Journal of Nutritional Science

  • Journal of Nutritional Science / Volume 2 / 2013, e43 (10 pages)
  • Copyright © The Author(s) 2013 The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution license <http://creativecommons.org/licenses/by/3.0/>.
  • DOI: http://dx.doi.org/10.1017/jns.2013.29 (About DOI), Published online: 02 January 2014

Human and Clinical Nutrition

Casein improves brachial and central aortic diastolic blood pressure in overweight adolescents: a randomised, controlled trial

Karina Arnberga1 c1, Anni Larnkjæra1, Kim F. Michaelsena1, Signe Marie Jensena1, Camilla Hoppea2 and Christian Mølgaarda1

a1 Department of Nutrition, Exercise and Sports, University of Copenhagen, Rolighedsvej 30, 1958 Frederiksberg, Denmark

a2 The National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark

Abstract

Arterial stiffness, blood pressure (BP) and blood lipids may be improved by milk in adults and the effects may be mediated via proteins. However, limited is known about the effects of milk proteins on central aortic BP and no studies have examined the effects in children. Therefore, the present trial examined the effect of milk and milk proteins on brachial and central aortic BP, blood lipids, inflammation and arterial stiffness in overweight adolescents. A randomised controlled trial was conducted in 193 overweight adolescents aged 12–15 years. They were randomly assigned to drink 1 litre of water, skimmed milk, whey or casein for 12 weeks. The milk-based test drinks contained 35 g protein/l. The effects were compared with the water group and a pretest control group consisting of thirty-two of the adolescents followed 12 weeks before the start of the intervention. Outcomes were brachial and central aortic BP, pulse wave velocity and augmentation index, serum C-reactive protein and blood lipids. Brachial and central aortic diastolic BP (DBP) decreased by 2·7% (P = 0·036) and 2·6 % (P = 0·048), respectively, within the casein group and the changes were significantly different from those of the pretest control group (P = 0·040 and P = 0·034, respectively). There was a significant increase in central aortic DBP, and in brachial and central systolic BP in the whey group compared with the water group (P = 0·003, P = 0·009 and P = 0·002, respectively). There were no changes in measures of arterial stiffness or blood lipid concentrations. A high intake of casein improves DBP in overweight adolescents. Thus, casein may be beneficial for younger overweight subjects in terms of reducing the long-term risk of CVD. In contrast, whey protein seems to increase BP compared with drinking water; however, water may be considered an active control group.

(Received February 27 2013)

(Revised September 13 2013)

(Accepted September 16 2013)

Key words

  • Whey;
  • Casein;
  • Overweight children: Blood pressure

Abbreviations

  • ACE:angiotensin-I-converting enzyme;
  • Aix:augmentation index;
  • BP:blood pressure;
  • CRP:C-reactive protein;
  • DBP:diastolic blood pressure;
  • PWV:pulse wave velocity;
  • SBP:systolic blood pressure

Correspondence

c1 Corresponding author: Karina Arnberg, fax +45 3533 2483, email karnberg@hotmail.com

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