Brick T , Schober Y , Bocking C , Pekkanen J , Genuneit J , Loss G , Dalphin JC , Riedler J , Lauener R , Nockher WA , Renz H , Vaarala O , Braun-Fahrlander C , von Mutius E , Ege MJ , Pfefferle PI , Pasture study group. - 47518 N - J Allergy Clin Immunol 2016 ; in press.

Omega-3 fatty acids contribute to the asthma-protective effect of unprocessed cow's milk

BACKGROUND: Living on a farm has repeatedly been shown to protect children from asthma and allergies. A major factor involved in this effect is consumption of unprocessed cow’s milk obtained directly from a farm. However, this phenomenon has never been shown in a longitudinal design, and the responsible milk components are still unknown.
OBJECTIVES: We sought to assess the asthma-protective effect of unprocessed cow’s milk consumption in a birth cohort and to determine whether the differences in the fatty acid (FA) composition of unprocessed farm milk and industrially processed milk contributed to this effect.
METHODS: The Protection Against Allergy-Study in Rural Environments (PASTURE) study followed 1133 children living in rural areas in 5 European countries from birth to age 6 years. In 934 children milk consumption was assessed by using yearly questionnaires, and samples of the “usually” consumed milk and serum samples of the children were collected at age 4 years. Doctor-diagnosed asthma was parent reported at age 6 years. In a nested case-control study of 35 asthmatic and 49 nonasthmatic children, 42 FAs were quantified in milk samples.
RESULTS: The risk of asthma at 6 years of age was reduced by previous consumption of unprocessed farm milk compared with shop milk (adjusted odds ratio for consumption at 4 years, 0.26; 95% CI, 0.10-0.67). Part of the effect was explained by the higher fat content of farm milk, particularly the higher levels of omega-3 polyunsaturated FAs (adjusted odds ratio, 0.29; 95% CI, 0.11-0.81).
CONCLUSION: Continuous farm milk consumption in childhood protects against asthma at school age partially by means of higher intake of omega-3 polyunsaturated FAs, which are precursors of anti-inflammatory mediators.