***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective : To evaluate whether levels of n-6 long chain polyunsaturated fatty acids ( LCPs ) in human breast milk are related to the mother ’s atopic constitution , and whether a decreased level can be restored by gamma-linolenic acid supplementation . Design : Cross-sectional study and dietary supplementation trial . Subjects : 20 atopic mothers and 20 non-atopic mothers ( controls ) , all lactating . Setting : General population . Interventions : The atopic mothers were r and omly assigned to low ( n=10 ) or high ( n=10 ) dosage oral supplementation with oral borage oil for one week ( 230 or 460 mg gamma-linolenic acid ( 18:3n-6 ) per day).Main outcome measures : Essential fatty acid composition of the breast milk total fat fraction , determined by gas liquid chromatography . Results : Arachidonic acid ( 20:4n-6 ) was lower in breast milk of atopic mothers compared with non-atopic mothers ( 0.39 wt% vs 0.46 wt% , difference −0.07 % wt% ( 95 % confidence limits −0.13 , −0.01 wt% ; P<0.05 ) . The ratio between linoleic acid and the sum of n-6 derivatives did not differ between these groups , indicating no difference in delta-6-desaturase ( D6D ) activity . Supplementation of the atopic mothers significantly increased the levels of gamma-linolenic acid and dihomo-gamma-linolenic acid in breast milk in a dose-related way , but the level of arachidonic acid was not increased . Conclusion : We found a decreased level of arachidonic acid in breast milk in atopic compared to non-atopic mothers , but no indication that the rate-limiting enzymatic step ( D6D ) is involved . Supplementation increased the precursor pool but did not restore the level of arachidonic acid . We conclude that atopy is related to a metabolic disturbance beyond the D6D enzymatic step . A low level of arachidonic acid in breast milk may be a risk factor for the development of atopy in the infant , especially when the possible underlying metabolic disturbance of EFA metabolism is inherited by the child . Sponsorship : F Hoffman-La Roche ( Basel , Switzerl and ) and Friesl and Dairy Foods ( Leeuwarden , The Netherl and s).European Journal of Clinical Nutrition ( 2000 ) 54 , BACKGROUND There is controversy regarding the relationship of the effect of breast-feeding on markers of allergy such as total serum IgE in childhood . OBJECTIVE This study , using longitudinal data , tested the hypothesis that the relation of breast-feeding to IgE in childhood differs depending on maternal total IgE level . METHODS Total serum IgE was assessed with the paper radioimmunosorbent test at 4 ages in nonselected children enrolled at birth into the prospect i ve Tucson Children 's Respiratory Study . Children were classified as never breast-fed , breast-fed less than 4 months , or breast-fed 4 months or longer , on the basis of physician report or question naires completed by parents by the time the child was 18 months old . A longitudinal r and om effects model was used to test for group differences and temporal trends in IgE for children classified with reference to maternal IgE ( high tertile vs all others ) and breast-feeding history . A total of 664 children with 1457 observations were included . RESULTS Among children whose mothers were in the 2 lower tertiles of IgE , breast-feeding was associated with lower total serum IgE at age 6 years ( 24.2 vs 44.3 IU/mL for never breast-fed children ; P < .02 ) ; similar trends existed at age 11 years . In contrast , for children whose mothers were in the highest tertile of IgE , breast-feeding of 4 months or longer was associated with higher IgE levels in the child compared with those never breast-fed or breast-fed less than 4 months ( 97.0 vs 38.9 IU/mL ; P < . 005 ) . These cross-sectional analyses were confirmed with the longitudinal r and om effects model , which also showed no effect of confounders . Paternal IgE showed no similar relation with child IgE. CONCLUSION Breast-feeding appears to have paradoxic relations with IgE in childhood , depending on maternal IgE level . These findings may help explain the contradictory results found in other investigations of the relation of breast-feeding to allergic symptoms and markers BACKGROUND Opinions and recommendations about the optimal duration of exclusive breastfeeding have been strongly divided , but few published studies have provided direct evidence on the relative risks and benefits of different breastfeeding duration s in recipient infants . OBJECTIVE We examined the effects on  infant growth and health of 3 compared with 6 mo of exclusive breastfeeding . DESIGN We conducted an observational cohort study nested within a large r and omized trial in Belarus by comparing 2862 infants exclusively breastfed for 3 mo ( with continued mixed breastfeeding through > /= 6 mo ) with 621 infants who were exclusively breastfed for > /= 6 mo .  