Science isn’t just something done by clever people in lab coats. The scientific method – testing, examining the results and establishing patterns and a theory – can be done anywhere. By using the scientific method, we can find out if something is really true. We don’t have to believe hearsay or nod dumbly when a Big Wig tells us and everyone else what is true and what isn’t true because That is What’s Been Written. Instead, we can go away and find out the truth for ourselves.

The scientific method is also a relatively straightforward process. Someone starts by having an idea about how an aspect of the world works. This is their hypothesis (which literally means ‘scene running beneath’). This hypothesis may fly in the face of the accepted theory but that’s okay; if it’s wrong then it won’t be supported by experiment. If it’s right, then it will. To find out if their hypothesis is true, the person conducts several experiments. He or she designs these experiments to show, through physical events, whether or not that hypothesis is correct. Depending on the results, the person may conduct further experiments to make sure that the physical evidence he or she has gathered is proof that the hypothesis is correct and that there wasn’t just a lucky coincidence, which would indicate a possible false correlation. Once false correlations are ruled out by isolating key elements, that person’s hypothesis can be regarded as fact. That’s the whole idea of science.

A painful mouth

I’m describing the Scientific Method because I used it to solve a very mundane problem. I kept getting mouth ulcers. Mouth ulcers aren’t fun. They’re not life-threatening but they can be a real pain. On a regular basis, I’d been getting them since I was eight-years-old, or possibly earlier. About ten years ago, after a particularly bad infestation, I chatted about the problem to a colleague. He said with assured confidence that I was getting them because I was eating acidic foods like tomatoes. I nodded in appreciation at this insight but later on, I thought that my mouth should be perfectly able to eat tomatoes. Evolution would have weeded out such a simple problem. Without any anything else to go on, I was unable to come up with a different hypothesis, so the matter lay dormant.

A year later, I was chatting to friend when she remarked that she bought SLS-free soap for her young son because he’d had eczema problems since he was a baby. That fact got me thinking. I knew that my mouth ulcers are a skin problem of a kind. Could they be the result of my mouth being sensitive to SLS? That idea became my hypothesis.

My next step was to investigate SLS or Sodium Lauryl Sulphate (or Sodium Laureth Sulphate or SLES if it’s the ‘ethyl’ version). It is a foaming agent. If you add a small amount of SLS to a product it makes the product foam up in an attractive manner as soon as you add water. Because of this, SLS is added to soaps, washing-up liquids and toothpaste, among others. It’s present in a lot of products, including toothpaste. It was in the toothpaste I was using. So far, my hypothesis was sound.

My next step was to perform an experiment. I stopped using my SLS toothpaste. I looked for an alternative brand, free of that ingredient. After a bit of effort, I found one in the local health food shop. I began using that toothpaste exclusively instead. After several weeks, I realised that I had not had a single mouth ulcer. It looked as if I had proved my hypothesis.

But this is where a false correlation can take place. Perhaps it was something else in the toothpaste that was giving me mouth ulcers?  To eliminate that possibility, I put some soap, containing SLS, on my fingers and then rubbed my fingers around the inside of my mouth. By doing this, I was isolating SLS from the other toothpaste ingredients. Twenty-four hours later, I had two painful, sensitive mouth ulcers. This experiment gave me the confidence to decide that SLS was the culprit. It’s true that there was still the possibility that some other ingredient was the actual culprit, some ingredient that was in the toothpaste and in the soap, but I wasn’t going to buy a hundred products and deliberately give myself mouth ulcers for two months. There is a limit.

My success at isolating a connection between SLS and mouth ulcers made me think about another skin problem I’d suffered from for years; clammy hands. Did SLS cause that too? That was a trickier challenge because we generally touch more chemical products with our hands than we put inside our mouths. To test this hypothesis, I had to get rid of SLS from all products that touched my hands. This included SLS soaps (which includes pretty much all liquid soaps) and SLS washing up liquids, since I hand-washed my dishes. Eventually, I found an SLS free washing-up liquid made by ‘earth friendly products’. Three weeks after switching to those products, I found that in my home at least, my hands were dry as a bone with almost no outbreaks of clamminess.

One day, soon after, I popped around to chat to a neighbour. He handed me a mug for my tea, fresh from his kitchen draining-board. As I grasped it, my right hand broke out in a sweat. It was that fast! Not only that, but there couldn’t have been much more than a tiny residue of SLS on the mug. Such a large reaction to such a small residue seems to indicate that my hands are hyper-sensitive to the chemical in a similar way to someone with an acute allergy. Since that time, I’ve discovered more chemicals that can trigger clamminess in my hands. One of them is serious air pollution, unfortunately, which is hard to avoid in an urban environment. Nevertheless, knowing what to watch out for is empowering and does reduce the problem.

Some time after I worked out this problem, and blogged about it, an interesting article, entitled Should I try SLS-free toothpaste? appeared on the BBC website. It discussed the very matter of SLS and mouth ulcers. The article reports on a double-bind study that did not find a strong correlation between mouth ulcers and SLS toothpaste. Unfortunately, this could be a deceptive result. Firstly, the study did not factor in a very important element; if you have SLS soap in your bathroom, you’ll be putting SLS into your mouth in small amounts even while using SLS-free toothpaste. I’ve found one has to remove all SLS products from the bathroom and kitchen to stop the mouth-ulcers; it’s that potent a chemical. Secondly, not everyone may be susceptible to SLS. The study would only be useful if it involved people who were susceptible to SLS. Thankfully, the BBC article does conclude by recommending that those with mouth ulcers should try SLS-free toothpaste.

The BBC article also references an earlier article, Are my wash products damaging my skin? which is also very useful, as that article describes the general effect of industrial detergents on our skin. The article’s explanation supports my conclusion that the skin of my hands went clammy when exposed to SLS and other potent industrial chemicals and pollutants.

I do hope people with mouth ulcers and clammy hands hear about this evidence and try themselves to rid their homes of SLS products; those maladies are no fun to have and they can really ruin your day. Funnily enough, there has been a down-side for me after changing to an SLS-free life. Nowadays, because my hands are generally dry in the home, I have to lick my fingers before holding my guitar plectrum. Because I spent so many years playing guitar with damp hands, I can’t get used to playing with dry hands and I have to ‘wet them’ myself to play properly. It’s an issue I am happy to deal with. 🙂