Sciencemadness Discussion Board

Drinking Heavy Water (D2O)

crazyboy - 12-7-2013 at 19:06

I recently tasted about 2ml of heavy water and found that it had a slightly sweet taste, I thought this must have been the placebo effect or contamination because everything I had seen said that it tasted exactly like light water. However, I found a source which claims that it has a sweet taste which seems too unlikely to be coincidence. Has anyone else experienced this? I don't imagine many people have tasted heavy water, I was simply curious and wholeheartedly expected it to taste exactly like normal water.

bfesser - 12-7-2013 at 19:21

Quote: Originally posted by crazyboy  
I found a source which claims that it has a sweet taste which seems too unlikely to be coincidence.
I'm curious. Please, share the source. Also, did you spit or swallow?

crazyboy - 12-7-2013 at 19:39

http://articles.mercola.com/sites/articles/archive/2009/01/10/could-drinking-heavy-atoms-lengthen-your-life.aspx

The source isn't exactly reputable nor is the rest of the content in the article particularly legitimate.

Also this old Pop Sci article

http://books.google.com/books?id=eiYDAAAAMBAJ&pg=PA22#v=onepage&q=sweet&f=false

I found numerous references claiming it tastes identical to water only differing in viscosity, but that does not match my experience.

Swallow, couldn't help it :D

bfesser - 12-7-2013 at 19:51

I'm sure your enzymes are enjoyed the challenge. Was it semi-heavy (HDO), heavy-oxygen (H<sub>2</sub><sup>17</sup>O or H<sub>2</sub><sup>18</sup>O), or vanilla (D<sub>2</sub>O)? Thanks for the links.

This fascinates me. Would you mind if I split this out as a new thread?

[Edited on 7/13/13 by bfesser]

crazyboy - 12-7-2013 at 21:19

Quote: Originally posted by bfesser  
I'm sure your enzymes are enjoyed the challenge. Was it semi-heavy (HDO), heavy-oxygen (H<sub>2</sub><sup>17</sup>O or H<sub>2</sub><sup>18</sup>O), or vanilla (D<sub>2</sub>O)? Thanks for the links.

This fascinates me. Would you mind if I split this out as a new thread?

[Edited on 7/13/13 by bfesser]


99.9% D2O from Cambridge Isotope Laboratories, Inc.

Go ahead.

Also found this: http://www.sciencemag.org/content/81/2098/273.2.citation but I have no access. Anyone?

[Edited on 13-7-2013 by crazyboy]

phlogiston - 13-7-2013 at 13:29

This sparked my curiosity as well, and I just tasted 0.4 ml of D2O too.
It did taste a little bit sweet to me, but I may have been biased by your report. I took a 0.4 ml distilled water sample immediately after and I am not convinced I would be able to distinguish between them in a double blind test.

I think part of the problem is that taste perception is much influenced by what you ate/drank just before, appetite, etc.

I know several people that drank 100 ml recently for an experiment and I will ask them if they noticed anything about its taste.

I have recently done an experiment myself for which I had to feed lab mice various concentrations of heavy water (up to 50%). They did drink a little more than normal, but it is impossibly to say why. Possibly, they like the taste. But they may also feel more thirsty from it or something.

Endimion17 - 13-7-2013 at 15:21

If the mice have been on a prolonged diet consisting of up to 50% heavy water intake, they well might be - thirsty.
Heavy water is not something enzymes can cope with. They've evolved a long, long time ago, in a light water environment.

jock88 - 13-7-2013 at 15:54


Drinking distilled (very pure) water gives a tasted that is different than tap (or more 'ordinary') water.

phlogiston - 13-7-2013 at 16:59

Yes Jock88, I know and that is exactly why I took distilled water, as I am sure the high purity grade D2O more closely resembles distilled water in terms of dissolved salts content, etc. than tap water.

Endimion17, in fact the mice that were on >40% D2O were noticeably affected. 1 died before the end of the experiment, and the others failed to gain weight. The 50% group even lost a little weight, which is usually taken to be a sign of bad health in mice experiments. Some enzymes work normally in D2O, but some are affected. Especially the ones in which hydrogen bridges play an important role in the catalytic mechanism. One of the first things that happens when you give mice even relatively low concentrations of D2O is that they become infertile. Fortunately, I already reproduced :)

[Edited on 14-7-2013 by phlogiston]

subsecret - 13-7-2013 at 18:48

Quote: Originally posted by phlogiston  
. . . ones in which hydrogen bridges play an important role in the catalytic . . .

[Edited on 14-7-2013 by phlogiston]


It is said that heavy water may be quite poisonous, due to the fact that it behaves differently during physiological processes. I wonder what the people who drank 100ml thought about it...

