Water can’t prevent dehydration (according to the European Union)

I came across this story this morning. In short, it tells us that EU bureaucrats have forbidden companies that sell bottled water from claiming that water can prevent dehydration. I’ve not read the ruling, just the report I link to. But it seems, on the surface, to be a decision which has taken considerable time and resources which was, in the end, motivated more by politics than anything else.

I honestly believe that maintaining hydration is one of the simplest, easiest and cheapest things individuals can do to maintain their energy and vitality. I have seen countless individuals with low fluid intakes experience considerable uplift in their general wellbeing just by upping their consumption of water and other beverages. The effect appears, to me, to be incredibly consistent. It might be a giant placebo response, of course, though trust me when I tell you that if that’s the case, few people will mind: it’s feeling better that they principally care about, not the precise mechanism(s) that brought that about.

The EU ruling took my mind to a practice known as ‘evidence-based medicine’ or ‘EBM’ for short). This is a term that is generally taken to mean medicine which has a solid research base to support it. However, should we dispense with things that have no evidence to support them even though they seem like the right thing to do and experience shows to be broadly beneficial?

If we do dispense with such things than we doctors better shut up shop – that’s because the great majority of medical practice is not supported by rigorous scientific evidence. Surgery is a prime example. When someone comes in with the signs and symptoms of an infected appendix, surgeons do not wait for ‘randomised controlled trials’ before they operate. Neither do they wait for sufficient supportive evidence before they take steps to stem significant bleeding sustained during injury (they just get on with with saving people’s lives, even in the absence of evidence).

Some years ago I read a letter in the British Medical Journal from James Michelson – Professor of orthopaedic surgery based at George Washington University in Washington in the US which should remind us all of why evidence-based medicine should not be the only evidence in town. It highlights why common sense has a role in medicine too. Here is an extract from that letter.

In the course of practice in orthopaedic surgery (although not documented in the literature), it has been my experience (those of you who adhere to the EBM doctines [sic] hopefully will excuse this phraseology) that when I hit my finger with a hammer (or mallet, for that matter), my finger hurts. It is even worse if I use a power tool (like drilling through the finger). My question: how many times do I have to do this before I can say that I have sufficient evidence to potentially causally link the hammer blow to my finger hurting? And what do I use as the control?

One of my teachers in medical school once noted that fields such as Orthopaedic Surgery were very difficult for some physicians to master because they required the exercise of “common sense”.

Professor Michelson’s got a point, I think. Those who believe the EU’s banning of the claim that water can combat dehydration is nonsense have a point too.

34 Responses to Water can’t prevent dehydration (according to the European Union)

  1. Angela 18 November 2011 at 5:19 pm #

    Is the very word ‘dehydration’ rooted in the word for water? This seems bonkers…

  2. Valey 18 November 2011 at 5:35 pm #

    Dear Dr Briffa,
    Thank you very much Doc for this article.

    This indeed is quite intriguing piece of article and leaves a lot to be desired as to what do they opine combat dehydration if not water. Maybe we need their definition of dehydration it could well be that we differ in perception or definition.

  3. John Walker 18 November 2011 at 6:13 pm #

    It doesn’t seem bonkers to me. It IS bonkers. I would tell the idiots who appear to know nothing, where to go.

  4. Jo Jacobius 18 November 2011 at 6:18 pm #

    John, your point about EBM is spot-on. Of course water isn’t the only means to hydrate the body. Much of our fluid intake comes from the foods we eat but it is surely common sense that when choosing liquids to drink, if you want a fluid that tastes good, is as natural as can be, is tooth-kind and calorie free, bottled water (much of which comes in its natural state) is a good place to start. This latest guidance from the EU is bonkers – up there with the ‘British Sausage’ episode of Yes Minister all those years ago – except that worryingly this is real and not a figment from Sir Humphrey’s desk. That water is fundamental to life is,as you indicate, an example of plain common sense.

