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A casein variant in cow's milk is atherogenic
Tailford, K. A., Berry, C. L., Thomas, A. C. and Campbell, J. H. (2003) A casein variant in cow's milk is atherogenic. Atherosclerosis, 170 1: 13-19.
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| Author(s) |
Tailford, K. A. Berry, C. L. Thomas, A. C. Campbell, J. H.
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| Title |
A casein variant in cow's milk is atherogenic
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| Journal name |
Atherosclerosis
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| Publication date |
2003
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| Volume number |
170
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| Issue number |
1
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| ISSN |
0021-9150
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| Start page |
13
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| End page |
19
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| Total pages |
7
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| Place of publication |
Clare
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| Publisher |
Elsevier Sci Ireland
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| Collection year |
2003
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| Language |
eng
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| Subject |
C1 270000 Biological Sciences 730106 Cardiovascular system and diseases
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| Abstract |
Casein is a major protein in cow's milk that occurs in several variant forms, two of which are beta-casein A(1) and beta-casein A(2). The levels of these two proteins vary considerably in milk dependent on the breed of cow, and epidemiology studies suggest that there is a relationship between their consumption and the degree of atherosclerosis. In the present study, the direct effect of consumption of beta-casein A(1) vs beta-casein A(2) on atherosclerosis development was examined in a rabbit model. Sixty rabbits had their right carotid artery balloon de-endothelialised at t = 0, divided randomly into 10 groups (n = 6 per group), then for 6 weeks fed a diet containing 0, 5, 10 or 20% casein isolate, either beta-casein variant A(1) or A(2) made up to 20% milk protein with whey. Some groups had their diets supplemented with 0.5% cholesterol. Blood samples were collected at t = 0, 3 and 6 weeks and rabbits were sacrificed at t = 6 weeks. In the absence of dietary cholesterol, beta-casein A(1) produced significantly higher (P < 0.05) serum cholesterol, LDL, HDL and triglyceride levels than whey diet alone, which in turn produced higher levels than beta-casein A(2). Rabbits fed beta-casein A(1) had a higher percent surface area of aorta covered by fatty streaks than those fed beta-casein A(2) (5.2+/-0.81 vs 1.1+/-0.39, P < 0.05) and the thickness of the fatty streak lesions in the aortic arch was significantly higher (0.04+/-0.010 vs 0.00, P < 0.05). Similarly, the intima to media ratio (I:M) of the balloon injured carotid arteries in A(1) fed animals (0.77+/-0.07) was higher than in those that consumed A(2) (0.57+/-0.04) or whey (0.58+/-0.04), but this did not reach significance. In the presence of 0.5% dietary cholesterol, the thickness of the aortic arch lesions was higher (P < 0.05) in 5, 10 and 20% casein A(1) fed animals compared with their A(2) counterparts, while other parameters were not significantly different. It is concluded that beta-casein A(1) is atherogenic compared with beta-casein A(2). (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.
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| Keyword(s) |
Peripheral Vascular Disease beta-casein A(1) beta-casein A(2) atherosclerosis cow milk fatty streaks Bovine Beta-casein Atherosclerotic Lesions Induced Hypercholesterolemia Genetic-variants Heart-disease Proteins Polymorphism Casomorphin Mortality Rabbits
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