Our hair is amazing. We have so much of it for a start (well most of us!). Every scalp contains up to 150,000 hairs all growing steadily at a rate of about 1cm a month. That means we are churning out over 10 miles of the stuff every year!
And it's strong too. Each hair can support about 100g; a whole head full, about the weight of two elephants (2 tonnes). Although it's not clear who tested that one.
Actually in terms of strength it's quite unique. It's very bendable – allowing us to move it around and style it more or less as we please. But it's not extendable – you can't pull it and make it longer. So although it's actually as strong as steel, a better analogy is Kevlar – light, flexible, but very tough. You could probably make a bullet proof vest out of human hair!
But for every strength, there’s a weakness and for hair it's becoming brittle. Dry your hair out too much and like a tree’s branch, it will snap. At its core, the flexibility and suppleness of hair is a result of its moisture and the proteins (the natural scaffold) that make up the hair itself.
So not surprisingly, things that reduce moisture, or affect the healthiness of the hair’s proteins will lead to dry brittle hair.
Let's start with diet. People who don't eat enough or don't eat a balanced diet rich in proteins, vitamins and minerals, will have dry hair. People with anorexia for example always have terrible hair. In fact much of it will drop out. A balanced diet, including collagen, vitamin C, B vitamins such as biotin (vitamin B7) and Niacin (vitamin B3) have all been shown to be essential for healthy hair.
Next, there’s moisture. Too much sun, too many washes with strong shampoos, chemical treatments, too much blow drying - they all drain away the water and hence the suppleness giving you dry hair that easily snaps.. Treat your hair with respect, don't abuse it!
Lastly, hormones play a role too. These regulate the oils that spread over the scalp and thus play an important part in keeping hair healthy. The thyroid gland is very important here – an overactive thyroid will produce very dry hair very quickly.
So to keep your crowning glory shining and healthy, … remember to eat but not to heat!
Dr. Martin Godfrey