Parabens References and links

Looking at my web traffic I can see that my 8 posts about the safety of parabens has not been a huge hit with readers. I had guessed that would be the case.  In the 4 years I have written this blog I have got an idea of what strikes a chord and I don’t think anyone will be surprised to hear that toxicology isn’t a hot button.   But nonetheless I said what I felt had to be said in the depth to which I wanted to say it.  There is one last piece of the story that I need to post up – I wanted to put on record my sources so anybody who takes issue with my conclusions can see where I got them from.

These are the main documents to which I referred in compiling this article.

In vitro skin permeation and retention of parabens from cosmetic formulations Dene Godfrey Letter to the Editor, International Journal of Cosmetic Science, 2008, 30, 229–230

Concentrations of parabens in human breast tumours P. D. Darbre, A. Aljarrah, W. R. Miller, N. G. Coldham, M. J. Sauer, G. S. Pope Journal of Applied Toxicology Volume 24,Issue 1, Pages 5-13

There is a very brief summary of Dr Darbre’s research at this link.
http://www.reading.ac.uk/biologicalsciences/about/staff/p-d-darbre.aspx

General information on breast cancer can be found at
http://www.cancerresearchuk.org/breastcancer/breast_cancer/

The full text of a highly cited study of breast cancer incidence in the UK can be read online
http://www.bmj.com/cgi/content/full/311/7017/1391

I have learnt some other things while I have been engrossed in this subject too. Some of the most important information is theoretically freely available on the web, but most scientific journals require you to pay around £20 ($25) to access the full paper.  Because of my job I was able to get hold of nearly everything I wanted without dipping into my own pocket – though even I didn’t read a couple of the papers that might have been interesting because of the expense.  In the internet age, this is a bit of bizarre situation.  For an interested person who doesn’t subscribe to any journals, it would have cost them around £250($325) to have do the research I have done.  This really is unfortunate – especially when you consider that a lot of the work I am talking about has been publicly funded.  I suppose you could have got to the British Library in London and done it there for free, but it would have been hard work.  I made the decision not to reproduce any text or tables from the papers largely on the basis that it would cost money to do so.  This blog doesn’t cost a huge amount to run, but the small revenues from adverts that I run don’t cover the running costs.
The upshot of all this is that anyone who does want to look into the background to a story like the one about parabens in practice can’t easily get hold of the most valuable information.  They are much more likely to end up on those websites and databases that are designed to cause fear that the operators can profit from.  I am not an expert on this kind of thing, but is there any way that papers of particular interest like the ones I have just been reading can be made freely available online to the general public?  I think it would help reassure people a lot and counter to some extent the disinformation spread by scaremongers.

8 thoughts on “Parabens References and links

  1. Pingback: The Truth about Parabens VIII – How can big cosmetic companies regain the trust of the consumer?

  2. subtobv

    Hi Colin, I found your blog recently. A much needed information resource it is, might I add! I found your paraben series extremely useful. I’m a biochemist, although with next to zero knowledge about cosmetic chemistry, so of course I’m a bit more prone to be interested in these kinds of subjects. But still!
    It’s pretty sad that research results are so often “hidden” behind paywalls. In particular, it’s scandalous that the general public doesn’t have access to publications that are financed with tax money. On the other hand, we scientists aren’t too great in communicating our research to the general public, for a multitude of reasons.
    Anyway, just wanted to say hi.

    Patricia

  3. Colin Post author

    Thanks for your kind words Patricia. I try to keep up with biochemistry as much as I can, but it is one difficult subject. You probably spotted that I avoided going into the biochemistry too much. My excuse is that my readers wouldn’t understand it, but I am not sure I do a lot of the time either.

    In particular I haven’t worked out what the esterases in the skin are up to when parabens are applied. I would have thought that they would have dealt with parabens relatively easily. If they were doing what it says on the tin the parabens shouldn’t get into the bloodstream in the first place. But Darbre’s data shows the damn things there, and even in roughly the same proportions you would expect for the different side chains. Any ideas? Is there steric hindrance from the benzyl group? Does the small size of the parabens mean they diffuse through too fast? Any ideas?

