Dietary calcium and dairy products modulate oxidative and inflammatory stress in mice and humans.
We have recently shown 1alpha,25-dihydroxycholecalciferol increased oxidative stress and inflammatory stress in vitro, whereas suppression of 1alpha,25-dihydroxycholecalciferol with dietary calcium (Ca) decreased oxidative and inflammatory stress in vivo. However, dairy products contains additional factors, such as angiotensin-converting enzyme inhibitors, which may further suppress oxidative and inflammatory stress. Accordingly, this study was designed to study the effects of the short-term (3 wk) basal suboptimal Ca (0.4%), high-Ca (1.2% from CaCO(3)), and high-dairy (1.2% Ca from milk) obesigenic diets on oxidative and inflammatory stress in adipocyte fatty acid-binding protein-agouti transgenic mice. Adipose tissue reactive oxygen species (ROS) production and NADPH oxidase mRNA and plasma malondialdehyde (MDA) were reduced by the high-Ca diet (P < 0.001) compared with the basal diet and ROS and MDA were further decreased by the high-dairy diet (P < 0.001). The high-Ca and -dairy diets also resulted in suppression of adipose tissue tumor necrosis factor alpha and interleukin (IL)-6 mRNA (P = 0.001) compared with the basal diet, whereas an inverse pattern was noted for adiponectin and IL-15 mRNA (P = 0.002). Consequently, we conducted a follow-up evaluation of adiponectin and C-reactive protein (CRP) in archival samples from 2 previous clinical trials conducted in obese men and women. Twenty-four weeks of feeding a high-dairy eucaloric diet and hypocaloric diet resulted in an 11 (P < 0.03) and 29% (P < 0.01) decrease in CRP, respectively (post-test vs. pre-test), whereas there was no significant change in the low-dairy groups. Adiponectin decreased by 8% in subjects fed the eucaloric high-dairy diet (P = 0.003) and 18% in those fed the hypocaloric high-dairy diet (P < 0.05). These data demonstrate that dietary Ca suppresses adipose tissue oxidative and inflammatory stress.
Zemel
Michael B
MB
Department of Nutrition, University of Tennessee, Knoxville, TN 37996, USA. mzemel@utk.edu
Sun
Xiaocun
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D052242:Adiponectin / Q000097:blood / Q000378:metabolism; D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism; D002136:Calcium, Dietary / Q000494:pharmacology*; D003611:Dairy Products; D004032:Diet; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D006801:Humans; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008892:Milk; D009747:Nutritional Physiological Phenomena; D009765:Obesity; D018384:Oxidative Stress / Q000187:drug effects*; D011897:Random Allocation
D052242:Adiponectin; D002136:Calcium, Dietary; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002097:C-Reactive Protein