Saturday, 20 July 2013

How to think like a scientist when analysing claims made about beauty products

It can be bloody hard wading through claims about beauty products made by both people within the beauty industry or even by the general public. If you frequent forums regularly you will be constantly bombarded by people making statements about products or ingredient, claiming them as facts, when often they are just perpetuating rumours and falsities. Here are a few tips that I use to navigate my way through and come to my own truth:

  • Question everything - it was part of my scientific training that every statement had to be proven to be true. So, when I was reviewing the literature for my research I had to search both for articles that supported my point of view but also look for articles that were in disagreement. I then had to examine both and work out which was more likely, usually based on the size of the study. How to apply this tip: if someone makes a statement don't just blindly believe it - have a quick Google and see what sort of websites support that point of view and what ones are against it. I find this most useful for backing up statements that I read in forums as I find that often people are unwittingly spreading untruths (ie they genuinely believe what they are saying but they too have been mislead). For example, I once replied to a question on a forum from someone asking what are the best face wipes to use - I said that I just use baby wipes as they are cheaper and come in massive packets. Someone then responded saying that baby wipes are one of the worst things you can use on your face - that the ingredients in them are shocking. I was a tad concerned because, if it is shocking for our face, surely that mean it was bad for baby too? Especially when I would use 1000 a day on them. I did my own research and sure enough, there was nothing bad in them but once again someone was perpetuating a false rumour.
  • Be wary of highly emotive language - as soon as I start to read an opinion that is very forceful, my suspicious goggles come down. I have seen websites claim that certain ingredients WILL cause cancer, and that you are slowly killing yourself/your family and that they MUST be avoided at all costs. In science we are rarely that certain unless something has been absolutely conclusively proven - our statements would say 'there is an association between the use of certain ingredients and the development of cancer' or 'exposure to certain ingredients may increase the risk of developing cancer'. Science uses a very passive language so as soon as I read these highly emotive statements I get suspicious why someone will be making them - what they have to gain from making these statements, which leads to the next point: 
  • Question the motives of the information source - I notice that there is a lot of scare mongering in the beauty industry about certain ingredients - this usually comes from the natural companies scaring people off 'harmful' ingredients. The classic example is parabens. There has been only one scientific study showing an association with parabens and breast cancer and a myriad of studies showing no association at all. The one study only had a small sample size (see below why this is important) and no one else has ever been able to replicate their results, yet it is now 'common knowledge' that parabans are bad. If someone is trying to scare you off certain ingredients ask yourself 'what is their motive?' - are they trying to sell you their products? One day I hope to write a post on 'harmful' ingredients and whether they really need to be avoided.
  • Look at the sample size - if a company has claimed that it has done research they usually say how many people they did the research on - if it is less than 20 the study is pretty much useless. Even less than 100 is not particularly impressive. When you do a scientific study you have to statistically calculate how many subjects (ie the sample size) are going to be in the study for it to have any statistical relevance. This is called a power calculation. There is no magical number that determines how many subjects should be in a study but in something like skincare there are so many variables that need to be taken into consideration - age, ethnicity, skin type, pre-existing conditions etc. All of these can affect the results. Therefore, you need many many people in a study to account for all of these variables. When you see company's using over 1000 subjects, that is a very respectable sample size.
  • Look at how the study was conducted - 
    • was it just an interview (ie 12 women were interviewed and said that they noticed a reduction in their wrinkles), if so that doesn't really hold much cred with me. I'm sorry but I don't trust peoples own opinions. If you start seeing percentages quoted then that means some sort of analysis has been done ie there was a 25% reduction in wrinkles over a 4 week period - it is likely that they have used software to either count the number of wrinkles or the depth of wrinkles or something like that. Again, you want a decent sample size for these results to hold any true relevance. 
    • If you see the words in vitro as in 'in an in vitro study our magic ingredient was found to cause skin cells to regenerate 20% faster' this means that the research was conducted in a petri dish in a lab and not on actual patients. Absolutely nothing wrong with that as that is how a lot of scientific experiments are conducted. Just be aware that just because the magic ingredient works on skin cells in a petri dish doesn't necessarily mean that it will work on the skin.
    • If you see the words in vivo then that means that it was conducted in/on a person (or animal). To be honest, I haven't really seen this phrase used within the beauty industry. 
  • Just because an ingredient is an irritant doesn't mean you need to avoid it - this statement more applied to people with normal skin. If you have sensitive skin you need to tread carefully. You often hear that products are now this or that free, that a certain nasty ingredient has been removed. A good example is SLS, the foaming agent in shampoo. Yes, there is a proportion of the population that react to this ingredient - you will know if you react if you get itchy skin or scalp after shampooing with a product contain SLS - but the vast majority don't. If you have never reacted to it before, then there is no need for you to start avoiding it just because some people are purporting it as a nasty. However, if you do have very sensitive skin then you are best off going back to the basics then slowly introducing products one at a time to determine exactly what it is that you are sensitive to.
  • Just because an ingredient is natural, doesn't ensure that it is harmless - nature has some pretty potent irritants out there or worse there are some highly poisonous plants. Therefore, you can't assume that just because a company claims that it's product is 100% natural or 90% or whatever that it is more gentle than a product not claiming to be natural. We can all react to different things. I am allergic to orange blossom. It doesn't affect my skin but makes me sneeze like a maniac. Therefore, I could never use Lush's Gorgeous moisturiser because orange blossom is a key ingredient. I tried it and it did leave my skin looking great but turned me into a sneezing snotty, red eyed monster...not the look I was trying to achieve. The reverse statement is also true - just because an ingredient is a man made chemical doesn't mean that it is harmful. If anything, these chemicals have been more rigorously tested to ensure their safety, than some of the natural ingredients. 
  • Ingredients are often only harmful at certain concentrations - there might be info out that ingredient X is harmful or carcinogenic or an irritant but there is usually a certain concentration that it needs to be at before it causes any harm. For example, one cigarette is unlikely to cause lung cancer but if you smoke 3 packs a day for 30 years then your chance of getting lung cancer is huge. Another example is sodium chloride (NaCl - better known as table salt). In my science lab we had to store all of the chemicals we used in certain locations based on how dangerous they were. We had a special metal cupboard for the acids, a similar one for the teratogen (chemicals that can cause birth defects) and any chemical that was a potential carcinogen (cancer causer) had to be labelled with such info to alert the user so that they knew that they had to always wear a face mask and gloves when handling it. NaCl was considered a teratogen. This surprised me as it was an ingredient that I used daily in my cooking and here it was in my lab considered a teratogen. At very high concentrations, NaCl can interupt with pregnancy, hence it's teratogen status yet it is completely harmless at low concentrations. The same goes for ingredients in beauty products - they may only be harmful at quantities far in excess that you would ever become exposed to simply by using the product (ie you would have to slather yourself in 5L of the product every day to become exposed to harmful levels when in reality you would be using less than 1ml). 
These are just a couple of tips to help you navigate your way through all the information that we are constantly bombarded with. Google is my best friend when trying to find out more info on a product or ingredient, but my number one rule is to never just read info from one site - have a look at at least three different sources before coming to any conclusions. Remember - any idiot can post whatever they like on the internet so always try to cross check your facts. 

What are your tips to get through the minefield of information out there?