Yes they are used interchangeably and are closely related, but they are different!
Hydration is all about providing your skin with good concentrations of water. Epidermis or the outer and top layer of your skin consists of 4-5 layers. Water in epidermis originates from the deeper layers of epidermal cells and as we move upward it becomes less hydrated in surface cells. The outer layer that is in contact with air, Stratum Corneum (SC), consists of hard dry cells. Lower level of epidermis has about 70% water content whereas the outer layer, stratum corneum (SC), has an optimum hydration of around 20-30%. When the water content of SC goes below 10-20% skin will appear dry and scaly or even cracked. The fact that the air in contact with SC contains around 1% water doesn’t have any beneficial value for hydrating the cells in contact with it. In fact the cells keep losing water to the environment through evaporation. This process is called trans-epidermal water loss (TEWL). So how does your skin protect itself?
It has two main key protective systems: NMFs and Barrier function.
Your skin has a built-in protector against dry skin called natural moisturizing factors (NMFs). This is a mixture of amino acids, urea, mineral salts and organic acids that are water magnets and can attract and hold water in the SC. However NMFs can become depleted due to different factors such as poor health, genetics or harsh environment leaving your skin dry.
Your skin also has sebaceous glands. These glands are in charge of producing sebum. Sebum composed of fatty acids, fatty alcohols and waxes, together create an oily substance that coats the skin. Sebum plays an important role on skin, including lubricating and waterproofing the skin. It creates a skin barrier which will help with retaining moisture and give your skin a supple and healthy sheen. Barrier function is how effectively the lipids in your skin can protect your skin and prevent moisture from escaping.
As skin ages the SC begins to thicken and it becomes even harder to maintain a good level of hydration in them. Lipids in the skin also start to decline and this will compromise Barrier function leading to greater TEWL. Maintaining an optimum level of water in your SC is extremely important for having smooth and supple skin. These cells need to get hydration either from deeper layers of epidermal cells or from topical applications of hydrating products. The barrier function needs to work properly and NMFs should be at optimal levels.
Your skin is dynamic. The outer layer cells have a short life of around 30 days (depending on the age of the person). When the time comes the cells on top layer start to break down causing the skin to shed and be replaced by new healthy cells. This natural process is called desquamation. One of the causes of aging skin is that the desquamation process declines, the SC thickens, and as a result fine lines appear. That is why we keep exfoliating to facilitate desquamation. However, one of the easiest ways to help with skin desquamation is by keeping it well hydrated! If you keep the mature cells on the upper layer well hydrated they will swell and the necessary enzymes that work well under hydration do their job and weaken the bindings between cell and voila!!
Lack of water in skin can lead to many undesirable effects such as loss of vibrance and plumpness, flakiness, fine lines and sagging.
What shall we do?
Here are some key steps you can take to maintain skin hydration:
Drink water! Hydrate from inside.
Avoid over-cleansing which can impair the barrier function. Use a gentle facial cleanser. If you use regular soaps or facial cleanser with harsh cleansing agents (called surfactants) you are jeopardizing your barrier function by stripping healthy beneficial oil from your skin. This will cause more water loss and dryer skin. If you prefer to use solid bars (e.g., for environmental reasons) try Viso, our gentle cleansing pod formulated for sensitive skin, with zero waste packaging. If you are open to oil cleansers try Lumin8. If you like foam cleansers you may try Clair or Uplift. They both are gentle and effective. Uplift contains fruit acids that can help with hydration of skin.
Look for hydrating properties in skin care products. There are several ingredients that can increase the level of hydration in the skin. Hyaluronic acid is one of them. It has the capability of binding 1000 times its weight in water. Based on its molecular size it can either penetrate skin or create a film on skin and hydrate it. You can find Hyaluronic acid in Line-Break, Elevate, and Petale. Snow mushroom (Tremella Fuciformis) is another plant based ingredient with the same function. Facial masque Vipaka contains snow mushroom. Ceramides are another hydrating ingredient that can also help with maintaining a strong barrier. It can be found in Petale. Another star ingredient is Saccharide Isomerate, a deeply moisturizing, plant-derived ingredient. It mimics the carbohydrate complex of skin and is able to bind to skin and provides deep hydration that can last up to 72 hours. For example Bloom has a complex system that also includes this ingredient to provide your skin with a high level of hydration and nourishment. Provide your skin with a good level of peptides, amino acids, minerals and vitamins. Essentique skin care products are full of natural bio actives that can do wonders for your skin.
Take care of the lipids in your skin. As we age we are facing depletion of lipids in our skin and an external booster can be a game changer. Reine is absolutely divine and is packed with a diverse oils each chosen meticulously for their exceptional properties.
Exercise and Sweat! Have you ever looked at your face after exercising? It becomes plumped, dewy, and hydrated. It is mainly due to an increase of blood flow that allows oxygen and nutrients to nourish skin cells.