Ingredients matter: what to look for when choosing skin care

What should be considered when choosing skin care products, what vitamins are needed to maintain skin health and what factors affect its condition, UNN tells with reference to the article by the BBC.

Cosmetic skin care products often contain many different ingredients: vitamin A or retinol, which helps fight the signs of aging; vitamin C, which improves complexion and protects the skin from negative environmental influences; hyaluronic acid, which reduces dryness and wrinkles; vitamin E, which has healing and soothing properties. This is not a complete list of such ingredients.

From 2020 to 2022, the number of searches for individual ingredients on the Net-a-Porter online platform increased by almost 700%. Also last year, the query "What does a retinol serum do?" became one of the most popular searches on Google in the skincare category. A study conducted in the United States in 2022 showed that 61% of millennials and 48% of Generation Xers consider specific ingredients important when choosing skincare products.

But can the skin absorb these ingredients and benefit from them-or is it a marketing gimmick to get us to spend money? 

The skin is the largest organ of the body, covering an area of up to 2 square meters and weighing up to 3.6 kg in an adult. It consists of three layers, but the first two layers are the most interesting for skincare manufacturers.

The outermost layer, the epidermis, is the one we can see and touch. 

"It's made up of cells called corneocytes that act like bricks. These bricks are held together like cement by fats such as ceramides, cholesterol, and fatty acids," explains cosmetic chemist Ron Robinson, founder of the skincare brand BeautyStat

The middle layer of the skin is the dermis, which makes up 90% of the skin's thickness.

"All the most interesting things happen there. It consists of connective tissue, blood vessels, hair follicles and sebaceous glands, as well as collagen and elastin. These are the magic proteins that we need to keep our skin smooth, to avoid wrinkles, and this is what makes our skin firm - it's like the holy grail of anti-aging," says Mary Sommerlad, a consultant dermatologist in London.

According to Greg Altman, founder of Evolved by Nature, "most biomolecules never penetrate the skin barrier. This is because the skin is our body's first line of defense against the outside world.

"The skin is designed to protect, and it does this very well. It regulates temperature and water balance, protects against disease, and maintains the microbiome balance of healthy organisms. The skin does so many vital things that it has to be a barrier. It can't be a structure that's easy to penetrate," says Zoe Draelos, a dermatologist at Duke University in North Carolina who has been working in the field for over 35 years.

According to a cosmetic chemist, the molecules of ingredients such as oils, silicones and waxes, which are often used in moisturizing products, are too large to penetrate the epidermis. They are trapped on the surface of the skin, where they retain moisture inside, keeping the skin soft and smooth.

In order for a molecule to penetrate the epidermis and reach the dermis, it must meet certain criteria: be lipophilic (fat-loving), have a slightly acidic pH of 4.6 to 5.5, and a molecular weight not exceeding 500 Dalton.

However, there are methods to circumvent these barriers. Cosmetic companies can break down large molecules into nanoparticles or encapsulate hydrophilic compounds in layers of fat or oil. Another option is to use microneedles to create microscopic holes in the skin or apply chemicals, such as glycolic acid, that increase skin permeability.

Finally, there are ingredients that can penetrate the skin. For example, retinol can pass through the lower layer of epidermal cells, which protects against UV radiation, while inhibiting their growth and increasing sensitivity to sun exposure.

As for parabens, used as preservatives and anti-pollution agents, there are studies that hint at their potential impact on hormonal balance. However, according to dermatologist Mary Sommerlad, there is no definitive proof of this, and dermatologists generally consider these ingredients safe, although pregnant women are advised to avoid them as a precaution.

How and what does our skin absorb

Vitamin C

Pure vitamin C usually cannot penetrate the outer layer of the skin and tends to degrade quickly when incorporated into creams or serums. However, there are numerous "derivatives" of vitamin C, some of which are more stable and able to penetrate deeper into the skin.

