Review Article Dairy product consumption and the metabolic syndrome Marzieh Abedini a , Ebrahim Falahi b , Sajjad Roosta a, * a Nutrition Department, Faculty of Health and Nutrition, Lorestan University of Medical Sciences, Khorramabad, Iran b Nutrition Health Research Center, Faculty of Health and Nutrition, Lorestan University of Medical Sciences, Khorramabad, Iran 1. Introduction Cardiovascular diseases (CVDs) are one of the main causes of mortality in Iran [1], and the prevalence of these disorders continues to rise [2]. Persons with the metabolic syndrome (MetS) are at greater risk of CVD [3]. The prevalence of metabolic syndrome has been increasing throughout the world. According to the National Health and Nutritional Examination Survey (NHANES) [4], the prevalence of metabolic syndrome among adults in the United States was approximately 23% from 1988 to 1994, but increased to almost 34% from 2003 to 2006 even though the criterion for fasting blood glucose was updated to 100 mg/dl [5]. Metabolic syndrome was defined as the presence of 3 of the following 5 components as recommended by the Adult Treatment Panel III [6]: (1) enlarged waist circumference (waist circumfer- ence more than 102 cm in men and 88 cm in women); (2) low serum HDL cholesterol (less than 40 mg/dl in men and 50 mg/dl in women); (3) high serum triacylglycerol concentrations (more than 150 mg/dl); (4) elevated blood pressure (more than 130/ 85 mmHg); and (5) abnormal glucose homeostasis (fasting plasma glucose concentration more than 110 mg/dl). However, it is well established that both energy restriction and dietary composition play an important role in this respect. More specifically, several studies have suggested that dairy food products have a positive impact on the prevention of the metabolic syndrome. The aim of the present review is now to briefly summarize findings from epidemiological studies on the relationship between dairy product consumption and the metabolic syndrome and to discuss the results from intervention studies on the effects of dairy products and dairy constituents on features of this syndrome. We focused on studies carried out during the last decade. 2. Methods A search for relevant literature was undertaken on Web of Science, Google scholar, Pubmed (2000 to July 2013), to identify observational studies which examined the association between dairy intake and metabolic syndrome (prevalence or incidence), and for any randomized controlled trials investigating the effect of dairy intake on MetS. Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2014) xxx–xxx A R T I C L E I N F O Keywords: Dairy products Dairy consumption Yogurt Metabolic syndrome Cardiovascular risk factors A B S T R A C T Aims: To briefly summarize findings from epidemiological studies on the relationship between dairy product consumption and the metabolic syndrome(MetS). Materials and methods: A search for relevant literature was undertaken on Web of Science, Google scholar, Pubmed (2000 to July 2013), to identify observational studies which examined the association between dairy intake and MetS (prevalence or incidence), and for any randomized controlled trials investigating the effect of dairy intake on MetS. Results: Here we review the physiological effects and possible mechanisms involved of three main dairy constituents (calcium (Ca), protein, fat) on important components of the MetS. Effects of Ca may be related to intestinal binding to fatty acids or bile acids, or to changes in intracellular Ca metabolism by suppressing calciotropic hormones. Dietary proteins may increase satiety in both the short and longer term, which may result in a reduced energy intake. Dairy proteins are precursors of angiotensin-I converting enzyme-inhibitory peptides, which may lower blood pressure. To reduce the intake of saturated fatty acids (SFA), the consumption of low-fat instead of high-fat dairy products is recommended. Conclusion: More research is warranted to better understand the physiological effects and the mechanisms involved of dairy products in the prevention and treatment of the MetS. ß 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +98 6614209972; fax: +98 6614209974. E-mail address: sajjad.roosta@yahoo.com (S. Roosta). G Model DSX-404; No. of Pages 4 Please cite this article in press as: Abedini M, et al. Dairy product consumption and the metabolic syndrome. Diab Met Syndr: Clin Res Rev (2014), http://dx.doi.org/10.1016/j.dsx.2014.04.027 Contents lists available at ScienceDirect Diabetes & Metabolic Syndrome: Clinical Research & Reviews jo ur n al h o mep ag e: www .elsevier .c om /loc ate/d s x http://dx.doi.org/10.1016/j.dsx.2014.04.027 1871-4021/ß 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved.