Research Article Low-Glycemic-Index Foods Can Decrease Systolic and Diastolic Blood Pressure in the Short Term Mina Hosseininasab, 1 Abdolreza Norouzy, 1 Mohsen Nematy, 1 and Shokoufeh Bonakdaran 2 1 Nutrition Research Center and Department of Nutrition, School of Medicine, Mashhad University of Medical Sciences, Mashhad 91779-48564, Iran 2 Endocrinology and Metabolism Center, Ghaem Hospital, Iran Correspondence should be addressed to Abdolreza Norouzy; norouzya@mums.ac.ir Received 7 January 2015; Accepted 17 February 2015 Academic Editor: Samy I. McFarlane Copyright © 2015 Mina Hosseininasab et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. We aimed to compare the efects of low- and high-GI foods on 24-hour ambulatory blood pressure. Methods. Tis longitudinal study was performed on 30 women, aged 18 to 40 years, during 24 hours. In the frst leg of study all recruited subjects were assigned to LGI period for 24 hours and, afer a 2-week washout period, all subjects were assigned to HGI period. BP was measured every hour during the 24-hour monitoring. Results. Afer the intervention, there were signifcant decreases in SBP and DBP in the LGI period (102.26±14.18 mmHg versus 112.86±9.33 mmHg for SBP and 66.96±10.39 mmHg versus 74.46±7.61 mmHg for DBP) ( = 0.00 and  = 0.002, resp.). However, in the HGI period, there was no signifcant change in SBP or DBP (110.66±9.85 versus 111.80 ± 9.57 for SBP and 71.16 ± 9.16 versus 74.26 ± 10.09 for DBP) ( = 0.6 and  = 0.06, resp.). Conclusion. Te results suggest that LGI foods may be benefcial in reducing 24-hour BP. 1. Introduction High blood pressure (BP) is defned as systolic BP (SBP) ≥ 140 mmHg and/or diastolic BP (DBP) ≥ 90 mmHg. High BP is an independent risk factor for cardiovascular diseases, stroke, and kidney diseases. It is also one of the most common health problems worldwide [1]. As previous studies indicate, several dietary factors such as increased salt intake, insufcient potassium, obesity, over- weight, excess alcohol intake, and high consumption of carbohydrates (CHO) including sugars and sof drinks can increase BP [2, 3]. However, total CHO intake has not been consistently associated with either increased or decreased BP. Diferences in the type and source of dietary CHO may have various impacts on the relationship between CHO intake and BP [4]. Prevention of elevated BP is an important public health issue with the aim of reducing the overall disease rate, caused by hypertension [1]. In fact, reduced BP could have signifcant impacts on cardiovascular diseases, morbidity, and mortality [5]. Glycemic index (GI) provides a numeric classifcation of CHO foods, based on their glycemic response that refects the rise in postprandial glycemia [6]. As previous studies have revealed, changes in SBP and DBP are associated with glycemic load (GL) and GI [3, 7, 8]. For instance, Philippou et al. in a study performed in 2009 found that a 6-month intensive lifestyle modifcation including dietary GI manipulation, in addition to healthy eating and weight loss, afects arterial compliance and 24-hour BP, which are risk factors for coronary heart disease (CHD). Low-GI (LGI) food has been suggested to be more efective in reducing CHD risks including pulse wave velocity and 24-hour BP [6]. However, previous studies have not considered factors such as obesity and family history of hypertension [3, 6, 8, 9]. Also, since participants difered from nonparticipants in terms of characteristics such as age, weight, height, ethnicity, and body mass index (BMI), the possibility of selection bias, which limits the generalization of the results, has not been ruled out. In the present study, we hypothesized that 24-hour LGI foods would signifcantly decrease 24-hour ambulatory BP. Hindawi Publishing Corporation International Journal of Hypertension Volume 2015, Article ID 801268, 5 pages http://dx.doi.org/10.1155/2015/801268