Fruit Juice Supplementation Alters Human Skin Antioxidant Levels <Emphasis Type="Italic">In Vivo</Emphasis>: Case Study of Korean Adults by Resonance Raman Spectroscopy

Carotenoids, found in many fruits and vegetables, are antioxidants that protect human skin from UV radiation. In humans, fruit and vegetable intake increases carotenoid contents in skin, which are conventionally assessed by invasive blood tests. In this study, 47 healthy Korean subjects (volunteers) consumed fruit juice containing tomato, apple, strawberry, or grape three times per week for 6 weeks. Skin antioxidant levels were measured by non-invasive resonance Raman spectroscopy. The correlation between skin carotenoid (SC) score with demographic data (age, height, weight) and juice supplementation and changes in SC scores among groups were analyzed. Variations in skin antioxidant levels increased with juice supplementation (p < 0.05). Fruit juice intake was significantly correlated with SC score, indicating increased skin antioxidant levels. Grape and tomato increased skin antioxidant levels and showed higher antioxidant activity than other fruits. Fruit juices containing high levels of carotenoids and antioxidants may provide modest benefits to human health.