A Randomized, Placebo-Controlled Study on the Safety and Efficacy of Daily Ingestion of Green Tea (Camellia Sinensis L.) Cv
Total Page：16
File Type：pdf, Size：1020Kb
nutrients Article A Randomized, Placebo-Controlled Study on the Safety and Efficacy of Daily Ingestion of Green Tea (Camellia sinensis L.) cv. “Yabukita” and “Sunrouge” on Eyestrain and Blood Pressure in Healthy Adults Mari Maeda-Yamamoto 1,*, Mie Nishimura 2 ID , Nobuyoshi Kitaichi 3, Atsushi Nesumi 4, Manami Monobe 5, Sachiko Nomura 5, Yukihiro Horie 3, Hirofumi Tachibana 6 and Jun Nishihira 2 1 Agri-Food Business Innovation Center, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki 305-8517, Japan 2 Department of Medical Management and Informatics, Hokkaido Information University, Ebetsu, Hokkaido 069-8585, Japan; [email protected] (M.N.); [email protected] (J.N.) 3 Department of Ophthalmology, Health Sciences University of Hokkaido, Ishikari-gun, Hokkaido 002-8072, Japan; [email protected] (N.K.); [email protected] (Y.H.) 4 Institute of Fruit and Tea Science, NARO, Makurazaki, Kagoshima 898-0087, Japan; [email protected] 5 Institute of Fruit and Tea Science, NARO, Shimada, Shizuoka 428-8501, Japan; [email protected] (M.M.); [email protected] (S.N.) 6 Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Fukuoka 812-8581, Japan; [email protected] * Correspondence: [email protected]; Tel.: +81-29-838-8800 Received: 25 March 2018; Accepted: 3 May 2018; Published: 6 May 2018 Abstract: The green tea (Camellia sinensis L.) cultivar “Sunrouge” contains anthocyanins, catechins and flavonols. To determine whether ingesting green tea containing anthocyanins improves visual function and blood pressure (BP) in healthy adults, a randomized, double-blind, placebo-controlled study was performed. A total of 120 healthy subjects, aged between 20 and 60 years and with a systolic BP (SBP) value of ≤125 and <155 and a diastolic BP (DBP) value <95, or a DBP of ≤75 mmHg and <95 mmHg and a SBP <155 mmHg, were randomly assigned to one of three groups. For 12 weeks, the placebo group received barley extract without catechin; another group received “Sunrouge” extract containing 11.2 mg anthocyanin and 323.6 mg epigallocatechin-3-O-gallate (EGCG); and a third group received “Yabukita” extract containing 322.2 mg EGCG. Home BP, accommodation ability, visual analog scale questionnaires for eyestrain, and metabolic-associated markers were analyzed at weeks 0, 4, 8, and 12 of the intake period. The ingestion of “Sunrouge” tea significantly improved accommodation ability and eyestrain in subjects younger than 45 years and in subjects who operated visual display terminals every day. It also elevated BP. “Yabukita” tea ingestion significantly increased serum adiponectin levels. No adverse effects were observed. We conclude that long-term intake of “Sunrouge” tea containing anthocyanins and flavonols might improve visual function. Keywords: green tea cv. “Sunrouge” or “Yabukita”; anthocyanins; flavonols; eyestrain reducing effect; blood pressure elevating effect; adiponectin level increasing effect 1. Introduction In recent years, fatigue and eyestrain associated with the use of visual display terminals (VDT) have become increasingly prevalent among younger individuals. In Japan, the penetration ratios of personal computers and smartphones in households reached 76.8% and 72.0%, respectively, in 2015 [1], Nutrients 2018, 10, 569; doi:10.3390/nu10050569 www.mdpi.com/journal/nutrients Nutrients 2018, 10, x FOR PEER REVIEW 2 of 13 In recent years, fatigue and eyestrain associated with the use of visual display terminals (VDT) have become increasingly prevalent among younger individuals. In Japan, the penetration ratios of Nutrientspersonal2018 computers, 10, 569 and smartphones in households reached 76.8% and 72.0%, respectively, in2 2015 of 13 [1], while the ownership rates of mobile phones reached 128.0% in 2016 [2]. Longer VDT operation whiletimes theresult ownership in increased rates stress of mobile and fatigue phones in reached different 128.0% body inregions, 2016 [2 such]. Longer as tired VDT eyes operation and eye times pain result(91.6%), in increasedstiffness in stress the andshoulders fatigue and in different neck (70.4%), body regions,and lower such back as tired pain eyes (26.6%) and eye[3]. painEyestrain (91.6%), is stiffnessincreasing in due the shouldersto long hours and neckof VDT (70.4%), operation and lowerand its back consequences, pain (26.6%) such [3]. as Eyestrain sleep deprivation is increasing or duemental to longstress. hours It has of been VDT reported operation that and approximately its consequences, 90% such of the as Japanese sleep deprivation population or has mental eyestrain, stress. Itmaking has been it one reported of the factors that approximately that