Blemishes, rosacea, and acne flare-ups can be a sign of a damaged skin barrier, as the bacteria that causes acne is more easily able to penetrate the skin. It all starts with the skin barrier. This is the outermost layer of the skin and the first line of defence.
The skin barrier functions to keep pollutants and bacteria out while keeping moisture in. Helping it to do this are naturally occurring fats, known as lipids. These lipids are made up of 50% ceramides, 25% cholesterol and 10-25% fatty acids. The Lipids that mimic the skin's natural lipids include ceramides, natural cholesterol, and fatty acids. The so-called golden ratio for these lipids would 2% pure ceramides, 4% natural cholesterol and 2% fatty acids.
Over time, the depletion of ceramides, cholesterol and fatty acids in the skin can result in moisture loss, dryness, and cracking. This can also cause inflammation and irritation from the allergens and environmental toxins your skin encounters daily. Ongoing skin inflammation is pro-ageing.
Good skin care preserves and protects the skin barrier, maintains the right pH, and keeps it functioning optimally. This should be the first step in any good skin care routine — making sure you are replenishing your skin’s ceramides and fatty acids.
What weakens the skin barrier?
The skin barrier weakens with age and can be affected by some systemic health issues.
Have you ever wondered why your skin gets dry, flaky, irritated, itchy, or sensitive?
These are all signs of a weakened skin barrier function. Your Stratum Corneum, or outermost layer of the skin, is your skin barrier. The Stratum Corneum’s job is to protect your skin and body from the external environment. When we talk about how strong this barrier is we refer to it as your skin barrier function. The skin barrier is designed to be impermeable, meaning it keeps water in and bacteria and microorganisms out.
Think of your skin as a brick wall. Skin is made up of “bricks” (protein from skin cells) and “mortar” (lipids and important fats). The lipid layer – aka your skins oil – is the glue that holds the wall together. It creates skin that is strong, hydrated, and soft. It holds the natural moisturisers in and keeps bacteria and environmental chemicals out. After the age of 40 the amounts of lipids decrease significantly(mainly due to hormone changes) which is why we are more prone to dry skin as we age. Excessive UV damage will exacerbate this.
When the lipids in the mortar are damaged or depleted by environmental conditions, harsh products or handling, our skin loses water, gets dried out, and becomes more permeable to irritants and allergens. Once irritants and allergens penetrate the epidermis, it can trigger inflammation.
Harsh products including solvents, detergents, perfumes, and irritating chemicals can weaken the barrier. Excessive cleansing with soap and water can break down the barrier and cleansing in hot water can strip lipid from the skin.
If your skin was normal and then becomes dry, red, irritated, sensitive and develops atypical breakouts, then you may have an impaired skin barrier.
Ceramides and the skin barrier
Skin that is well moisturised and nourished and has a good water-to-oil balance, is a more resilient skin.
Forming part of the protective function of our topmost layer of skin are ceramides. Just like cholesterol and essential fatty acids, they are part of our skin’s naturally occurring lipids. They are essential in supporting the skin barrier function and retaining moisture. Without ceramides, skin can become dry, itchy, irritated, or dull.
Ceramides make up about 50% of the skin barrier. As well as keeping moisture in and irritants out, they also play an important role in the repair of the skin barrier.
Over time, though, ceramides can become depleted. To maintain your optimal skin barrier function and keep it looking healthy, you need to ensure the right balance of ceramides, cholesterol, and fatty acids. If your skin lacks adequate ceramides, it can lead to a few skin concerns that go beyond dryness or dullness, such as psoriasis or eczema. When ceramide levels are low, your protective skin barrier is weakened, allowing moisture to escape.
Many people with acne or oily skin find their skin becomes more sensitive and more easily irritated when using skin care products designed to reduce the oils in their skin. In trying to treat their acne, they also may be unintentionally stripping away the skin’s natural defence and making their skin even more vulnerable.
By applying ceramides to your skin through your skin care routine, you can help restore the skin’s barrier and retain more moisture. This will help strengthen your skin and make it less reactive. However, keep in mind that ceramides need the support of cholesterol and amino acids to do their best work; they are not nearly as effective when they are used on their own.
Cholesterol and the skin barrier
Cholesterol is another element naturally found in the skin barrier, but also can be found as an ingredient in skin care products. Unlike cholesterol in the diet, cholesterol in skin care products is beneficial to the skin. It helps accelerate the recovery of the skin barrier function and improves the appearance of skin elasticity.
It works in tandem with ceramides and fatty acids to replenish and restore the skin, helping maintain a healthy skin barrier that can keep invaders out and moisture in. Just like other lipids, cholesterol hydrates the skin and keeps it feeling smooth.
Fatty acids and the skin barrier
Fatty acids also form part of the skin barrier and ensure the healthy function of our skin.
Most of us are more familiar with the important role essential fatty acids play in our diet than the role they play in our skin barrier. Just like our bodies need essential fatty acids, such as Omega-3 and Omega-6, our skin needs a good supply of fatty acids.
Omega-3 is an oil rich in α-Linolenic Acid while Omega-6 is rich in Linoleic Acid, and both are essential nutrients in our diet as they cannot be synthesised by the body.
Even though we may have a nutrient-rich diet and are getting enough essential fatty acids, this may not be enough for our skin. Essential Fatty Acids that are ingested can become oxidised in the liver before being able to deliver their benefits to the skin, so direct topical application can be beneficial.
Fatty acids help protect skin from cellular damage when exposed UV light and thereby play a role in reducing photo-ageing. Therefore, we like to see ceramides in moisturisers and support the inclusion of appropriate skin oils in skin care routines for dry and compromised skin types.
So, when next see an ingredient list that has ceramides, cholesterol, or fatty acids, know that they are there to help your skin. These are fats that naturally occur in the skin and are important for the skin barrier and keeping it functioning at its best.