Unpasteurised milk: protective for allergies and asthma?

What is this study about?

Studies in farmers’ children have indicated that unpasteurised milk may protect against allergies and asthma. The reasons are unclear and these findings have not been confirmed in non-farmers.
The current study will assess these protective effects in the general population making use of a “natural experiment”. It will involve 300 non-farming families with children, where at least one family member regularly consumes unpasteurised milk
We will also recruit 150 families with children who have never consumed unpasteurised milk as a comparison group
The study will assess whether raw milk is associated with a lower prevalence of allergies and asthma and improved lung function. It will also study the immunological mechanisms and the involvement of pathogenic bacteria.
This study will contribute towards identifying the anti-allergic components within raw milk and has the potential to lead to innovative and safe interventions for allergies and asthma.

The aims of this study are to assess whether:

Consumption of raw milk is associated with a lower prevalence of allergies and asthma, lower levels of exhaled nitric oxide (NO; a measure of airway inflammation), and improved lung function.
The effects of raw milk show a dose-response relationship.
The effects of raw milk occur in both children and adults.
Consumption of raw milk affects T lymphocyte helper and regulatory function, allergen presenting cell response and innate immune responses.
Raw milk affects toll like receptor and CD14 expression (involved in recognition of bacterial components).
The (hypothesised) reduced risk of allergies and asthma is associated with the immune parameters described in aims 4 and 5.
Exposure to (raw milk-associated) pathogens is associated with atopy and asthma and the immune parameters described in aims 4 and 5.

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Brooks C, Pearce N, Douwes J. The hygiene hypothesis in allergy and asthma: an update. Curr Opin Allergy Clin Immunol, 2013; 13(1): 70-77.
Douwes J, Brooks C, van Dalen C, Pearce N. Importance of allergy in asthma: an epidemiologic perspective. Curr Allergy Asthma Rep, 2011; 11(5): 434-44.