I am maximally-skeptical that there currently exists any evidence that drinking deuterium-depleted water has health benefits or will cure disease.

Because of our lab's interest in the biophysical effects of heavy water--both heavy-hydrogen water, D₂O, and heavy-oxygen water, H₂O¹⁸--I received a very friendly email inquiry today.  The person suffers from a health problem and currently hopes that drinking deuterium-depleted water will help with that condition.

As a scientist and a health consumer, I am maximally-skeptical of any medical claims related to drinking deuterium-depleted water.  This is despite that fact that I think there's a good chance that cells may behave differently if deprived of deuterium, which exists in all natural water sources.  The reasoning for my skepticism is very straightforward.  There is a dearth of any published scientific or medical research utilizing deuterium-depleted water.  As I will note below, there are less than a dozen research papers on the topic.  So we really don't know.  There is almost no evidence.  We don't know whether drinking large quantities of deuterium-depleted water will be helpful or harmful or negligible.

There is much more evidence, though, that the quantity of water that would need to be consumed is quite large.  Because deuterium is natually-occurring, there's a lot of it in your body!  It would take a long time of drinking lots of D-depleted water to have a systemic effect.  My interpretation of the existing evidence is that by far the most likely outcome of this therapy is that it will generate profit for whomever is selling the D-depleted therapeutic water.

Because I think it's a shame that a Google search for "deuterium-depleted water" is overrun by claims of cures for horrible diseases, I asked the person who wrote me if I could send my response on my blog instead of privately.  So that perhaps our discussion could benefit more people.  The person kindly agreed and so I will post his email:

Dear Steve,
I enjoyed reading your blogs and noted that you work with D2O.
I have a medical condition that I want to treat with alternative methods - one of them is drinking "light" water.
Do you know, or can you suggest any resources for the following:
1. how to make "light' water, with D2O concentration of below 50ppm 2. who does D2O concentration testing in the us for water samples 3. who makes light water (for sale) 4. any scholarly literature on this topic...
Any info will be much appreciated and shared with fellow friends who are in need.
Thank you very very much!!

Here is the reply I would have sent, but instead post publicly:

Dear ___, 

Thank you for your kind message.  I am sorry to hear of your medical condition.  I am not an expert on the medical effects of deuterium-depleted water.  In fact, I am not aware of any medical experts on this topic.  As a scientist, I am maximally-skeptical of any claims of currently-known medical benefits of drinking deuterium-depleted water.  I'm not saying it will help or hurt you, I'm saying that I don't think anyone is close to knowing whether it will be helpful, harmful, or negligible.  There is almost no published, rigorous research on the subject (your question #4), and thus any claims are probably speculation.  I would suggest talking to a medical doctor, which I'd guess you've done plenty of, since they know almost infinitely more about the human body than I do.  However, I would think that any medical doctor, or indeed any living person, would merely have to guess, because I do not see any experimental evidence beyond just less than a dozen published reports which have yet to be challenged or supported. 

Below I will put responses to your specific questions, and I wish you the best, 

Sincerely,

Steve 

1. I don't know of an efficient method for producing mildly-deuterium-depleted water.  The deuterium-depleted water we use in our research is much more depleted.  We obtain it from Sigma, a chemical supply company, and it is roughly $100 per 100 milliliters (a few ounces).  As you may know, you would probably need to drink a lot of water over many days to appreciably deplete deuterium from your body.  This would surely be expensive.  And like I said above, as far as I can ascertain, it's unknown whether it would be helpful, harmful, or negligible.

2. I don't know who does D2O testing.  I'd be skeptical of anyone offering these services related to this medical purpose.  Incidentally, deuterium-rich water is inexpensive.  You could easily mix D-rich water with regular water and see if the purported D2O-testing company is able to correctly discern the difference. 

3. We so far have only purchased from Sigma.  See for example product #195294.

4. I have read two scholarly papers on the subject, both from a research group out of Hungary.  I found both papers very interesting, but I also am highly skeptical of the interpretation of their results.  A good place to find scholarly papers related to biology or medicine is on Pub Med.  This link will hopefully take you to a search for articles related to deuterium-depleted water.  I can only see one that is freely available.  Google Scholar is another place to search, but it will not be limited to biological articles. 

I actually find this topic fascinating, as far as whether life has evolved a beneficial use for naturally-occurring deuterium.  We have a side project in our lab to see whether we can notice any effects on tobacco seed growth.  We're using tobacco seeds because they are tiny, so we don't need much water to see an effect.  We got this idea from Gilbert N. Lewis, who did the initial studies in the 1930's that showed that too much deuterium affects life. One of the reasons I find this side project on deuterium-depletion so fascinating is that I see it as an open mystery.  That correlates well with my skepticism of claims related to therapeutic effects of drinking light water.

Below, I will embed a comment thread from FriendFeed, and also there are potential comments on the blog itself.  I expect them to be a mix of helpful and derisive...hopefully more of the helpful type!