In this study, we hypothesized that replacing conventional milk, which contains A1 and A2 β-casein (A1 milk), with milk that contains only A2 β-casein (A2 milk) in the diet of dairy or milk-intolerant preschoolers would result in reduced gastrointestinal symptoms associated with milk intolerance, and that this would correspond with cognitive improvements.
This randomized, double-blind, crossover study aimed to compare the effects of 5 days’ consumption of conventional milk versus A2 milk on gastrointestinal symptoms, as assessed via visual analog scales, average stool frequency and consistency, and serum inflammatory and immune biomarkers in healthy preschoolers with mild-to-moderate milk intolerance. The study also aimed to compare changes in the cognitive behavior of preschoolers, based on Subtle Cognitive Impairment Test scores.
Subjects who consumed A2 milk had significantly less severe gastrointestinal symptoms as measured by visual analog scales, reduced stool frequency, and improvements in stool consistency, compared with subjects consuming conventional milk. There were significant increases from baseline in serum interleukin-4, immunoglobulins G, E, and G1, and beta-casomorphin-7 coupled to lower glutathione levels, in subjects consuming conventional rather than A2 milk. Subtle Cognitive Impairment Test analysis showed significant improvements in test accuracy after consumption of A2 milk. There were no severe adverse events related to consumption of either milk product.
Replacing conventional milk with A2 milk reduced gastrointestinal symptoms associated with milk intolerance in Chinese preschool children, with corresponding improvements in aspects of cognitive performance.
*Department of Child and Adolescent Health Care, Xin-Hua Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai
†Department of Pediatric Gastroenterology, Peking University Third Hospital, Peking University Third Hospital, Beijing
‡S.P.R.I.M. China (Shanghai) Consulting Co., Ltd., Shanghai, China
§School of Health Sciences, RMIT University, Bundoora
||Department of Gastroenterology, Central Clinical School, Monash University, Victoria, Australia.
Address correspondence and reprint requests to Sheng Xiaoyang, MD, PhD, Departmental and Behavioral Pediatric Department and Child Primary Care Department, MOE-Shanghai Key Lab for Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (e-mail: email@example.com).
Received 25 February, 2019
Accepted 21 June, 2019
Supplemental digital content is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML text of this article on the journal's Web site (www.jpgn.org).
https://clinicaltrials.gov/ct2/show/NCT03081845 registration number: NCT03081845.
The a2 Milk Company provided funding for the study and had insight into drafting the manuscript, but the authors had full responsibility for, and decided about, manuscript content.
Dr Yelland is co-director of NeuroTest Pty Ltd, the company that owns and distributes the Subtle Cognitive Impairment Test. The other authors report no conflicts of interest.
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