Researchers in Italy have shown that beta-lactoglobulin, one of the key allergens in cow’s milk, can be modified via its vitamin A related component retinoic acid. Once modified, the beta-lactoglobulin appears to have reduced allergic potential.
Beta-lactoglobulin is part of a family of proteins known as the lipocalins. This protein family is characterized by molecular pockets that can take in small molecules like retinoic acid, which is a metabolite of vitamin A.
The recent study showed that when the molecular pockets of beta-lactoglobulin are not loaded, the protein can initiate an allergic response. When loaded with retinoic acid, the immune response is moderated.
The authors suggest feeding vitamin A to milk-producing cows could ensure loading of beta-lactoglobulin with retinoic acid, thereby making the milk of these cows less likely to invoke the development of allergy to this specific component of cow’s milk. Their studies indicate there would be no change to the allergenicity of the milk for those who have already developed allergy to beta-lactoglobulin.
Further studies are needed to determine whether a similar response could be achieved through dietary supplements.
Modern diary processing techniques include the removal of natural hydrophobic compounds including retinoic acid during defatting processes. While these are later supplemented, the precise loading of retinoic acid into the metabolic pocket seems to be critical to the allergic potential of beta-lactoglobulin, and this may also be an area for future focus.
Reference: Hufnagi et al. Scientific Reports Vol 8, Article number 1598.
Available via Open Access.
Additional reporting from Science Daily