A Single Meal of Milk Containing A2 Β-Casein Causes Fewer Symptoms and Lower Gas Production than Milk Containing Both A1 and A2 Β-Casein Among Lactose Intolerant Individuals

Abstract

Abstract Objectives We evaluated tolerance to single meals of milks containing different levels of a1 and a2 β-casein as compared to lactose-free milk. We also determined if lactose digestion was affected by a2, high a2 (Jersey) and high a1 (commercial) β-casein milks, as measured by breath hydrogen. Methods A double-blinded, randomized crossover trial was conducted in 21 verified lactose intolerant subjects, feeding four milks (commercial, Jersey, a2 and commercial lactose free) after an overnight fast. Breath hydrogen was measured, and intolerance symptoms were recorded for 6 hours following treatment. Results Mean hydrogen production and total symptoms were significantly lower following consumption of a2 milk as compared to commercial milk (P = 0.03 for both). Similarly, high a2 Jersey milk produced significantly lower hydrogen than commercial milk (P = 0.01). However, symptoms due to Jersey were not significantly different from commercial milk (P = 0.47). Conclusions A2 milk caused fewer symptoms and lower gas production in verified lactose intolerant subjects. Funding Sources Gift funds from the a2 Milk Company.