Regression to the mean , within-cluster correlation , and cluster- and individual-level confounding variables were accounted for by using multilevel regression analyses . RESULTS From 3 to 6 mo , weight gain was slightly greater in the 3-mo group [ difference : 29 g/mo ( 95 % CI : 13 , 45 g/mo ) ] , as was length gain [ difference : 1.1 mm ( 0.5 , 1.6 mm ) ] , but the 6-mo group had a faster length gain from 9 to 12 mo [ difference : 0.9 mm/mo ( 0.3 , 1.5 mm/mo ) ] and a larger head circumference at 12 mo [ difference : 0.19 cm ( 0.07 , 0.31 cm ) ] . A significant reduction in the incidence density of gastrointestinal infection was observed during the period from 3 to 6 mo in the 6-mo group [ adjusted incidence density ratio : 0.35 ( 0.13 , 0.96 ) ] , but no significant differences in risk of respiratory infectious outcomes or atopic eczema were apparent . CONCLUSIONS Exclusive breastfeeding for 6 mo is associated with a lower risk of gastrointestinal infection and no demonstrable adverse health effects in the first year of life The aim of this study was to assess the preventive effect of exclusive breast-feeding and early solid food avoidance on  atopic dermatitis ( AD ) in infancy . This study is part of a dietary clinical trial in a prospect i ve cohort of healthy term newborns at risk of atopy . It was recommended to breast-feed for at least 4 months and to avoid solid food in the same time-period . Eight hundred and sixty-five infants exclusively breast-fed , and 256 infants partially or exclusively formula-fed , were followed-up until the end of the first year following birth . AD and sensitization to milk and egg were considered as study end-points . The 1-year incidence of AD was compared between the two study groups . Adjusted odds ratios ( OR ) with 95 % confidence intervals ( CI ) were calculated by multiple logistic regression . The incidence of AD was calculated in relation to age at introduction of solid food and amount of food given . In the breast-fed group , the adjusted OR for AD was 0.47 ( 95 % CI 0.30 - 0.74 ) . The strongest risk factor was the occurrence of AD in the subject 's core family . The risk of infants with AD to be sensitized to milk was four times higher , and to egg eight times higher , than in infants without AD . Age at first introduction of solid food and diversity of solid food showed no effect on AD incidence . We conclude that in infants at atopic risk , exclusive breast-feeding for at least 4 months is effective in preventing AD in the first year of life PURPOSE To identify factors that might be targeted for intervention to increase breastfeeding among black mothers . DESIGN Secondary analysis of the 1988 National Maternal Infant Health Survey . PARTICIPANTS Black mothers ( N = 5,142 ) from a nationally representative sample of mothers who had births in 1988 . MAIN OUTCOME MEASURES Breastfeeding rates RESULTS Factors associated with breastfeeding included a mother 's plan to breastfeed ; Women , Infants and Children ( WIC ) advice , or advice from a prenatal-care provider on breastfeeding ;  and discussion of breastfeeding practice s at prenatal birth classes . CONCLUSIONS The results suggest that the prenatal period may be a critical time to influence a prospect i ve black mother 's decision to breastfeed her infant Abstract . One hundred and twenty‐one women with history of a previous child with atopic disease were r and omly allocated during the next pregnancy to antigen avoidance or control groups . Dietary advice consisted of almost complete exclusion of milk and dairy products , egg , fish , beef and peanut throughout pregnancy and lactation . A total of 109 completed the study . Maternal antigen avoidance was associated with reduced occurrence of atopic eczema and the skin involvement was less extensive and milder . The beneficial effect was observed mainly in the breast‐fed group . Among the fifty‐five who completed the trial of antigen avoidance , seventeen infants developed atopic eczema , five out of thirty‐five who were breast‐fed and twelve out of twenty who were formula‐fed . Among the offspring of fifty‐four control mothers given