Does dietary fluid intake affect skin hydration in healthy humans? A systematic literature review

Abstract

Additional dietary water intake may increase stratum corneum hydration. The underlying biological mechanism for this possible relationship is unknown. Whether this association also exists in aged subjects is unclear. Research is needed to answer the question whether increased fluid intake decreases signs of dry skin.

Narrative Review of Hydration and Selected Health Outcomes in the General Population

“…The stratum corneum (SC) layer of the epidermis is the primary location of the barrier function; however, both the dermis and the multilayered epidermis are important for maintenance of barrier integrity [32]. Measurements for skin barrier function and hydration include transepidermal water loss (TEWL), SC hydration, “deep” skin hydration, clinical evaluation of dryness, roughness and elasticity, skin relief parameter, the average roughness, evaluation of skin surface morphology, skin smoothness and roughness, extensibility, sebum content, and skin surface pH [24].…”

“…For hydration and skin health, a 2018 systematic review was identified [24], which included five intervention studies. Of these studies, four measured surface hydration and reported increased SC hydration following additional intake of 2 L daily of water over a period of 30 days [33,34,35] or additional intake of 1 L per day for a period of 42 days [36].…”

“…Measurements of skin elasticity [36], extensibility [33], and the ability of the skin to return to its original state [35] were greater with additional water intake. However, the review authors concluded that the evidence is weak in terms of quantity and methodological quality, and risk of bias in the interventional studies is extremely high [24]. With the exception of providing an explicit statement of questions being addressed and clarifying if a review protocol existed, the 2018 systematic review fulfilled all required PRISMA reporting items (Table 1).…”

“…Our updated search resulted in 178 titles (Figure 1), but the vast majority assessed topical applications (e.g., moisturizers), oral ingestion of supplements or herbals, or skin conditions in disease states. No new intervention studies were found when compared with the 2018 systematic review [24].…”

Dry skin and the use of leave‐on products in nursing care: A prevalence study in nursing homes and hospitals

“…There are numerous factors which may cause skin dryness like endocrine disorders, genetic predisposition, climate or medication (Paul et al, ; White‐Chu & Reddy, ). Fluid intake is believed to affect the skin hydration as well, but the empirical evidence supporting this association is week (Akdeniz, Tomova‐Simitchieva, Dobos, Blume‐Peytavi, & Kottner, ), especially in care‐dependent aged adults (Akdeniz, Boeing, et al, ).…”