We conducted an open-label, single-arm study at the Menopause Clinic of the Tokyo Medical and Dental University. The study protocol was reviewed and approved by the Tokyo Medical and Dental University Review Board, and written informed consent was obtained from all participants. The study was conducted in accordance with the Declaration of Helsinki .
Ninety-five Japanese women participated in this study. The inclusion criteria were as follows: ages between 40 and 60; having at least one menopausal symptom on the Menopausal symptom scale (MSS) (score >1). The exclusion criteria were as follows: medication for hypertension, dyslipidemia, diabetes, or other cardiovascular diseases; intake of vitamins, lycopene, GABA or other supplements that could affect the parameters to be evaluated; allergy to tomato or tomato products. The participants were recruited through advertisements posted in our hospital and in the patients’ social network. The participants were classified as follows: premenopausal (regular menstrual cycles in the past 3 months), perimenopausal (a menstrual period within the past 12 months but a missed period or irregular cycles in the past 3 months), postmenopausal (no menstrual period in the past 12 months), or had surgically or medically induced menopause (hysterectomy or chemotherapy for breast cancer).
From 2 weeks before the start until study termination, the participants refrained from foods and drinks rich in tomatoes and tomato products. After the run-in period, each participant was asked to consume 200 mL of unsalted tomato juice (Nippon Del Monte, Gunma, Japan) twice daily, just before breakfast and dinner, for 8 weeks. The nutritional composition of the tomato juice used in the current study is shown in Table 1. The product was manufactured in compliance with the Food Safety System Certification (FSSC) 22000 adopted by the Global Food Safety Initiative (GFSI). Adherence to the study protocol was confirmed by checking the participants’ diaries including the records of tomato juice consumption.
The participants’ menopausal symptoms were evaluated using MSS, Hospital Anxiety and Depression Scale (HADS), and Athens Insomnia Scale (AIS) before, and after 4 and 8 weeks of study participation. At each time point, body composition, blood pressure, heart rate, and REE, as well as serum levels of TG, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and plasma levels of glucose and hemoglobin A1c (HbA1c) were measured.
The MSS was validated and used in previous studies for participants to rate the severity of ten menopausal symptoms . We evaluated vasomotor symptoms (hot flashes, perspiration, and chilliness); somatic symptoms (irregular heartbeat, headache/dizziness, tiredness, and aching joints/muscles); and psychological symptoms (insomnia, irritability, and depressed mood) using a 4-point Likert scale, depending on how often each symptom affected their daily life: none (never, 0 points); mild (rarely, 1 point); moderate (sometimes, 2 points); severe (very often, 3 points). MSS scores were calculated as the total score for the 10 aforementioned symptoms.
Developed by Zigmond and Snaith as a questionnaire , the HADS is a reliable instrument for screening clinically significant anxiety and depression in women; the questionnaire was translated into Japanese by Kitamura et al. . The AIS was developed as a brief, easy-to-administer self-assessment questionnaire for determining insomnia severity according to the International Classification of Disease, Tenth Revision. The internal consistency and test-retest reliability of the AIS was previously confirmed . The current study followed the protocol reported earlier , who measured the effect of supplementation with grape seed proanthocyanidin extracts on determining insomnia severity using AIS  and screening of clinically significant anxiety and depression using the Japanese version of HADS questionnaire .
The body composition of the participants, including height, weight, body mass index, fat mass, and muscle mass, was assessed using a body composition analyzer (MC190-EM; Tanita, Tokyo, Japan). Participants’ systolic and diastolic blood pressure and heart rate were also measured using a vascular screening system (VS-1000; Fukuda Denshi, Tokyo, Japan). Additionally, REE was measured using a portable, indirect calorimeter (Metavine-N VMB-005 N; Vine, Tokyo, Japan).
Blood samples were collected by antecubital venipuncture and were centrifuged for the collection of serum. The serum and plasma samples were sent within 3 days of sampling to SRL, Inc. (Tokyo, Japan). The levels of serum lipids, plasma glucose, and HbA1c were assayed according to standard techniques.
Statistical analyses were performed using GraphPad Prism version 5.02 (GraphPad Software, San Diego, CA, USA) and IBM SPSS Statistics version 20 (IBM Corporation, Armonk, NY, USA). After testing the normality of each valuable using Shapiro-Wilk test, the variables with Gaussian distribution were evaluated with parametric tests (One-way repeated measures ANOVA and paired t-test) and those without were with non-parametric tests (Friedman and Wilcoxon signed-rank tests). One-way ANOVA and Kruskal-Wallis test were used for the evaluations of baseline characteristics among four different menopausal status groups and postprandial time for blood sampling. P-values < 0.05 were considered statistically significant.