Transepidermal Water Loss (TEWL) refers to the natural evaporation of water from your skin. TEWL (pronounced “tool”) is most obvious when we sweat, but it’s a natural process that our body carries out 24/7….even when we sleep.
When your TEWL is too high, your skin can dry out and become vulnerable to skin diseases such as eczema, dermatitis, psoriasis and keratosis. This is because people with TEWL have a weakened epidermis (the outermost layer of skin). Genetic science has recently isolated a gene that plays a role in our TEWL. You can find out if you have this trait by using Genomelike. This is a huge help those who suffer from – or hope to avoid – dry skin and all problems that can come with it.
If you have skin that is constantly dry – no matter how much moisturizer you apply – your TEWL is high. TEWL is something that dermatologists and beauticians are well aware of (note the vast array of moisturizing beauty products on the market). But TEWL is not limited to the face – dry skin can occur anywhere on your body.
Are you wondering if you have the genetic trait for high TEWL? Certainly, knowing that you have a genetic propensity for any specific trait gives you the ability to take measures to avoid it.
There tends to be variation in TEWL among ethno-geographic groups. (This is one of the ways that genetic scientists first deduced that DNA plays a role in TEWL.) You can read this study and see if any of the findings might pertain to you. There is also interplay with other genes. For example, we know that heart rate during exercise varies partly due to genetics. And of course, your TEWL is highest when you break a sweat. The point is this: not only have geneticists identified a gene responsible for TEWL, but the body of information about genetics is growing at an astounding rate. Knowing what your own DNA holds will be increasingly important to maintaining optimal health.
No. Like most genetic traits, environment plays a role. The question is: how much do environmental factors “trigger” TEWL? The amount of moisture released from our body can be affected by environmental factors, such as temperature, seasonal variation, sun exposure, and smoking. There’s also humidity, diet, exercise, and myriad other factors. If you have a propensity for TEWL, you might – for example – think twice about living in Phoenix, Arizona. The ultra-dry desert climate, combined with constant air conditioning, can suck the moisture right out of your skin. (At the very least, you’d want a humidifier in your home, because A/C removes a lot of the moisture from the air.)
Fun fact: the skin is the largest organ in the body. And TEWL isn’t limited tohumans – all terrestrial animals have some form of TEWL.
TEWL is a function of the body’s regulation of moisture in the epidermis to maintain healthy skin. This layer of skin performs a vital task: providing a protective barrier for your body. What happens when you cut open your skin? Your body works overtime to repair the “breach”. Without the skin, the body is vulnerable to every type of pathogen under the sun.
The more specific – and palpable – example of TEWL is the cooling effect of perspiration, a.k.a sweat. Your body makes use of a neat trick of chemistry: when a water molecule evaporates, an endothermic reaction (heat-absorbing) takes place. Wind can further cool you down because it accelerates the evaporation of water from your skin.
If you know have a genetic propensity to TWDS, there are dozens of measures you can take – starting with a humidifier, moisturizers, and a healthy diet. This next suggestion probably won’t come as a surprise: If you are currently suffering from high TEWL, your best option is to see a dermatologist. TEWL is part of what they deal with every single day. The Internet can be a good place to educate yourself and find suggestions for treatments. Beware of manufacturers of beauty products who make extravagant promises as they try to sell you their own cosmetic snake oil. Better to trust the un-biased opinion of licensed dermatologists.
Yes. Your DNA results can help you determine if you have the trait for high TEWL.
This doesn’t mean that you definitely will have high TEWL. It also does not mean that those without the gene will never suffer from dry skin. What it does provide is the best available information to take the best care of your skin. All you have to do is have your DNA sequenced by companies like ancestry and 23andme and upload your DNA to Genomelink to find out about dozens of traits nested in your DNA.