Peptides

Some peptides are able to penetrate deep into the skin, although they are very diverse. The possibility of increasing their penetration can be achieved by modifying their molecular structure or combining them with other peptides.

Retinol

Retinol doesn't normally penetrate deep into the skin, but its penetration ability can improve depending on what it is combined with. In an experiment conducted by Unilever, it was found that when retinol is combined with oleic acid, a fat also found in olive oil, it significantly improves its penetration through the skin.

Vitamin E

There is some evidence that vitamin E can penetrate the skin and reach its deeper layers. However, similar to vitamin C, vitamin E is prone to decomposition from exposure to air and light. Therefore, to be effective, it must be reformulated into a more stable, oxidation-resistant form.

Altman notes that "skincare is at the intersection of science and marketing," pointing out that the beauty industry is largely self-regulating. He also emphasizes that science still has a lot to learn about the skin's ability to absorb ingredients, the depth of their penetration, and the possible risks of these processes.

"Although it is well known that various skin care products can have a positive effect on skin health, the exact mechanisms underlying these effects are not fully understood," says Sebastian Bjorklund, associate professor of physical chemistry at Malmö University in Sweden.

According to Sommerlad, developing ingredients that can penetrate the dermis and beyond is actually very difficult.

"Not many drugs can easily overcome the transepidermal pathway because the chemical process behind it is quite complex," she explains.

One of the reasons why transdermal vitamin patches have not become widely popular is that they have not been widely distributed. Similar patches that stick to the skin have long been used to deliver nicotine, fentanyl painkillers, and pregnancy-preventing hormones, providing people with a convenient way to take the medications they need on a regular basis.

Inspired by this success, in 2003, the U.S. Army Research and Engineering Program began developing a project that explored the possibility of using similar patches to deliver vitamins and minerals to soldiers during combat.

However, even after two decades, scientific evidence supporting the effectiveness of such patches remains limited. The results of the US military's research have not been made public, and large-scale clinical trials have not been conducted. A small study in 2019 found that gastric bypass patients who used multivitamin patches within a year of surgery had twice the risk of vitamin D deficiency and lower levels of vitamins B2, B12, folic acid, and ferritin compared to those who took vitamins in tablets.

"Vitamins are much more efficiently absorbed from the inside. Topical administration through the skin is not a substitute," says Draelos.

She says that in addition to maintaining a healthy, well-balanced diet, you need to consume plenty of water. "In order for your body to produce the vitamins, minerals, fats, and proteins that are naturally found in the skin, you need building blocks," she says.

So, which skin care products should you choose? Dermatologists Draelos and Sommerlad recommend the following:

• if your skin is healthy, choose a mild cleanser and an effective moisturizer that are suitable for your skin type; 
• use sunscreen, preferably with vitamin C or other antioxidants; 
  
• Follow the principle of "less is more" by using products with a limited number of ingredients, especially if you have sensitive skin.
  

"Another piece of advice I give my patients is to treat their skin like a silk scarf. You wouldn't scratch, pull, or pinch a silk scarf - it would ruin it. It's the same with your skin," says Dr. Draelos.

For those who want to reduce the signs of skin aging, Sommerlad recommends using retinoids, as they can help increase collagen and elastin levels. 

She also advises to consult a dermatologist, emphasizing that this is a real minefield, and we certainly don't want to spend significant amounts of money on products that can either damage your skin barrier or not bring the desired results.

 Despite everything, experts agree that healthy skin is capable of taking care of itself.

"A lot of people think that you have to do something to your skin to make it healthy or to make it look good, but in reality, the skin will be beautiful as long as it's healthy on its own. So in a way, the less you do, the better," concluded Draelos.

Recall 

With the onset of spring, dermatologist Ksenia Konovtseva advises to use sunscreen daily to protect the skin from the harmful effects of UV rays, hyperpigmentation, and skin cancer, to choose products according to the type and needs of the skin, and to take additional protective measures, such as wearing sunglasses and hats.