The protective effect of farm milk consumption on childhood asthma and atopy: the GABRIELA study.
Level 4 - case-series / case-control
Cross-sectional survey and nested biomarker analysis
PubMed 21875744 · doi:10.1016/j.jaci.2011.07.048
What was done
Parents of 8,334 school-aged children across rural Germany, Austria, and Switzerland completed questionnaires on farm milk consumption and other farm exposures. Serum specific IgE was measured in 7,606 children. Viable bacterial counts, whey protein levels, and total fat content were analyzed in 800 home-collected cow's milk samples. Multiple regression analyses examined associations between reported milk consumption, measured milk constituents, and asthma, atopy, and hay fever.
What was found
Reported raw milk consumption was inversely associated with asthma (adjusted odds ratio [aOR] 0.59; 95% CI, 0.46-0.74), atopy (aOR 0.74; 95% CI, 0.61-0.90), and hay fever (aOR 0.51; 95% CI, 0.37-0.69) independent of other farm exposures. Boiled farm milk showed no protective association. Viable bacterial counts and total fat content showed no significant association with asthma or atopy. Higher levels of specific whey proteins were inversely associated with asthma but not atopy: bovine serum albumin (highest vs. lowest level aOR 0.53; 95% CI, 0.30-0.97), α-lactalbumin (per interquartile range aOR 0.71; 95% CI, 0.52-0.97), and β-lactoglobulin (per interquartile range aOR 0.62; 95% CI, 0.39-0.97).
Why it matters
This study links the protective effect of raw milk against childhood asthma specifically to whey protein fractions rather than milk fat or viable bacterial load.
Limits
The cross-sectional design cannot establish causality. Objective milk constituent measurements were available in only 800 of the 8,334 participants. Milk exposure was parent-reported, introducing potential recall and reporting bias, and infectious risks of raw milk consumption were not assessed.
Cited by
- supports Data indicates that children who consume whole or raw milk have a significant reduction in allergies and atopy.