Effect of Amount of Daily Water Intake and Use of Moisturizer on Skin Barrier Function in Healthy Female Participants.

Background: It is well known that adequate water intake and moisturizer application improves skin barrier function.

Objective: This study was conducted to analyze the effects of daily water intake and moisturizer application on skin barrier function and the degree of response to barrier recovery.

Methods: Participants with daily water intake more than 1 L were classified as high daily water intake group (H) and those with less than 1 L as low daily water intake group (L). Each group was subcategorized into four groups according to intervention method: additional water intake (H1, L1), moisturizer (H2, L2), both (H3, L3), and control (H4, L4). Transepidermal water loss (TEWL) and stratum corneum hydration (SCH) were measured at baseline during the 2nd and 4th week.

Results: A total of 43 participants completed the study (H: 22, L: 21). At baseline, there was no significant difference in SCH and TEWL in any on the anatomical sites between the high daily water intake and low daily water intake groups. However, SCHs of left forearm (group H2, p=0.004; group H3, p=0.004), left hand dorsum (group H2, p=0.010; group H3, p=0.026), and left shin (group H2, p=0.016; group H3, p=0.001) in group H2 and H3 were significantly increased in the 4th week as compared to the baseline values.

Conclusion: The results suggest that the degree of water intake may be related to improved skin barrier function. However, application of additional moisturizers had more favorable impact on skin hydration as compared to additional water intake.