lowers their 90% quality of the Japaneseof life (QOL) population [3]. Research has eyestrain, and drug making development it one offor the eyestrain factors are that scarce; lowers functional their quality foods oflife are(QOL) expected [3]. to Research contribute and to drug the treatment development of eyestrain. for eyestrain are scarce;Green functional tea (Camellia foods sinensis are expected L.) is consumed to contribute worldwide, to the treatment with large of eyestrain.quantities being consumed in JapanGreen and tea China, (Camellia where sinensis it hasL.) been is consumedused for medicinal worldwide, purposes with large for centuries. quantities Green being tea consumed contains inmany Japan functional and China, ingredients where such it has as beencatechins, used caffeine, for medicinal flavonols, purposes vitamins, for and centuries. dietary fiber Green. It has tea containsbeen reported many to functional have various ingredients bioregulatory such asfunctions, catechins, such caffeine, as anti- flavonols,carcinogenic vitamins, and anti and-metastatic dietary fiber.[4], anti It has-obesity been reported[5], anti-diabetes to have various[6], anti bioregulatory-hypercholesterolemic functions, such[7,8], asantioxidative anti-carcinogenic [9], anti and- anti-metastaticcardiovascular [[10],4], anti-obesity anti-allergic [5 [11],], anti-diabetes and anti-dry [6],-eye anti-hypercholesterolemic activities [12], and it is known [7,8], antioxidative to improve the [9], anti-cardiovascularintestinal flora. The[ 10tea], cultivars anti-allergic (cv.) [11 “Yabukita”], and anti-dry-eye and “Sunrouge” activities [13], [12], used and itas is test known samples to improve in this thestudy, intestinal contain flora. catechins, The tea cultivarsincluding (cv.) epigallocatechin “Yabukita” and-3- “Sunrouge”O-gallate (EGCG), [13], used which as test are samples believed in this to study,prevent contain lifestyle catechins,-related includingdiseases. epigallocatechin-3-In addition, “Sunrouge”O-gallate tea (EGCG), is rich in which antioxidative are believed anthocyanins to prevent lifestyle-related[14–16]. It has been diseases. reported In addition, that tea “Sunrouge” catechins have tea is richan anti in antioxidative-hypertensive anthocyaninseffect [17,18], [14 while–16]. Itanthocyanins has been reported are well that known tea catechins to reduc havee eyestrain an anti-hypertensive [19,20]. “Sunrouge” effect [17 water,18], whileextract anthocyanins suppressed areacetylcholinesterase well known to reduce activity eyestrain in human [19,20 ].neuroblastoma “Sunrouge” water SK-N extract-SH cells suppressed [15]. Neostigmine acetylcholinesterase methyl activitysulfate, which in human is an neuroblastomaacetylcholinesterase SK-N-SH inhibitor, cells is [ 15used]. Neostigmineas an eye-focusing methyl medicine sulfate, [21]. which is an acetylcholinesteraseTherefore, in this inhibitor, study, to is clarify used as the an effects eye-focusing of ingesting medicine “Yab [21ukita”]. green tea and “Sunrouge” greenTherefore, tea on eyestrain in this study, and tohypertension, clarify the effects we conducted of ingesting a “Yabukita”12-week, randomized, green tea and double “Sunrouge”-blind, greenplacebo tea-controlled on eyestrain trial in and Japanese hypertension, adults (aged we conducted 20–60 years) a 12-week,with slightly randomized, elevated blood double-blind, pressure placebo-controlled(BP). trial in Japanese adults (aged 20–60 years) with slightly elevated blood pressure (BP). 2. Materials and Methods 2.1. Study Design This was a double-blind,double-blind, randomized, placebo-controlledplacebo-controlled study. TheThe studystudy protocolprotocol isis shownshown in Figure1 .1. The The subjects subjects were were recruited recruited by the by Hokkaido the Hokkaido Information Information University University and were and fully were informed fully regardinginformed regarding the content the and content methods and methods of this study. of this Writtenstudy. Written informed informed consents consents were obtainedwere obtained from subjectsfrom subjects before before their enrollment.their enrollment. The screeningThe screening for the for first the first volunteers volunteers started started in July in July 2015 2015 and and the studythe study was was completed completed in January in January 2016. 2016. Figure 1. Schematic representation of the study/protocol. Nutrients 2018, 10, 569 3 of 13 2.2. Subjects We recruited a total of 258 healthy volunteers (aged 21–55 years), of which 120 subjects (50 men, 70 women) were eligible. Key eligibility and exclusion criteria are shown in Table S1. The 120 eligible subjects were randomly assigned to the “Yabukita” group, “Sunrouge” group, or placebo group stratified by sex, age, hospital-measured