The science of skin treatment

Lisa Burke takes a look at how the body's largest organ works and what can damage it, then investigates the effectiveness of moisturisers, vitamins, sunscreens and more.

I cast my eye along my bathroom shelf: "PurCellin Oil", "fluide hydrant quotidien", "Ionzyme", "Iceland moss", "puff-draining peptide balm", "pressocapsular-firm-system detoxyboost"…

Glossy bottles and scientific-sounding terms are employed to lure us into the hope that these wonder creams will work. But turn to the back to find the real ingredients. Even with a couple of chemistry degrees, I don't know what they do for my skin. This unknown breeds scepticism in me.

I am not alone. Ask most women what their skin cream does and they will tell you they hope it works. But they have no idea how it works or what they should be looking for in a skin cream.

More than a thousand years ago, one of the greatest medieval surgeons, Abu Al-Qssum Al-Zahrawi (936-1013), wrote a medical encyclopedia, Al-Tasrif , including a volume on the medicine of beauty, Adwiyat al-Zinah.

Hop along a few hundred years and you find Elizabethan women using a toxic mix of lead and vinegar to create the Mask of Youth, a pale white face. It was anything but youth preserving as it led to rotting teeth, disfigured skin and could eventually kill you, as it probably did Queen Elizabeth I.

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Nowadays, we like to think we know more. Our skin ideal is flawless and ageless, and we enlist the help of scientists all over the world to achieve it. Huge research and development teams are dedicated to the billion-dollar cause. Dr Yuliya Zeilinski, the global director of medical management for Beiersdorf (the skincare company based in Hamburg, Germany, that makes Nivea, Eucerin and La Prairie), smiles as she says: "Beiersdorf refer to research and development as their expensive hobby. We like to go the serious and technical way, to be good and safe".

According to Dr Maria Angelo-Khattar, the managing director and founder of Aesthetica Clinic in Dubai, "approximately 20 per cent of our skin's condition is determined by our genes and 80 per cent is due to the influence of the environment". Hooray! There is hope. Although I dread to think what damage I have already inflicted upon my skin. Is it reversible? How can I now protect it?

Skin is our living shield, the largest organ of the body, accounting for 14 per cent of our weight. When we eat, our clever bodies prioritise vitamins and minerals for essential organs such as the heart, lungs, liver and brain. If we are malnourished, fat or thin, our skin suffers. Skin can also show illnesses such as diabetes and heart disease.

Water makes up 70 per cent of us and our skin. Every cell of our body needs water to transmit nutrients. It makes our skin look plump.

Protein (which makes up 25 per cent of our skin) gives skin strength. Lipids (2 per cent of our skin) hold in the moisture. If the skin has fatty molecules between the cells of the upper layers, then there is a greater chance of water being retained.

Moisturisers act in a similar way, creating another barrier layer of fatty (lipid) molecules that seal the skin's surface to prevent water evaporating. They sit on the top thin layer of skin, the epidermis.

"Moisturisers are essential because, with UV protection, moisturising the skin is the first anti-ageing action," says Professor Frédéric Bonté, the director of research at Guerlain. It is best to apply moisturiser to damp skin so that you trap more moisture into the epidermis.

To increase water, or anything else, within the dermis is difficult because the molecules have to be small enough to penetrate what is called the dermal-epidermal junction (DEJ).

Huge molecules (such as collagen, elastin and hyaluronan) if present in a cream will "fill the cracks", just like a good moisturiser, but they cannot move through the DEJ. So basically they can help your skin on the surface, but they do little or no lasting good.

To penetrate the surface you need to look out for products with vitamin A (often labelled as Retinoic Acid, Retin-A and Retenoids).

"Vitamin A has been used for 40 years and is considered indispensable in our arsenal of anti-ageing products," says Angelo-Khattar. "It works by promoting the turnover of surface skin cells, making way for new cell growth underneath."

Remember, though, that Retin-A is a drug, not a cosmetic, and can have side effects. It makes skin more susceptible to sun and can cause birth defects in pregnant women. You would need to visit a dermatologist to get a prescription for Retin-A. More diluted versions are available over the counter. For example: Skinceuticals Retinol 1.0 and La Roche-Posay Biomedic Retinol 60.

Vitamin C (often listed on cosmetics as L-ascorbic acid or ascorbyl) stimulates the skin's fibroblasts, which increases collagen production and helps skin repair itself. But it is not good at penetrating the skin's layers and also does not last long once exposed to light. Thus many products with vitamin C come in dark-coloured bottles for a longer shelf life. As our bodies cannot store the vitamin, neither can our skin.

In the war on wrinkles, our greatest enemy is the sun. UV radiation comes in two forms, A and B. UV-B light can damage DNA directly and UV-A light creates free radicals, which can damage DNA indirectly.

Cells with damaged DNA are potentially cancerous. The body goes into protection mode and tells the cells to self-destruct. But some don't, and just shut down. As we age, the number of such cells increases. Worse still, they can release enzymes that destroy collagen, which is already reduced as we age.

The sun's ageing effects are obvious. "Look at your forearms and compare the inner and dorsal sides," says Dr Thomas Berger of the German Medical Centre in Abu Dhabi. "You see the same genes, the difference is only the sun. Best cream: sunscreen!"

So, am I still a sceptic?

Of the science, no. I believe some fascinating and thorough science is behind many skincare products. But I am conscious of what we do not know. We chisel away at understanding how our complicated bodies work... while they continue to work.

"Anti-ageing" is a clever phrase dreamt up by some marketing whiz. It has taken me a long time to realise that such products have no hope of making me look younger; they can only reduce the probability of my looking older in the future.

So I'll continue to read the labels with a healthy pinch of NaCl (sodium chloride - better known as salt).

Why antioxidants really do work

"Antioxidants" has been a buzzword of the beauty (and food) industry for some time. To get an idea of what it is, try this simple experiment: cut an apple in half, leave one side exposed to the air, and squeeze lemon juice over the other side. After about 15 minutes you will see the side without lemon juice turn brown. This is oxidation. The lemon acts like an antioxidant on the other side of the apple, which stays fresher for longer. The idea is to use skin products that protect against oxidants.

"Oxidation is a natural process necessary in many physiological reactions, resulting from natural use of oxygen, which is unavoidable because if there is no oxygen there is no life," says Professor Frédéric Bonté, the director of research at Guerlain. We live in an atmosphere of oxygen. Why the need for antioxidants? "Antioxidants quench free radicals and fight oxidation," says Bonté.

Electrons like to hang around in pairs. Free radicals have "unpaired" (single) electrons dangling on the end, which makes them unstable and highly reactive; that is, damaging. Antioxidants mop up free radicals, chomp them up like Pac-Men. The body produces its own antioxidants but stress, the sun and growing old means we need more help. So drink more green tea, and look out for antioxidants in your face creams.

Top anti-ageing ingredients to look for in your skin creams


A vitamin A derivative that work by rapidly turning over cells, which results in healthier and younger-looking skin.

Green Tea

A powerful antioxidant that neutralises free radicals. Drink it and apply it topically (via a cream, don't bathe in it!).

Glycolic Acid or AHA

A fruit derivative that exfoliates the top layer of your skin, exposing the smoother layer beneath.

Vitamin C

An indispensable ally in the fight against free radicals.

Hyalauronic Acid

Your best weapon against dry skin, most effective when injected into the dermis.


An extremely effective repairer that promotes cell turnover.


You need to invest in a factor-50 that protects against UVA and UVB rays. It will not be enough to buy a face cream with sunscreen in it. Apply after your daily routine and leave to sink in for a few minutes before applying make-up.