  5. Karen 18 November 2011 at 6:57 pm #

    Have people nothing better to do than ban wording. Think of all the money & time wasted on this. Who is pushing such a trivial matter? One of the sugar packed soda groups I suspect.

  6. jayney goddard 18 November 2011 at 7:08 pm #

    Scary stuff John – can they really be this dim?
    Jo – your reference to “Yes Minister” is spot on and really made me laugh – thanks – it was a bit of a dreary day otherwise:-)

  7. Feona 18 November 2011 at 7:15 pm #

    Bonkers is right, but then Eurocrats are on the biggest gravy train there’s ever been. They probably feel they have to at least look as if they’re working so as to hang on to their comfy lives and enormous salaries.

  8. Paul Rowlandson 18 November 2011 at 7:28 pm #

    The comments by Prof Ratcliffe of the Nutrition Society (quoted at the far end of the Telegraph report) make sense. He said

    “Dehydration was usually caused by a clinical condition and that one could remain adequately hydrated without drinking water.

    and: “The EU is saying that this does not reduce the risk of dehydration and that is correct.

    “This claim is trying to imply that there is something special about bottled water which is not a reasonable claim.”

    Ratcliffe’s comments seem reasonable to me. The Telegraph misses no opportunity to criticise the EU for the most spurious reasons. Sorry to see you getting on the bandwagon.

  9. John Briffa 18 November 2011 at 7:47 pm #


    Prof Ratcliffe states that:

    “Dehydration was usually caused by a clinical condition and that one could remain adequately hydrated without drinking water.”

    Let me ask you a question: Do you believe that drinking little or no water could lead to dehydration?

    And, yes, I’m sure it’s quite possible for people to maintain good hydration without drinking water. But here’s the real issue: could drinking water help maintain hydration and prevent dehydration? (that’s a rhetorical question, of course).

  10. Marci 18 November 2011 at 8:37 pm #

    In short, it tells us that EU bureaucrats have forbidden companies that sell bottled water from claiming that water CAN prevent dehydration.

    You meant to say CAN’T here not CAN, right?

  11. John Briffa 18 November 2011 at 9:02 pm #


    The sentence is correct as it stands.

  12. Liz 18 November 2011 at 9:09 pm #

    So we aren’t allowed to say that water “can” prevent dehydration?!

    Here’s a definition of dehydration:-
    1. The process of removing water from a substance or compound.
    2. Excessive loss of water from the body or from an organ or body part, as from illness or fluid deprivation.

    It is a fallacy to say that because other substances might also prevent dehydration that therefore water doesn’t prevent it.

    Perhaps companies should only be able to say that bottled water is just one part of the ways of preventing dehydration, for those people that can’t work it out for themselves!
    However, if people are also getting hydration from other drinks/foods, it will be the water content of those other drinks and foods that rehydate.

    NHS health guidelines state clearly that drinking water helps avoid dehydration, and that Britons should drink at least 1.2 litres per day.
    Is the NHS to banned from saying this too!

  13. Diana1 18 November 2011 at 9:20 pm #

    We are continually being told that evidence-based medicine is the gold standard to which medicine aspires. There is still a long way to go. I think I saw a reference to the effectiveness of treatments in comments on your blog about 3 years ago. I have just revisited the site http://clinicalevidence.bmj.com/ceweb/about/knowledge.jsp Based on randomised controlled trial evidence currently 51% of 3000 treatments are rated of unknown effectiveness and only 34% are considered beneficial or likely to be beneficial. A lot still depends on the clinician’s judgement!

  14. NickB 18 November 2011 at 10:04 pm #

    I think there is a big focus on the word “dehydration” here, whereas I suspect the EC is focused more on the word “prevent”.

    For example, if food companies were claiming that a Product A *prevented* Condition B, particularly without making any statement about *how much* of Product A was required to “prevent” Condition B, then I imagine everyone here would be up in arms.

    I don’t really see this as different. A bottled water company selling me a 250ml bottle of water saying it “prevents” dehydration would be misleading in the extreme. Even selling me a 1 litre bottle of water and not saying that I have to drink it all within a certain period of time in order to “prevent” dehydration is still misleading.

