Does stress make your hair go grey?

People often say that grey hairs are the result of stress. But is that true, or is it just a myth? After all, bouts of ill-health do write patterns into some parts of the body that grow. Fingernails, for instance, can develop temporary ridges called Beau’s lines that capture the timing of when an illness occurred. So, speaking with Chris Smith, Martin Picard at Columbia University, explains that he wanted to know whether hair - and specifically hair colour - does the same thing…

Martin - What we had to do first was to develop an approach where we could take someone's hair and then put it on a scanner. And then we digitized the hair into a string of numbers of how dark along the hair and the naked eye can see kind of a continuous colour across a general hair. But when you start to look at hair with such a level of resolution and precision, you see there's actually a pattern, subtle changes in the colour of the hair. And that's what we were able to quantify and then use to look at connections with stress and other things.

Chris - Because hairs grow continuously, you're therefore capturing a timeline. It's a colour equivalent of tree rings!

Martin - Exactly. The tree ring analogy is a beautiful one. You can basically get a record of someone's biological history and that's fascinating because there is no other thing in the human body that allows you quite this kind of perspective. Across time, we all walk around with our biological history attached to our head.

Chris - And can you actually marry up those colours to life events? So someone says: "I had a really stressful time last week, I had a maths test." Can you see that reflected in the colour of the hair?

Martin - We found examples of this. And we had a participant who gave a hair and her hair was dark at the tip. And then it turned white in the middle and then turned back to dark near the root. So then if you start at the tip, which is the oldest part of the hair, dark then white and then dark again. So then we wondered what happened. And because we know hairs grow at about one centimeter per month, and that hair in particular, the white segment was two centimeters. So we thought something that lasted about two months must've happened and without seeing her hair without seeing the hair pigmentation pattern that we produced, she recorded her life events, you know, over the past year. And she had just graduated, defended her PhD thesis and then went through some very stressful, personal relationship issue and then moved across the country and so on. And then that whole stress lasted about two months. And then her stress level went back down to normal. And we saw that aligning almost perfectly with the colour pattern in the hair.

Chris - Can you do this in people who are not on the verge of going grey though? Because there are lots of people who have stress, but their hairs don't go white like that. Do the colours subtly change nevertheless so you could still use this as a marker of stress?

Martin - Yeah, that is a great question. We think so. This study that was just published focused really on events of grain. It concerned to people, you know, anywhere from early twenties to late forties, fifties, where there are some hairs that are in the process of going grey. The youngest participant in our study was a nine year old girl. She had kind of a spontaneous, rare, white hair. We think it's probably more generalisable than, you know, just old people or just people that are accumulating a lot of white hairs. But perhaps just in the non-grain changes in the hair colour, we might be able to do glimpse and to decode past events of someone's biology and psychology. So that we're very excited about pursuing this further.

Chris - How do you standardise it though? Because what might be greatly traumatic for the person that you spoke about with her thesis and then personal problems and so on, someone else who's perhaps more resilient might not find that stressful at all, or might find it stressful, but not to the same degree. So how do you standardize for the individuals when you're using a tool like this?

Martin - This is a great problem in the field of psychology and behavioral sciences. What matters most? Is it what the person reports and says, this was a 10 out of 10, most stressful thing in my life, or, you know, could it be some biological marker of stress? And our studies assess both and we think both are relevant and there's actually quite a bit of data that what matters most is what the person perceives.

Chris - And how do you think that that perception of stress is translated into a change in the colour of her hair?

Martin - If we understood this, how psychological states make their way into our biology, that would be a tremendous advance for medicine. That is one of the biggest questions, I think, at this point in psychobiology, and maybe across the biomedical sciences. There's not so much known about this, but there's a few hints, including stress hormones, and those hormones evolved over millions, billions of years to help prepare the body for an eventual fight or flight response. And those hormones can have very profound biological effects on the energy within cells and on gene expression. So that's one way in which subjective experiences can be translated into biological and molecular changes in ourselves, including the hair cells.

Chris - Apart from obviously giving us an insight into something that was folklore: "This sent me grey, when I went through that!", does this also offer us therefore some kind of monitoring tool going forward for medicine, for psychology, really, to, to get some kind of life course in people and marry up the impact of distress and stress on people's health?

Martin - I think that would be beautiful. And maybe we can imagine a time in the future where you go to your doctor, you get a few hairs plucked, and then the report that comes back, you get a time course, like a little graph with a wiggling line, right? With ups and downs. And from this report, maybe your doctor could say, "Ooh, it looks like six weeks ago something happened, you know, that changed your biology, what was that?" And then maybe you could say, "Oh yes, you know, I got into this relationship. It's been very stressful or, you know, I started this new job" and maybe that might be a way to help think and be mindful of the things that we expose ourselves to and maybe a tool to direct, positive and useful changes in our lives.