The type of fatty acids we eat and put on our skin seem to make a huge difference to the way our skin looks and feels. A few years ago, after a lot of research on the subject, I drastically reduced the proportion of unsaturated fats in my diet. (A decision my GP might have well frowned on!) The results were spectacular. Only five days into the new diet my skin returned to being normal after years of being dry. It was like getting back the skin I used to have in my twenties – a little miracle! A couple of months later I noticed my sun spots were fading – I used to have a serious skin pigmentation problem that make-up could no longer hide and no cream (however expensive) seemed to alleviate. A year later the sunspots faded to the point they became unnoticeable. These days I am comfortable going out without wearing foundation at all. And it gets even better: my skin has regain suppleness and my wrinkles have diminished – I really did turn back the clock and it all comes down to the fats I eat.

Every skin expert would tell you that fats are hugely important to the integrity and function of our skin:

• The outer layer of our epidermis, which protects the skin against external influences is often compared to a brick wall in which dead, keratinised skin cells are embedded in a matrix of inter-cellular lipids in the same way bricks are embedded in mortar. This lipid matrix is responsible for keeping skin moisturised.
• Deeper in the skin, fatty acids are essential components of living cells membranes, playing an important part in regulating membrane fluidity. They are also calorie-rich nutrients that living cells convert into energy.

Not all fats are created equal. There is an amazing variety of fatty acids (building blocks of fats) from tiny molecules with only four carbon atoms in their chain to mega-molecules with chain lengths of over thirty carbon atoms. Some fats have stable molecular structure – the saturated fats. Others, the unsaturated fats, are less stable and they will behave very differently once absorbed into our bodies.

Saturated vs. unsaturated fatty acids
We a hear a lot about saturated and unsaturated fats these days. Many doctors believe unsaturated fats are better for us because they lower blood cholesterol and shield us from cardiovascular disease. But the scientific world is not so united in the belief that unsaturated fats are all good and wonderful. Dig a bit deeper and you’ll find experts warning that an excess of unsaturated fats, especially the polyunsaturated ones with their unstable molecules, cause cellular damage – they trigger free radical chain reactions that alter vital cellular structures, thus accelerating ageing processes and even causing abnormal tissue growth and cancers.

Fatty acid chain lengths
A less known classification of fatty acids is by molecular size.  There are short chain, medium chain, long chain and very long chain fatty acids. The chain length makes a big difference to the speed at which fats are absorbed into cells and turned into energy. Short and medium chain fatty acids – like those found in coconut oil, palm oil and cocoa butter are so quickly absorbed and processed by cells they are almost instant energy. That is why they are sometimes called de-fatting fats – they speed up cellular metabolism and prompt cells to burn other fats a lot faster.

So how do different types of fatty acids influence the skin?

Saturated vs. unsaturated fatty acids in skin care products
The wide majority of moisturisers aim to put some fats into our skin in order to replenish its lipid barrier. Since skin is so exposed to environmental factors – especially UV radiation – any unsaturated fats are prone to oxidate very fast. Even before doctors and nutritionists settle the saturated vs. unsaturated fats debate and come up with the optimum balance for our diet, I believe it is safer to limit the amount of unsaturated fats in skin moisturisers, especially in day creams.
Cosmetic formulators know that unsaturated fatty acids, especially the polyunsaturated ones increase membrane fluidity and bind water into the skin. But you can have too much of a good thing.  If membranes are too fluid they will become unable to keep their content. Water will leak out and the skin will become dry as a result. Which, by the way, is not a bad thing for cosmetic companies, because that will make you reapply their products more often. I take a different view – that a cosmetic product should help the skin retain moisture naturally and that cell membrane fluidity should stay at an optimum level, not be increased at any cost.

Fatty acid chain length and skin care
The size of a fat’s molecule will determine how quickly that fat penetrates the skin. Short and medium chain fatty acids will give a boost to cellular metabolism, prompting cells to generate more energy faster and giving skin that lovely, healthy glow. Longer chain fatty acids will give a richer feel and help alleviate skin dryness.

Fats really are wonderful things!  There is such a diversity of fat types, each with different properties to benefit different skin types – from oily to dry and from teenage to mature skin.