    As regards communicating science to non-scientists, I think it is really hard. It took me months to write these particular posts. I don’t know how well I have succeeded but I really wanted anyone to be able to read it and follow my arguments regardless of their background knowledge. You only have a chance of doing it if you really understand the subject yourself, and I often found that in fact I didn’t and had to go back and read stuff again until I did. I wonder if scientists spent more time trying to communicate to non-scientists they might find that it made them better scientists.

  4. subtobv

    I know very little about skin esterases so I did a quick search. The amount of esterases depends on the region of the body, according to the 2007 study by Jewell et al. on minipig (I only read the abstract, don’t have access), so there could be one explanation there, different topical applications may yield different results. From what I quickly read, some of these skin esterases are acting on quite different substrates (they’re non-specific), with varying degrees of polarity and size, so in principle one would have a hard time thinking steric hindrance would be a major factor. However, a particular non-specific enzyme may have kinetics depending on the substrate, that is, it will act more readily on some substrates than others, exactly because they are structurally different. So the diffusion factor may be the most interesting one, because it will determine how quickly parabens get into cells and how quickly they can diffuse to meet esterases and finally how esterases react to them. I read that parabens are absorbed quickly, but I don’t know exactly how “quickly” this is… there sure is a lot of dermis to go through until they reach blood vessels, but on the other hand maybe the amount of absorbed parabens overwhelms the active esterases, and some “escape” their action. Impossible to tell without knowing in vivo concentrations of either. Also, are they diffusing “freely” or in conjunction with other molecules from the cosmetic? Via the lipid bilayers or penetrating the cytosolic environment (that is, how hydrophilic are they?)
    Well, this is all just speculation, largely driven by my lack of knowledge about how these molecules behave 🙂 but it’s easy to see that it is a complex problem. In the end, what we know for sure is that parabens are indeed absorbed, and at least partially metabolized and excreted. It does seem we need more studies about tissue accumulation and its effects.

  5. Sandra L

    Hi Colin!

    I didn’t know your blog before today (I got here from lipglossing) but I have to say you are doing a very interesting work with it. 1st of all, I’m a biochemist, almost finishing my PhD on Biomedicine. I work in reproductive endocrinology so I’ve became interested on the paraben issue a long time ago. Although it has nothing to do with my own research I happen to have psoriasis, so everything I put on my skin reaches my blood stream a lot quicker than it should. Using body lotions with parabens in the past has messed up my endocrine system. So I simply don’t believe when cosmetic companies say they are not dangerous, because I know they are.
    Enough on me, if you want to access some of those papers without paying, e-mail me. I have free access to many journals (not all unfortunatly) so I can try getting them for you.
    Keep up with the good work

  6. Dr Barbara Olioso

    Hi Colin

    thank you for sharing your expertise and knowledge on cosmetics and for for your genuine will to investigate with an open mind on the hot topic of parabens. That is a hot topic for me and I did some posts one my blog about it where I share some images DR Philippa Darbre kindly sent me. I know the test she did is simple (she incubated breast cancer cells with and without isobutylparaben) and does not reproduce in vivo conditions, however my position is we need more tests because present literature is contradictive. For example I wonder why nobody repeated Dr Darbre’s work, ie the one in the controversial 2004 article…
    you can have a look at the images here
    http://organatural.typepad.com/organatural_the_blog/2009/11/parabens-new-evidence-you-can-see.html
    This is just to show you there is some free information out there on parabens…
    Many thanks

  7. Colin Post author

    Thanks for that link Barbara. I think the reason nobody has repeated Dr Darbre’s work is very simple. You need to go through a lot of regulatory hoops to get hold of human tissue to work on.

    Although I personally think that there might be something in the paraben causing cancer story, I would hate to have the job of convincing an ethics committee that there was a serious public health issue at stake. I think that most toxicologists would conclude that the possible link is simply too far fetched to merit investigation.

    The objections raised in the comments by Dene Godfrey are quite strong ones.

    But it is good to see this kind of king being made public outside of the scientific journal system. I think the benefits of being open outweigh the risks of misinterpretation.

  8. Judi

    Hi, Just been diagnosed with rather severe allergies to MANY of the preservatives, (several of the parabens, MCI/MI, as well as many formaldehydes) so your info is QUITE helpful. Not sure if you’re still out there since most of these posts are quite old. Is there an easy way to make my own skin care products??? That carbomer plus something (that I’m not allergic to) would be nice I think…

Leave a Reply