no dietary restriction , eczema was observed in twenty‐four infants , eleven out of thirty‐six breast‐fed and thirteen of eighteen formula‐fed . Avoidance of common dietary allergens during pregnancy and lactation enhanced the preventive beneficial effect of exclusive breast feeding on the incidence of atopic eczema among infants at high risk ABSTRACT A prospect i ve case‐control study is presented to assess an allergy prevention programme in children up to 36 months of age . Infants born at three maternity hospitals were followed from birth : 279 infants with high atopic risk ( intervention group ) were compared with 80 infants with similar atopic risk but no intervention ( non‐intervention group ) . The intervention programme included dietary measures ( exclusive and prolonged milk feeding diet followed by a hypoantigenic weaning diet ) and environmental measures ( avoidance of parental smoking in the presence of the babies , day care > 2 years of life ) . Mothers in this group who had insufficient breast milk were r and omly assigned to one of two coded formulas : either a hydrolysed milk formula ( Nidina HA , Nestlé ) or a conventional adapted formula ( Nan , Nestlé ) . Other environmental measures remained the same as for the breastfeeding mothers . The non‐intervention group were either breastfed or received the usual Italian milk feeding and weaning diet , without environmental advice . The main outcome measures were anthropometric measurements and allergic disease manifestations . Normal anthropometric data were observed both in the intervention group and in the nonintervention group . The incidence of allergic manifestations was much lower in the intervention group than in the nonintervention group at 1 year ( 11.5 versus 54.4 % , respectively ) and at 2 years ( 14.9 versus 65.6 % ) and 3 years ( 20.6 versus 74.1 % ) . Atopic dermatitis and recurrent wheezing were found in both the intervention group and the non‐intervention group from birth up to the second year of life , while urticaria and gastrointestinal disorders were only present in the non‐intervention group in the first year of life . Conjunctivitis and rhinitis were present after the second year in both the intervention group and the non‐intervention group . Relapse of the same allergic symptom was less in the intervention group ( 13.0 % ) than in the non‐intervention group ( 36.9 % ) . In comparison to the non‐intervention group , there were fewer intervention group cases with two or more different allergic symptoms ( 8.7 versus 32.6 % ) , and they were more likely to avoid steroid treatment ( 0 versus 10.8 % ) and hospital admission ( 0 versus 6.5 % ) . Babies in the non‐intervention group fed with adapted formula were more likely to develop allergies than breastfed babies in the same group . In the intervention group the breastfed infants had the lowest incidence of allergic symptoms , followed by the infants fed the hydrolysed formula ( ns ) . Infants in the intervention group fed the adapted formula had significantly more allergies than the breastfed and hydrolysed milk fed infants , although less than their counterparts in the non‐intervention group . Of the affected subjects in the intervention group , 80.4 % were RAST and /or Prick positive to food or inhalant allergens . Total serum IgE values detected at birth in the intervention group were not predictive , but at 1 and 2 years of age , IgE values more than 2 SD above the mean in asymptomatic babies were found to predictive for later allergy . In breastfed babies the total IgE level at 1 and 2 years of age was lower than in the other two feeding groups . Of the various factors tested in the non‐intervention group , the following were the most important in the pathogenesis of allergic symptoms : ( i ) formula implementation begun in the first week of life ; ( ii ) early weaning ( < 4 months ) ; ( iii ) feeding beef ( < 6 months ) ; ( iv ) early introduction of cow 's milk ( < 6 months ) ; and ( v ) parental smoking in the presence of the babies and early day care admission ( < 2 years of life ) . All the preventive measures used in this study ( exclusive breastfeeding and /or hydrolysed milk feeding , delayed and selective introduction of solid foods , and environmental advice ) were effective at the third year of follow‐up , greatly reducing allergic 
    Output:
    
There is no strong evidence of a protective effect of exclusive breastfeeding for at least 3 months against AD , even among children with a positive family history