Laugesen, M.Elliott, R.B.2009-08-192009-08-192003New Zealand Medical Journal 116 (1168), 20031175-8716eid=2-s2.0-0141713649http://hdl.handle.net/2292/4746An open access copy of this article is available and complies with the copyright holder/publisher conditions.Aim To test the correlation of per capita A1 ß-casein (A1/capita) and milk protein with: 1) ischaemic heart disease (IHD) mortality; 2) Type 1 (insulin-dependent) diabetes mellitus (DM-1) incidence. Methods A1/capita was estimated as the product of per capita cow milk and cream supply and its A1 ß-casein content (A1/ ß) (calculated from herd tests and breed distribution, or from tests of commercial milk), then tested for correlation with: 1) IHD five years later in 1980, 1985, 1990 and 1995, in 20 countries which spent at least US $1000 (purchasing power parities) per capita in 1995 on healthcare; 2) DM-1 at age 0–14 years in 1990–4 (51 were surveyed by WHO DiaMond Project; 19 had A1 data). For comparison, we also correlated 77 food, and 110 nutritive supply FAO (Food and Agriculture Organization)-based measures, against IHD and DM-1. Results For IHD, cow milk proteins (A1/capita, r = 0.76 , p <0.001; A1/capita including cheese, r = 0.66; milk protein r = 0.60, p = 0.005) had stronger positive correlations with IHD five years later, than fat supply variables, such as the atherogenic index (r = 0.50), and myristic, the 14-carbon saturated fat (r = 0.48, p <0.05). The Hegsted scores for estimating serum cholesterol (r = 0.42); saturated fat (r = 0.37); and total dairy fat (r = 0.31) were not significant for IHD in 1995. Across the 20 countries, a 1% change in A1/capita in 1990 was associated with a 0.57% change in IHD in 1995. A1/capita correlations were stronger for male than female mortality. On multiple regression of A1/capita and other food supply variables in 1990, only A1/capita was significantly correlated with IHD in 1995. DM-1 was correlated with supply of: A1/capita in milk and cream (r = 0.92, p <0.00001); milk and cream protein excluding cheese (r = 0.68, p <0.0001); and with A1/ß in milk and cream (r = 0.47, p <0.05). Correlations were not significant for A2, B or C variants of milk b-casein. DM-1 incidence at 0–4, 5–9 and 10–14 years was equally correlated (r = 0.80, 0.81, 0.81 respectively) with milk protein supply. A 1% change in A1/capita was associated with a 1.3% change in DM-1 in the same direction. Conclusions Cow A1 ß-casein per capita supply in milk and cream (A1/capita) was significantly and positively correlated with IHD in 20 affluent countries five years later over a 20-year period – providing an alternative hypothesis to explain the high IHD mortality rates in northern compared to southern Europe. For DM-1, this study confirms Elliott’s 1999 correlation on 10 countries for A1/capita,1 but not for B ß-casein/capita. Surveys of A1 b-casein consumption in twoyear- old Nordic children, and some casein animal feeding experiments, confirm the A1/capita and milk protein/capita correlations. They raise the possibility that intensive dairy cattle breeding may have emphasised a genetic variant in milk with adverse effects in humans. Further animal research and clinical trials would be needed to compare disease risks of A1-free versus ‘ordinary’ milk.Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from http://www.sherpa.ac.uk/romeo/issn/0028-8446/https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmJournal ArticleFields of Research::320000 Medical and Health SciencesCopyright: New Zealand Medical Association (NZMA)12601419http://purl.org/eprint/accessRights/OpenAccess