Endimion17 - 13-7-2013 at 21:49

Quote: Originally posted by phlogiston  
Endimion17, in fact the mice that were on >40% D2O were noticeably affected. 1 died before the end of the experiment, and the others failed to gain weight. The 50% group even lost a little weight, which is usually taken to be a sign of bad health in mice experiments. Some enzymes work normally in D2O, but some are affected. Especially the ones in which hydrogen bridges play an important role in the catalytic mechanism. One of the first things that happens when you give mice even relatively low concentrations of D2O is that they become infertile. Fortunately, I already reproduced :)

[Edited on 14-7-2013 by phlogiston]


How low are we talking about, and how long do they have to be on such diet for the first symptoms to occur?
Quote: Originally posted by Awesomeness  
It is said that heavy water may be quite poisonous, due to the fact that it behaves differently during physiological processes. I wonder what the people who drank 100ml thought about it...


No, it it not quite poisonous. It has been checked, it's not a mistery. You can drink a lot of it and nothing will change. Half a glass of heavy water is completely harmless for humans. It's when you continue prolonged diet consisting of high concentrations of heavy water that triggers the start of the symptoms, because the body lacks a suitable reactant for the whole enzyme machinery.
Our metabolism is a huge and complex set of numerous biochemical feedback loops made out of proteins and its basis is catalysis at 37 °C. We're a biochemical machine that is aware of itself.

I'd really like to drink few glasses of heavy water, but I probably never will because that would be a huge waste of money and I doubt I'll ever be rich enough to try that. :)

bfesser - 14-7-2013 at 09:12

I've always wondered if the D<sub>2</sub>O is recovered after such experiments. I've assumed that in the early 1930's this was mandatory, due to the difficulty and expense in isolating even small quantities. Do you recover all water from the mouse bodies, perspiration, and urine? It seems like it would make sense to do so, as the starting concentration of heavy water would be much higher than for a regular water feed stock. If I were to ingest heavy water, I would at least filter and distill the water from my urine afterward.

phlogiston - 14-7-2013 at 11:33

No, it goes to waste, except for the samples of urine, blood and tissues I took for the purpose of the experiment. As chemicals go, D<sub>2</sub>O is not really very expensive, especially if you don't need 99.99%. For the total cost of an experiment like that, the price of the D<sub>2</sub>O is insignificant. The experiment consumed 4 liters of 70% D<sub>2</sub>O for about $375 per liter, whereas we spend a 5 digit figure on the animals and their treatment alone. And then you have to consider the cost of the people doing the experiment, and the cost of publishing the paper eventually, etc. And even if I would recover some D<sub>2</sub>O, I can't easily use it for further experiments because I will have to justify in my papers using a strange preparation I purified myself from waste mouse urine rather than some I bought from a reputed suppplier. It is already difficult enough to do good science, we don't want to make it even harder. Also, we don't have time for that. It'll cost more to recover the D<sub>2</sub>O than to buy it.

When using radioactive isotopes, the story is different ofcourse. Then everything the mice secrete becomes radioactive waste and has to be collected. Very messy.

[Edited on 14-7-2013 by phlogiston]

bfesser - 14-7-2013 at 14:09

I just wondered if perhaps the D<sub>2</sub>O enriched fluids were sent back to the company that isolated it to begin with. Thanks for your response.

Acidum - 20-7-2013 at 13:07

About mice experiment, you said they have been drinking more heavy water than usual, most likely because of organisms inability to use it. Did they pee more because of the same reason?

phlogiston - 21-7-2013 at 14:14

I don't think the reason is that they are unable to use it.
The majority of enzymes/processes work fine in D2O. Some will be just slightly less efficient/fast but that is not usually a big problem to organisms.

I think the most plausible explanations are:

1. It affects the osmoreceptors in the hypothalamus
2. The renal function is affected
3. The mice like the taste of D2O

I don't know if they peed more, but it is likely since mice essentially cannot sweat.

SM2 - 22-7-2013 at 06:49

AFAIK, most D2O is made in slow breeder types. Drinking a cup WILL RUIN YOUR DIET, as it is heavier than simple H2O, but no, it won't make you glow. If you had access to a liter of D20, there are lots of fun physical experiments you could perform. Freezing experiments. Ice Cubes of D2O dropping to the bottom of a glass of water, ect.

seanspotatobusiness - 28-8-2015 at 07:38

Quote: Originally posted by crazyboy  
I recently tasted about 2ml of heavy water and found that it had a slightly sweet taste, I thought this must have been the placebo effect or contamination because everything I had seen said that it tasted exactly like light water. However, I found a source which claims that it has a sweet taste which seems too unlikely to be coincidence. Has anyone else experienced this? I don't imagine many people have tasted heavy water, I was simply curious and wholeheartedly expected it to taste exactly like normal water.


