Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study
Background/objectives:At present, there is debate about the gastrointestinal effects of A1-type beta-casein protein in cows' milk compared with the progenitor A2 type. In vitro and animal studies suggest that digestion of A1 but not A2 beta-casein affects gastrointestinal motility and inflammat...
| Main Authors: | , , , |
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| Format: | Journal Article |
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Nature Publishing Group
2014
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| Online Access: | http://hdl.handle.net/20.500.11937/62832 |
| _version_ | 1848760923572928512 |
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| author | Ho, S. Woodford, K. Kukuljan, S. Pal, Sebely |
| author_facet | Ho, S. Woodford, K. Kukuljan, S. Pal, Sebely |
| author_sort | Ho, S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Background/objectives:At present, there is debate about the gastrointestinal effects of A1-type beta-casein protein in cows' milk compared with the progenitor A2 type. In vitro and animal studies suggest that digestion of A1 but not A2 beta-casein affects gastrointestinal motility and inflammation through the release of beta-casomorphin-7. We aimed to evaluate differences in gastrointestinal effects in a human adult population between milk containing A1 versus A2 beta-casein.Subjects/methods:Forty-one females and males were recruited into this double-blinded, randomised 8-week cross-over study. Participants underwent a 2-week dairy washout (rice milk replaced dairy), followed by 2 weeks of milk (750 ml/day) that contained beta-casein of either A1 or A2 type before undergoing a second washout followed by a final 2 weeks of the alternative A1 or A2 type milk.Results:The A1 beta-casein milk led to significantly higher stool consistency values (Bristol Stool Scale) compared with the A2 beta-casein milk. There was also a significant positive association between abdominal pain and stool consistency on the A1 diet (r=0.520, P=0.001), but not the A2 diet (r=-0.13, P=0.43). The difference between these two correlations (0.52 versus -0.13) was highly significant (P<0.001). Furthermore, some individuals may be susceptible to A1 beta-casein, as evidenced by higher faecal calprotectin values and associated intolerance measures.Conclusions:These preliminary results suggest differences in gastrointestinal responses in some adult humans consuming milk containing beta-casein of either the A1 or the A2 beta-casein type, but require confirmation in a larger study of participants with perceived intolerance to ordinary A1 beta-casein-containing milk.European Journal of Clinical Nutrition advance online publication, 2 July 2014; doi:10.1038/ejcn.2014.127. |
| first_indexed | 2025-11-14T10:23:29Z |
| format | Journal Article |
| id | curtin-20.500.11937-62832 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:23:29Z |
| publishDate | 2014 |
| publisher | Nature Publishing Group |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-628322019-05-22T06:07:13Z Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study Ho, S. Woodford, K. Kukuljan, S. Pal, Sebely Background/objectives:At present, there is debate about the gastrointestinal effects of A1-type beta-casein protein in cows' milk compared with the progenitor A2 type. In vitro and animal studies suggest that digestion of A1 but not A2 beta-casein affects gastrointestinal motility and inflammation through the release of beta-casomorphin-7. We aimed to evaluate differences in gastrointestinal effects in a human adult population between milk containing A1 versus A2 beta-casein.Subjects/methods:Forty-one females and males were recruited into this double-blinded, randomised 8-week cross-over study. Participants underwent a 2-week dairy washout (rice milk replaced dairy), followed by 2 weeks of milk (750 ml/day) that contained beta-casein of either A1 or A2 type before undergoing a second washout followed by a final 2 weeks of the alternative A1 or A2 type milk.Results:The A1 beta-casein milk led to significantly higher stool consistency values (Bristol Stool Scale) compared with the A2 beta-casein milk. There was also a significant positive association between abdominal pain and stool consistency on the A1 diet (r=0.520, P=0.001), but not the A2 diet (r=-0.13, P=0.43). The difference between these two correlations (0.52 versus -0.13) was highly significant (P<0.001). Furthermore, some individuals may be susceptible to A1 beta-casein, as evidenced by higher faecal calprotectin values and associated intolerance measures.Conclusions:These preliminary results suggest differences in gastrointestinal responses in some adult humans consuming milk containing beta-casein of either the A1 or the A2 beta-casein type, but require confirmation in a larger study of participants with perceived intolerance to ordinary A1 beta-casein-containing milk.European Journal of Clinical Nutrition advance online publication, 2 July 2014; doi:10.1038/ejcn.2014.127. 2014 Journal Article http://hdl.handle.net/20.500.11937/62832 10.1038/ejcn.2014.127 Nature Publishing Group restricted |
| spellingShingle | Ho, S. Woodford, K. Kukuljan, S. Pal, Sebely Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title | Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title_full | Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title_fullStr | Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title_full_unstemmed | Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title_short | Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| title_sort | comparative effects of a1 versus a2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study |
| url | http://hdl.handle.net/20.500.11937/62832 |