For the truth you have to go further than skin deep

Debunking some of the ‘facts’ you thought you knew about your skin and how to care for it

SKIN is our largest organ and something we may take for granted when it’s healthy. Here are some of the most common myths about the skin, and some truths you can rely on.

Skin constantly renews itself

TRUE The skin provides a dynamic barrier between your body’s internal environment and the outside world. Cells called keratinocytes in the epidermis (the outer layer of skin) are constantly dividing to produce a supply of cells that move up through this layer and are shed from its surface.

Drink two litres of water a day for healthy skin

FALSE The amount of water you drink does not directly affect your skin. Water is supplied to the skin by blood flowing through the dermis, the inner layer of skin; water is lost from the epidermis, especially in dry conditions. The volume you need depends on how much you’re using and losing.

Stress can make skin unhealthy

TRUE Several skin conditions have been shown to be worsened by life events, possibly through stress hormones including cortisol. Examples are alopecia areata, an auto-immune condition where the body’s immunity attacks the hair follicles, causing hair to fall out; psoriasis, another autoimmune condition that causes skin thickening, scaling and inflammation; and eczema, itchy red skin inflammation.

Eating chocolate causes acne

FALSE Acne vulgaris occurs as a result of the interaction between hormonal effects on grease glands in the skin, plus the skin’s immune response to blocked pores and microbes on the skin. Eating a high fat diet is unhealthy, but it doesn’t cause acne.

Washing powder causes eczema

FALSE Eczema is caused by a combination of genetic factors and environmental effects. Soap, detergents and washing powders can irritate the skin and contribute to dryness. Biological washing powders contain enzymes that can irritate sensitive skin and worsen eczema.

Sunshine is good for you

TRUE & FALSE Many people have experienced the feel-good factor of a sunny day, but there are good and bad effects of sunlight. UVB rays are used by skin to manufacture vitamin D which is essential for bone health. Dermatologists use specific wavelengths of UVA and UVB to reduce skin inflammation. But when the skin is exposed to too much UV it can damage the skin cells’ DNA, leading to uncontrolled growth – the basis of cancer. As a simple rule, unless you have a disease or treatment that suppresses your immune system, sunshine is good for you in moderation, but always avoid getting sunburned.

Keep it simple

Wash your skin regularly, but not so much that you remove the essential moisture. Use a moisturiser if your skin feels tight or dry. Avoid stress, eat healthily and drink water when you are thirsty. Finally, protect your skin from too much sun. Sara J Brown

Professor of Molecular & Genetic Dermatology, Wellcome Trust Senior Research Fellow, University of Dundee