Ingestion of coffee polyphenols suppresses deterioration of skin barrier function after barrier disruption, concomitant with the modulation of autonomic nervous system activity in healthy subjects

Figures & data

Figure 1. Effects of CPP on skin functions. After three weeks of ingestion of a CPP or placebo beverage, the skin of the ventral side of the upper forearm was treated with a 10% SDS solution for 30 min. TEWL (A), capacitance (B), and conductance (C) were measured at baseline (Pre) and immediately (T0), 1 day (D1) and 7 days (D7) after SDS treatment. Data are mean ± SD, n = 10. *: P < 0.05, significant difference in placebo group vs. CPP group (two-way repeated measures ANOVA). †: P < 0.05, ††: P < 0.01, significant differences vs. placebo pre-value in the placebo group (Dunnett test). #: P < 0.05, ##: P < 0.01, significant differences vs. CPP pre-value in the CPP group (Dunnett test).

Table 1. HRV indices during sleep at baseline and 4 weeks after ingestion.

	Placebo			CPP
	Baseline	4 weeks	⊿	Baseline	4 weeks	⊿
Sleep time (min)	362.4 ± 67.1	355.5 ± 51.8	−6.9 ± 60.3	345.4 ± 46.5	353.2 ± 59.2	7.8 ± 37.2
Heart rate (bpm)	55.6 ± 4.0	56.7 ± 5.9	1.1 ± 3.2	55.0 ± 4.7	55.2 ± 4.6	0.2 ± 2.3
RMSSD (ms)	56.6 ± 25.7	50.8 ± 22.8	−5.8 ± 8.0	55.0 ± 17.0	56.6 ± 21.2	3.6 ± 6.7*
HF nu	48.5 ± 8.9	45.8 ± 11.1	−2.7 ± 4.6	44.3 ± 11.0	48.4 ± 9.2	4.1 ± 5.7*
LF/HF index	1.75 ± 0.62	2.08 ± 0.94	0.33 ± 0.44	2.04 ± 0.78	1.78 ± 0.56	−0.27 ± 0.39*

Abbreviations: HRV, heart rate variability; RMSSD, root mean square of successive differences; HF nu, high-frequency normalized units; LF/HF index, low-frequency / high-frequency index. Data are expressed as the mean ± SD. ⊿: The variation in parameter from baseline in 4 weeks. Data were compared using paired Student t test (comparisons between Placebo and CPP).

* p < 0.05.

Figure 2. Effects of CPP on salivary cortisol. Saliva was obtained for cortisol measurements in the morning and night at baseline and four weeks of ingestion of CPP or placebo beverage. Data are mean ± SD, n = 10.