Are hair dryers good or bad for your hair? And what about natural air drying of hair? Today we talk about the results of a Korean study, published in the Annals of Dermatology magazine, which tried to understand what is best to do to preserve the beauty of the hair when it comes to drying it and the results are truly amazing. But let's go in order and try to understand what the research says (Lee et al, Ann Dermatol, 2011).
External factors that can weaken the hair
The shaft of our hair can easily be damaged by various external causes. For example, treatments such as perming, dyeing or bleaching hair, especially if performed frequently, can damage our hair. But a danger to the beauty and health of the hair is also represented by friction, which weakens the very structure of the hair, such as when we rub the hair with a towel or brush it vigorously when wet, increasing the risk of breaking the hair shaft. Even the sun with its UV rays poses a risk to hair, which can weaken, become too dry and lose its shine. Finally, even the simplest operation that we subject our hair to every day or several times a week, such as washing the hair with shampoo and then drying it, can damage the hair. Many argue that it is better to let your hair dry in the air and avoid the hair dryer, but is it really so? The study we are discussing today offers an answer.
Can a hair dryer be better than air drying? The study
The study was carried out in the laboratory on samples of hair about 20 cm long and not chemically treated. Scientists have recreated the conditions you would normally experience when you wash your hair at home. So, first the hair was washed with shampoo, rinsed and then dried in different ways. A part of the hair was dried in the air, at a temperature of 20° C, another part with a hair dryer, activated for 60 seconds and placed at a distance of 15 cm, another part again with a hair dryer, but this time operated for 30 seconds and at a distance of 10 cm, and finally the last group of hair was dried with a hair dryer operated for 15 seconds and at a distance of 5 cm. The hair dryer has been used with constant motion, just as you would in a normal drying operation. Analyzing the color of the hair, its degree of hydration and its structure, this is what emerged. Using the hair dryer at a distance of 15 centimeters and moving it continuously caused less damage than all the other systems, including air drying, which was still safer than using the hair dryer at closer distances, which is equivalent to exposing the hair at higher temperatures. It has always been thought that letting the hair dry in the air is the safest and most respectful way for the hair. Instead, research has shown that the wetter the hair stays, as happens with natural air drying, the more likely it is that its color will be altered and that the cortex of the hair, the layer just below the cuticle, can swell and break, weakening the hair and increasing the risk of split ends.
The study therefore states that using the hair dryer keeping it at a distance of at least 15 centimeters from the hair and moving it continuously is the best way to dry wet hair, respecting it at the same time. Immediately after, in terms of hair health, comes natural air drying, which is less harmful than a hair dryer used too closely but in the long run, as we have seen, can weaken the hair.