Kinetics of the carotenoid concentration degradation of smoothies and their influence on the antioxidant status of the human skin in vivo during 8 weeks of daily consumption.

The antioxidant status of the skin shows constant alterations depending on nutrition and other lifestyle factors. Carotenoids can serve as marker substances for the antioxidant status of the epidermis in vivo. The carotenoid concentration of 2 homemade green smoothies and a commercial green smoothie, all containing fruits and vegetables, was assessed by resonance Raman spectroscopy. Furthermore, a pilot study was conducted to investigate changes of the cutaneous carotenoid concentration of 20 healthy volunteers under the daily intake of either a homemade smoothie or the commercial smoothie in vivo using reflectance spectroscopy. We hypothesized that higher carotenoid concentrations in the homemade smoothies compared to those of the commercial one would lead to a faster increase of the cutaneous carotenoid concentration in healthy volunteers. The measurements of the homemade smoothies showed notably higher initial carotenoid concentrations (7.6 ±0.8)*10-4arbitrary units (a.u.) (smoothie A) and (10.4 ± 0.6)*10-4 a.u. (smoothie B) compared to the commercial smoothie (5.8 ± 0.2)*10-4 a.u. Nevertheless, the commercial smoothie showed a higher stability of carotenoids over 24 hours. 8 weeks after daily consumption of the homemade smoothies, volunteers showed an insignificant increase of cutaneous carotenoids from (4.5 ± 0.1)*10-4 a.u. at baseline to (4.8 ± 0.3)*10-4 a.u. (means ± standard error of the mean). The volunteers consuming the commercial smoothie showed an insignificant increase of cutaneous carotenoids from (4.3 ± 0.2)*10-4 a.u. to (4.7 ± 0.2)*10-4 a.u. after 8 weeks. The observed increase of cutaneous carotenoid concentrations could be classified as a strong tendency. Fresh homemade smoothies can exhibit a higher carotenoid concentration compared to commercial smoothies but need to be consumed immediately after preparation.

Antioxidants in Asian-Korean and caucasian skin: the influence of nutrition and stress.

BACKGROUND: The antioxidant status of the human skin provides protection against the destructive action of free radicals. Most antioxidants cannot be synthesized by the human organism itself, but have to be ingested with a healthy nutrition rich in fruit and vegetables. The Korean cuisine is known to be one of the healthiest worldwide. This binational study investigated the cutaneous carotenoid concentrations in German subjects, South Korean subjects and immigrant Korean subjects resident in Germany and examined whether dietary- and lifestyle-related differences are reflected in the cutaneous carotenoid concentrations. METHODS: Measurements of the carotenoid concentrations of 714 healthy volunteers were performed using a non-invasive spectroscopic measurement system based on reflectance spectroscopy. RESULTS: In the present study South Korean residents showed a significantly higher antioxidant status than both native German residents and Korean immigrants living in Germany (p < 0.001). The first generation of Korean immigrants to Germany over the age of 50 mostly preserved Korean dietary habits, showing significantly higher concentrations (p < 0.001) than the German-born second and third Korean generations under the age of 50. CONCLUSION: The results of the study indicate that a healthy nutrition alone does not provide a high antioxidant status unless the stress exposure can be reduced simultaneously.