Objectives: This preliminary study aims to examine the effects of tomato juice, which can be easily consumed regularly, on the physical and psychological states of healthy adults in the Coronavirus era.
Design: Prospective observational study.
Materials and methods: Ten healthy adults (mean age, 39.7±4.2 years) who consumed 180 mL of tomato juice twice daily for 4 weeks were enrolled. Measurements were taken before and after 4 weeks of consumption for the items below. Five salivary stress biomarkers (cortisol, α-amylase, secretory immunoglobulin A, chromogranin A, and oxytocin) were measured using approximately 1ml of passively pooled saliva samples, which were stored at -20°C until measurement. Autonomic nervous system (ANS) activity was evaluated using an acceleration pulse wave meter. Skin moisture content and transepidermal water loss (TEWL) were measured using Multi Display devices® MDD4 with specific probes. Subjective psychological states were assessed using Profile of Mood Status (POMS2®) and a survey on skin condition was conducted.
Results: As for salivary stress biomarkers, tomato juice intake reduced cortisol and significantly increased oxytocin levels (p = 0.0427). No significant changes were observed in ANS activity. POMS2® results showed a significant decrease in confusion and bewilderment (p = 0.0207). Skin moisture content increased significantly (p = 0.0011), whereas TEWL decreased. The skin condition survey revealed significant changes in 10 parameters.
Conclusions: Tomato juice, which can be easily consumed regularly, may alleviate the stress of healthy adults in the Coronavirus era, supported by positive changes in salivary stress biomarker levels, skin moisture content, TEWL, and POMS2® results of this preliminary study.