UNSALTED TOMATO JUICE LOWERS HEART RISK
Food Science
ORIGINAL RESEARCH Open Access
Unsalted tomato juice intake improves blood pressure and serum low‐density lipoprotein cholesterol level in local Japanese residents at risk of cardiovascular disease
Abstract
The aim of this study was to investigate the effects of unsalted tomato juice intake on cardiovascular risk markers in local Japanese residents. Four hundred and eighty‐one local residents in Kuriyama, Japan, were enrolled in this study. Throughout the year of the study, they were provided with as much unsalted tomato juice as they wanted. Participants were screened for cardiovascular risk markers, such as blood pressure (BP), serum lipid profile, and glucose tolerance, before and after the study period. Of the study participants, 260 participated in a detailed study of their lifestyle factors. The average ages of the 184 male and 297 female participants were 56.3 ± 13.3 (mean ± SD) and 58.4 ± 11.7 years, respectively. BP in 94 participants with untreated prehypertension or hypertension was significantly lowered (systolic BP, 141.2 ± 12.1–137.0 ± 16.3 mmHg, p = 0.003; diastolic BP, 83.3 ± 10.1–80.9 ± 11.1 mmHg, p = 0.012, paired t test). Further, the serum low‐density lipoprotein cholesterol (LDL‐C) level in 125 participants with untreated dyslipidemia significantly decreased (155.0 ± 23.2–149.9 ± 25.0 mg/dl, p = 0.005, paired t test). These beneficial effects were not different between sexes and among the different age groups. No significant difference in lifestyle was found before and after the study. Unsalted tomato juice intake improved systolic and diastolic BP and serum LDL‐C level in local Japanese residents at risk of cardiovascular conditions.
1 INTRODUCTION
Cardiovascular diseases (CVDs) are the biggest causes of mortality worldwide, and according to the World Health Organization (WHO), they were responsible for 15.2 million global deaths (26.7%) in 2016 (retrieved from http://www.who.int/mediacentre..../factsheets/fs310/en Even when CVDs are not fatal, they often result in permanent damage to critical organs, which in turn causes activity restriction, nursing care, and reduced life expectancy. The main pathophysiological cause of CVDs is atherosclerosis, which is a chronic inflammatory reaction that begins as a response to injury of the arterial intima (Ross, 1999). This type of endothelial injury is induced by several factors, such as endotoxins, viruses, homocysteine, and cigarette smoke (Widlansky, Gokce, Keaney, & Vita, 2003). Chronic endothelial injury in hypertension, dyslipidemia, and diabetes are also important contributors of atherosclerosis progression (National Heart, Lung, & Blood Institute, 2013 retrieved from https://www.nhlbi.nih.gov/heal....th-topics/assessing- Beckman, Creager, & Libby, 2002; Libby, Aikawa, & Schönbeck, 2000; Sander, Kukla, Klingelhöfer, Winbeck, & Conrad, 200. Therefore, it is crucial to regulate blood pressure (BP), and lipid and glucose metabolism, to prevent the development of CVDs.
Tomato contains a variety of bioactive compounds, such as carotenoid, vitamin A, calcium, and gamma‐aminobutyric acid, which may play a role in maintaining physical and psychological health, including the prevention of CVD (Hak et al., 2004; Yanai et al., 2017; Zorumski, Paul, Izumi, Covey, & Mennerick, 2013). For example, the intake of lycopene, a carotenoid rich in tomatoes and known to have strong antioxidant activity (Oshima, Ojima, Sakamoto, Ishiguro, & Terao, 1996), has been reported to be inversely associated with the risk of CVDs (Agarwal & Rao, 2000; Hak et al., 2004; Rissanen et al., 2001); the mechanism underlying this effect may be an improvement in the serum lipid profile (Ried & Falker, 2011; Sesso, Wang, Ridker, & Buring, 2012; Yanai et al., 2017). There are also reports about the beneficial effects of lycopene on BP (Engelhard, Gazer, & Paran, 2006; Paran, Novack, Engelhard, & Hazan‐Halevy, 2009; Ried & Falker, 2011; Yanai et al., 2017). Esculeoside A, a saponin found in tomatoes, has also been reported to suppress the activity of acyl‐CoA: cholesterol acyltransferase (ACAT), leading to an improvement in dyslipidemia (Nohara, 201. Furthermore, 13‐oxo‐9, 11‐octadecadienoic acid (13‐oxo‐ODA), a conjugated linoleic acid newly identified in tomato juice, was shown to have antidyslipidemic effects (Kim et al., 2012). Recently, we reported that unsalted tomato juice intake for 8 weeks improved hypertriglyceridemia in middle‐aged Japanese women (Hirose et al., 2015), which prompted us to investigate the effects of tomato juice on cardiovascular risk markers, such as BP, and lipid and glucose metabolism, in local Japanese male and female residents over a wider age range in this study.
2 MATERIALS AND METHODS
2.1 Study population
The par