  15. Rachel 18 November 2011 at 10:36 pm #

    If your electrolytes are all out of whack no amount of water’s doing to quench your thirst.

    Also, this is an opinion given regarding interpretation of an EU regulation, not a ban.

    Bottled water companies were trying to misuse an EC regulation in order to get “official” backing for marketing water as a medicinal cure for a disease. They would then be able to tell us we all have to drink “a significant amount” of their product specifically in order to prevent “disease” (dehydration).

    As always the truth takes a back seat to a catchy headline in the British press.

  16. Everett 18 November 2011 at 10:50 pm #

    Does eating prevent starvation?

    If a company states their product is a “satisfying” snack, implying “satiety,” are they going too far?

  17. Esther 18 November 2011 at 10:53 pm #

    I’m with Paul Rowlandson. Maybe it’s an admittedly feeble attempt to say that bottled water is no better than any other water at dealing with the problem of not enough water. I hesitate to use the term dehydration which is a rather extreme variety of thirst and I would agree is a clinical condition. I think it is worth remembering that bottled water is an environmentally TERRIBLE and very largely unneccessary “product”!

  18. Michael 18 November 2011 at 11:08 pm #

    Straight bananas and cucumbers. Need I say more?

  19. Jill H 19 November 2011 at 4:45 am #

    I am an absolute believer that drinking water keeps me feeling healthier with a clear skin (or that was what all the beautiful models told me in the 60’s) and clear head but I read this differently. I agree with Paul and Esther. As I read this article in the Telegraph what for me it is saying is that this is wording that two german professors who advise food manufacturers (and water produced in ‘single use’ plastic bottles is a gold mine for the food manufacturing industry creating revenues of, I have read, billions of dollars) how best to market SINGLE USE PLASTIC BOTTLED WATER to us – not the health benefits of water. I think what Prof Brian Ratcliffe said is reasonable ‘This claim is trying to imply that there is something special about bottled water which is not a reasonable claim’. Single use plastic – a plastic bottle we drink from which may get recycled but in many cases not is a major problem to our world. Apparently the US alone consumes 50 billion disposable bottles of water every year. http://www.telegraph.co.uk/earth/environment/5208645/Drowning-in-plastic-The-Great-Pacific-Garbage-Patch-is-twice-the-size-of-France.html This also appeared in the Telegraph and suggests that we rethink our use of ‘single use’ plastic. I always think it is interesting how green my grandmother was – she knew nothing of ‘green issues’ but using plastic bags once and plastic water bottles once and then throwing them away would have seemed madness and unacceptably wasteful to her.

  20. Chris 19 November 2011 at 4:57 am #

    (Eau my god!)

    I think the electrolytes issue is a bit of a distraction. Solid foods and metabolism would maintain electrolytes in a normal setting. Apart from water content of food itself water is the best way sustain hydration.

    This is a bonkers ruling by the EFSA but I have some sympathy for EFSA as making or permitting functional claims for foods becomes a murky territory in which common sense loses its’ way against the ‘spin’ of marketing.

    What is as bonkers as ruling out certain functional claims for some foods is EFSAs history upon debate and ruling(s) concerning other permitted claims, ie ones that have bee ‘ruled in’, for other foods, or for other far from natural concoctions that masquerade as food.

    It reminds me of an American ruling that the tomato, botanically very definitely a fruit, had to be re-branded a vegetable in the name of (market) protectionism.

    What we think of as a free market, very often is far from it, and what we think of as a democratic society sometimes exhibits less in the way of liberty and less in the way of economic democracy
    (a wide and general use of the term) that we may carry within our perception. The ‘effect’ is traceable to a ’cause’, but is rarely if ever linked with it in practice.

  21. audrey wickham 19 November 2011 at 10:54 am #

    Is it possible that the recent scare about water in plastic containers being dangerous has been translated into water is not good for us?

  22. Esther 19 November 2011 at 2:55 pm #

    Thank you Jill H. Much more clearly put than I did it and with the evidence. Audrey, can you give a reference for the plastic container scare? thanks.

