI, 1.18 - 2.89) and citrus fruit (aOR, 1.73; 95% CI, 1.18 - 2.53) was associated with increased risk for sensitization against food allergens. Sensitization against inhalant allergens was associated positively with a high maternal intake of deep-frying vegetable fat (aOR, 1.61; 95% CI, 1.02 - 2.54), raw sweet pepper (aOR, 2.16; 95% CI, 1.20 - 3.90), and citrus fruit (aOR, 1.72; 95% CI, 1.02 - 2.92).

"We suggest that the intake of allergenic foods and foods rich in n-6 polyunsaturated fatty acids during pregnancy may increase and foods rich in n-3 polyunsaturated fatty acids may decrease the risk of allergic diseases in the offspring," the authors write.

Study limitations include possible misclassification of dietary exposure, lack of data on usual serving sizes, inability to rule out that the reported associations were modified by the diet of the children during the first 2 years of life, inability to evaluate the health effect of each single food, possible reverse causation if atopic mothers altered their diet during pregnancy to avoid known food allergens, and insufficient power to identify more specific associations between single foods and specific food sensitization.

"Currently, no recommendations are being made to mothers to modify their diets to prevent allergies in their children because of insufficient evidence of a beneficial effect," the authors conclude. "However, before any recommendations can be made, randomized clinical intervention trials should be performed to confirm the cause-effect relation observed in the present study."

The Federal Ministry for Education, Science, Research, and Technology supported this study. The authors have disclosed no relevant financial relationships.

Am J Clin Nutr. 2007;85:530-537.

Study Highlights
Of 3097 newborns enrolled in previous study, 2664 participated at age 24 months and 2641 met enrollment criteria.
Exclusion criteria included chronic disease, lack of maternal diet information, and no response to the 24-month survey.
Participants and excluded subjects were similar in sex, birth weight, and birth season.
Compared with excluded subjects, participants were more likely to live in Munich, to have older mothers, parents with higher level of education, and at least 1 parent with atopic disease, and to be breast-fed for at least 4 months. They were less likely to have mothers who smoked during pregnancy and to have 2 or more older siblings.
Maternal food intake of 26 food items during the last 4 weeks of pregnancy was obtained by food-frequency questionnaire following delivery (median, 3 days).
Total and specific IgE levels were obtained at age 24 months.
Parents reported clinician-diagnosed "allergic or atopic eczema in the past 6 months" for 17.7% of children.
Food allergen sensitization, defined by specific serum IgE of at least 0.35 kU/L against food allergens (egg, cow milk, wheat, peanut, soybean, and codfish) was found in 9.3% of children.
The most common food allergens were egg in 5.4% and milk in 5.1%.
Inhalant allergen sensitization was defined by specific serum IgE of at least 0.35 kU/L against house dust allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, German cockroach, house dust); cat dander; mixed molds (Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatus, Alternaria alternata); or seasonal allergens (timothy grass, mugwort, English plantain, ribwort, wall pellitory, birch pollen).
Most common inhalant allergen was house dust in 2.8%.
Maternal diet was linked to study area, maternal age at delivery, maternal smoking during pregnancy, parental education, and duration of exclusive breast-feeding.
Odds ratios were adjusted for study area, sex, maternal age at delivery, smoking during pregnancy, parental education, exclusive breast-feeding for at least 4 months, family history of atopy, birth season, and dietary variables.
Eczema was positively associated with high maternal intake of margarine (aOR, 1.49; 95% CI, 1.08 - 2.04) and vegetable oils (aOR, 1.48; 95% CI, 1.14 - 1.91).
Eczema was negatively associated with high maternal intake of fish (aOR, 0.75; 95% CI, 0.57 - 0.98).
Food allergen sensitization was positively associated with high maternal intake of celery (aOR, 1.85; 95% CI, 1.18 - 2.89) and citrus fruit (aOR, 1.73; 95% CI, 1.18 - 2.53).
Inhalant allergy sensitization was positively associated with high maternal intake of deep-frying vegetable fat (aOR, 1.61; 95% CI, 1.02 - 2.54), raw sweet peppers (aOR, 2.16; 95% CI, 1.20 - 3.90), and citrus fruit (aOR, 1.72; 95% CI, 1.02 - 2.92).
High cream intake was associated with increased risk for cow milk sensitization (aOR, 1.62; 95% CI, 1.07 - 2.45).
Egg intake was not associated with egg sensitization.
Study limitations included possible misreporting of dietary intake and effect of children's diet in the first 2 years.
Authors suggest randomized trials to confirm results prior to making recommendations for maternal dietary intake.