The 4 secrets of modern skin hydration
If you ask me, there are two nonnegotiable skincare steps that everyone should perform regardless of age, ethnicity, gender or geographical location: hydrate and wear sunscreen. While, skin moisturization existed for over 10,000 years, daily sunscreen use was incorporated into our routine “only” in the past century. Today, hydrators and moisturizers are popular products as dryness is on the rise courtesy of urban life and increased longevity. Thus, my ancestors and I agree on the importance of skin hydration; we approach this issue very differently as modern scientific and technological skin care breakthroughs beautifully harvest the power of water.
Although water does not contain organic nutrients nor provide energy, it is key for life. In the skin, water determines looks (radiant, glowing complexion) and function. Proper skin moisturization reduces systemic inflammation(1) providing benefits that beyond skin deep (healthy skin, healthy body). All skin types are susceptible to water loss resulting in a skin that is dry and flaky, feels tight and itchy, and looks red and dull. Over time, dehydration triggers uneven pigmentation and susceptibility to environmental stressors (solar radiation, chemicals and pollution) as well as saginness and laxity due to more fragile (dehydrated) collagen and elastin. One of the hallmarks of dehydrated skin is redness, even when we cannot see it due to our skin color. Redness is the visual manifestation of inflamed skin. Chronic inflammation must be controlled at all costs. It is an aging accelerant and an anti-aging saboteur that promotes destruction and delays repair.
Skin moisturization/hydration has evolved significantly in the past century; replacing the greasy and heavy creams our grandmothers wore at night with lightweight and elegant multifunctional non-occlusive formulations. To properly hydrate our skin, 21st century-style, we need to (1) supply water to the skin, (2) trap it there, (3) hydrate our cells and (4) repair barrier damage. Let’s take a deep dive into these 4 modern skin hydration secrets.
Although research linking water intake to increased skin hydration in healthy individuals is still inconclusive, in my opinion, this makes sense. Doesn’t it? Drinking water or eating water-loaded fruits and veggies (watermelon, berries, plums and cucumbers) hydrate all our organs. However, our skin is not first in line when it comes to water distribution and other vital organs take priority. To deliver the much needed water to our skin, we need to drink enough water to quench our organs thirst first. It is recommended that we drink 8 glasses of water per day (not considering caffeinated or sugar-loaded drinks). Avoiding products containing non-hydrating alcohols (ethanol, isopropyl alcohol, alcohol denat, and methanol) and preventing prolonged exposure to dry air or hot water may also boost skin hydration. Proper skin hydration is one of the best defenses against inflammation, free radicals, toxins and normal metabolism byproducts. But bringing water to the skin is only the first step. Water needs to be trapped in the skin to provide long-lasting hydration and associated benefits.
(2) Let's seal the deal
One of the most hydrophilic (water-loving) molecules in nature, Hyaluronic Acid (HA), is used by our skin to lock hydration. HA acts as a sponge holding 1,000 times its own weight in water. As we age we naturally lose HA, a process that may start as early as our 20s. By our 40 and 50s we lose about half of the skin HA. Restoring HA is not as simple as applying serums or creams containing this molecule. HA is too large to penetrate the skin. Cosmeceutical companies developed two approaches to bypass the HA size restrictions: bioengineered low molecular weight HA (LMW-HA) and isolated HA inducers. Smaller versions of HA (LMW-HA) may penetrate the skin, but unfortunately with smaller size comes a smaller benefit: lower hydration capacity. Additionally, all HA molecules, regardless of size, are rapidly degraded in the skin (2-3 hours half-life) further limiting skin hydration capacity. The second approach, my prefered, is to induce the activate the production of skin HA (endogenous HA). The challenge here is delivering HA-inducers to the dermis and epidermis. My two favorite HA-inducers are whey protein and an exopolysaccharide derived from Kopara(2). Furthermore, whey protein induces collagen and fibronectin, resulting in firmer and more elastic skin and the Kopara exopolysaccharide improves barrier function preventing water loss. Green tea-derived epigallocatechin gallate (EGCG), a very powerful antioxidant, also induces HA while preventing its degradation (win-win situation). I love multifunctional ingredients!
Although not related with HA, we cannot close this section without mentioning a rising star: snow mushroom (Tremella fuciformis). Recent research showed that this extract has the ability to hold nearly 500 times its own weight in water while providing strong anti-oxidant and anti-inflammatory benefits, pretty impressive! Time will tell if this Super-Shroom is the real deal.
(3) A game changer: improving cellular hydration
The 2003 Nobel Prize in Chemistry(3) and tons of academia and industry research showed that skin hydration is incomplete unless water is delivered inside our cells. Intracellular water balance is required for energy production, stress control and cellular detoxification. Well-hydrated cells are fully energized, clean and ready to function at their best. Aquaporin-3 (AQP3) is a channel that transports water and glycerol inside our cells controlling cellular hydration, epidermal differentiation and proliferation, barrier formation and wound healing. As we age, dermal and epidermal AQP3 levels decrease resulting in dehydrated dysfunctional cells that are unable to preserve skin health, elasticity and firmness. AQP3 is a multi-dimensional structure and therefore cannot be directly added in skincare products. However, we can use AQP3 inducers such as niacinamide, glycerin, caffeine, ginseng extracts, all-trans retinoic acid, glyceryl glycosides, green tea and tea tree oil to restore and preserve cellular hydration.
(4) Patching microscopic skin holes makes a huge difference
Our grandmothers’ only option to alleviate skin thirst was to slather on a thick occlusive or semi-occlusive cream. While occlusiveness prevents water loss, it does so at a cost. Ingredients such as cocoa butter, lanolin, shea butter and mineral oil provided temporary skin hydration but often produced unwanted pimples.
Compromised skin, defined as skin that no longer has the capacity to protect and maintain itself (barrier dysfunction), is a component of dehydrated, inflamed and sensitive skin. Regardless of origin, compromised skin contains microscopic holes that facilitate water evaporation and allow pollutants and microorganisms direct access to our skin. These holes are produced by alterations in the production of skin lipids and phospholipids. Adding these natural and skin identical molecules to skin care products immediately repair these holes restoring skin hydration. Phospholipids derived from sunflower and soy, cholesterol, ceramides and free fatty acids patch these holes beautifully, hydrating the skin with minimal occlusiveness making them ideal for all skin types including acne-prone skin.
Final remarks: Skin hydration cannot be faked. Even the best makeup in the market will not cover a dull (dehydrated) complexion. Although a healthy diet and proper water intake are important to maintain radiant skin, other factors that address tissue and cellular long-lasting hydration are equally fundamental. Keeping our skin hydrated is achievable but it is also a lifelong dynamic commitment. With these 4 secrets of modern skin hydration, science and technology are making this commitment successfully fun and enjoyable.