  23. helen 19 November 2011 at 11:25 pm #

    The whole concept of the EU concerns me. Who are these people and how did they get such a say in the lives of millions of people??? Did the whole of Europe hold elections to vote these people in? Do they take precidence over the elected governments in Europe? To an outsider it seems that indeed they do. Now they are banning the sellers of water from claiming that water is good for rehydration. All I can say to the people of Europe is get rid of these dangerous bozzo’s before you all go down the drain having a common currency is one thing but telling people how to live, eat, drink and breathe is beyond a joke. Just let people decide for themselves if the bottlw of water they buy is because they are thirsty especially when some tap water isn’t really fit to drink.

  24. deirdra 20 November 2011 at 12:44 am #

    I suspect they think the average person is too dumb to realize that water from the faucet can also prevent dehydration; faucets don’t come with such labels (yet). Or they may go for a 2-week hike in the desert with only one bottle of the miracle liquid they bought because of its label which promised it would prevent dehydration. Or you get the people who drink several gallons of water and get sick or die.

    So maybe they are just trying to prevent the inevitable. If water is allowed to be labelled as preventing dehydration, then practically every other liquid can be too, and all foods labelled as preventing starvation. Both are considered medical conditions and require a dose of water/food (and medical intervention in severe cases), so it is best to stay completely out of the medical labelling business.

  25. EtuGM 22 November 2011 at 2:24 am #


    Conclusion : this information is a fake.
    Eu don’t say that. Please, if you make an article, check the information before.

  26. John Briffa 22 November 2011 at 5:29 pm #


    The article you link to claims this is the critical phrase:

    The regular consumption of significant amounts of water can reduce the risk of development of dehydration and of concomitant decrease of performance.

    I don’t want to get a bit too rational and exercise common sense or anything, but I actually believe that drinking significant quantities of water can indeed reduce the risk of dehydration. The story is not fake, and neither is the notion that drinking water offers potential benefits for health and wellbeing.

  27. EtuGM 22 November 2011 at 8:37 pm #

    “The regular consumption of significant amounts of water can reduce the risk of development of dehydration and of concomitant decrease of performance.”
    By the way it is true. You nod only nead water for being hydrated, you nead salt too.
    If you drink only distilled water you will die from… Deshydratation ^^.
    But that’s not the question.

    I wanted to speak about the original article (not the one in the tabloïd =)). I was not clear, i apologize.

    I thinked people would read the article and click to the link for the source (to have a comparaison)… My bad, nobody do it ^^. People always surprise me…

    So :
    And, luck, it is in english =)

  28. Dr Andrew Longstaff 22 November 2011 at 9:00 pm #

    On the subject of scientific proof and common sense, it’s worth remembering the reason why there has never been a successfully completed randomised controlled trial of whether parachutes save lives or not. It rurns out that all of those randomised to the non-intervention arm (ie no parachute)suddenly subscribe to the idea of “Theories of the Bleeding Obvious That Don’t Need Testing”,and decline to sign the consent form.

  29. Pete Grist 27 November 2011 at 2:45 am #

    Your hammer example is shameful, as obviously we only need to do it once to have the evidence that it hurts i.e. the evidence base needed.

    Drinking water is different, and you have often said that the colour of your pee is the only required evidence needed. To fix this any water based liquid will do and there is no need to drink great quantities of bottled water (which was the point of the EU report, addressing a general scam).

  30. John Briffa 30 November 2011 at 11:22 am #


    Your hammer example is shameful, as obviously we only need to do it once to have the evidence that it hurts i.e. the evidence base needed.

    You could make the same argument about dehydration Peter. And if you don’t or can’t, the point the author of the letter was making is that we should not be slaves to scientific evidence and embrace common sense and experience. I like to credit my readers with some intelligence by not spelling out some things, but I appreciate sometimes this is not appropriate.

    Even if you didn’t understand the point, Peter, can it really be described as shameful?


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