Hjerte- og karsykdommer
(Ischaemic heart disease)
J Appl Genet. 2007;48(3):189-98.Links
Polymorphism of bovine beta-casein and its potential effect on human health.
Kamiński S, Cieslińska A, Kostyra E.
Department of Animal Genetics, University of Warmia and Mazury, M. Oczapowskiego 5, 10-718 Olsztyn, Poland. Denne e-postadressen er beskyttet mot programmer som samler e-postadresser. Du må aktivere javaskript for å kunne se den.
Proteins in bovine milk are a common source of bioactive peptides. The peptides are released by the digestion of caseins and whey proteins. In vitro the bioactive peptide beta-casomorphin 7 (BCM-7) is yielded by the successive gastrointestinal proteolytic digestion of bovine beta-casein variants A1 and B, but this was not seen in variant A2. In hydrolysed milk with variant A1 of beta-casein, BCM-7 level is 4-fold higher than in A2 milk. Variants A1 and A2 of beta-casein are common among many dairy cattle breeds. A1 is the most frequent in Holstein-Friesian (0.310-0.660), Ayrshire (0.432-0.720) and Red (0.710) cattle. In contrast, a high frequency of A2 is observed in Guernsey (0.880-0.970) and Jersey (0.490-0.721) cattle. BCM-7 may play a role in the aetiology of human diseases. Epidemiological evidence from New Zealand claims that consumption of beta-casein A1 is associated with higher national mortality rates from ischaemic heart disease. It seems that the populations that consume milk containing high levels of beta-casein A2 have a lower incidence of cardiovascular disease and type 1 diabetes. BCM-7 has also been suggested as a possible cause of sudden infant death syndrome. In addition, neurological disorders, such as autism and schizophrenia, seem to be associated with milk consumption and a higher level of BCM-7. Therefore, careful attention should be paid to that protein polymorphism, and deeper research is needed to verify the range and nature of its interactions with the human gastrointestinal tract and whole organism.
PMID: 17666771 [PubMed - indexed for MEDLINE]
Ischaemic heart disease, Type 1 diabetes, and cow milk A1 beta-casein.
Laugesen M, Elliott R.
Health New Zealand, Auckland, New Zealand. Denne e-postadressen er beskyttet mot programmer som samler e-postadresser. Du må aktivere javaskript for å kunne se den.
AIM: To test the correlation of per capita A1 beta-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 beta-casein content (A1/beta) (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/beta in milk and cream (r = 0.47, p <0.05). Correlations were not significant for A2, B or C variants of milk beta-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 beta-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 beta-casein/capita. Surveys of A1 beta-casein consumption in two-year-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.
PMID: 12601419 [PubMed - indexed for MEDLINE]
Med Hypotheses. 2001 Feb;56(2):262-72.Links
beta-casein A1, ischaemic heart disease mortality, and other illnesses.
A2 Corporation Ltd, 29 Summer Street, Devonport, Auckland, New Zealand. Denne e-postadressen er beskyttet mot programmer som samler e-postadresser. Du må aktivere javaskript for å kunne se den.
The risk factors identified with cardiovascular disease studied in the WHO MONICA project have been shown to have a limited relationship with the coronary heart disease mortality rates between centres, and in mirroring the historical rise and decline in deaths from the disease. Here we show that correlation of the calculated consumption of the milk protein, beta-casein A1 (excluding milk protein in cheese) against ischaemic heart disease (IHD) mortality has a r2 = 0.86. In the states of the former West Germany, where the breed composition of regional cattle herds has remained virtually constant since the 1950s, IHD mortality by state correlates with the estimated consumption of beta-casein A1. Information on other recognized dietary risk factors does not indicate any significant regional difference. Similarly, the populations of Toulouse in France and Belfast in Northern Ireland have almost identical collective 'traditional' risk factors for heart disease, yet the respective mortality rates vary more than threefold. People from Northern Ireland are estimated to consume 3.23 times more beta-casein A1, excluding cheese, than the French. The remarkable agreement between mortality and the consumption of this allele suggests that this factor is worthy of serious consideration as a potential source of cardiovascular disease when taken in conjunction with regional variations in the traditional risk factors. beta-casein A1 consumption also correlates strongly with type 1 diabetes incidence in 0-14-year-olds, suggesting that IHD and diabetes may share at least one causative risk factor.
PMID: 11425301 [PubMed - indexed for MEDLINE]