I can confirm that it has a sweet taste. I drank some low percentage of it for a medical study investigating the effect of diet on gluconeogenesis. It had a very unpleasant disorienting effect on me and the other subject I was with although the PhD student had told us that it was indistinguishable from light water.

Thinking about the taste (which was not so unpleasant at the time) makes me feel a little ill but not as ill as I used to feel (this experiment was in 2007/2008).

Rats that are given no choice but to drink heavy water die within 14 days and those that have a choice go for the light water: http://www.ncbi.nlm.nih.gov/pubmed/967900
Quote: Originally posted by phlogiston  
I don't think the reason is that they are unable to use it.
The majority of enzymes/processes work fine in D2O. Some will be just slightly less efficient/fast but that is not usually a big problem to organisms.


I must disagree with the suggestion that altering the kinetics of enzymes is not a problem to organisms. Drinking it affected me (as I describe above) and kills rats if they have no alternative water.

[Edited on 28-8-2015 by seanspotatobusiness]

blogfast25 - 28-8-2015 at 09:01

Heavy water effects on animals:

https://en.wikipedia.org/wiki/Heavy_water#Effect_on_animals

MrHomeScientist - 28-8-2015 at 12:14

Did you know you were drinking heavy water at the time? Somehow I suspect these reports of a difference in taste are all psychological. A blind taste test is needed!

phlogiston - 28-8-2015 at 15:46

Quote: Originally posted by seanspotatobusiness  

I must disagree with the suggestion that altering the kinetics of enzymes is not a problem to organisms. Drinking it affected me (as I describe above) and kills rats if they have no alternative water.


The dizziness you experienced is quite common. The researchers should have warned you about. A colleague says that approximately half of his subjects that drank 150 ml D2O experienced it. I once drank 200 ml but did not, so it is probably variable between people (I never experienced motion sickness either and not for lack of trying).

The vast majority of enzymes works fine in D<sub>2</sub>O, although a few enzymes are sensitive to its effects and they may be critical.

blogfast25 - 28-8-2015 at 15:54

Quote: Originally posted by MrHomeScientist  
A blind taste test is needed!


Fully agree.

I wouldn't rule it out a priori though. For example, recent research found deuterium to suppress the mutation rate of some micro-organisms. Bizarrely, the effect seems to be caused by quantum tunnelling. Ordinary H atoms in the AC and CT bonds in DNA can tunnel, thus favouring one-base mutations. But the twice heavier D doesn't tunnel so well.

QM has recently also been found involved in the sense of smell of some animals and the 'compass' of Robins.

So stranger things may yet lie ahead!

[Edited on 28-8-2015 by blogfast25]

aga - 28-8-2015 at 16:12

Strangeness is a given.

Much more to come for sure.

Edit :
Quote: Originally posted by blogfast25  
QM has recently also been found involved in the sense of smell of some animals and the 'compass' of Robins.

Not so.

Robins are unlikley to have much knowledge of QM, so more likely that their behaviour is influenced by Real World phenomena that QM is able to Model to some measurable degree.

[Edited on 29-8-2015 by aga]

crazyboy - 28-8-2015 at 18:31

Quote: Originally posted by seanspotatobusiness  


I can confirm that it has a sweet taste. I drank some low percentage of it for a medical study investigating the effect of diet on gluconeogenesis. It had a very unpleasant disorienting effect on me and the other subject I was with although the PhD student had told us that it was indistinguishable from light water.

Thinking about the taste (which was not so unpleasant at the time) makes me feel a little ill but not as ill as I used to feel (this experiment was in 2007/2008).


Interesting, I'm glad someone has confirmed the sweet taste. The dizziness is interesting, how fast was the onset and how intense was it?

I attached an interesting review of deuterium which notes among other things that high levels of deuterium may reduce damage from gamma radiation and that deuteratred drugs may resist cytochrome P450 degradation (the authors suggest deuterated insecticides as a possible application).

Attachment: Pharmacological uses and perspectives of heavy water and deuterated compounds.pdf (131kB)
This file has been downloaded 693 times

careysub - 28-8-2015 at 22:53

Quote: Originally posted by phlogiston  

The dizziness you experienced is quite common. The researchers should have warned you about. A colleague says that approximately half of his subjects that drank 150 ml D2O experienced it. I once drank 200 ml but did not, so it is probably variable between people (I never experienced motion sickness either and not for lack of trying).


Intriguing, too bad heavy water is $90 per 100 mL at United Nuclear (the only source I know of), it would cost $135-180 to duplicate. Not prohibitive I suppose, but a pricey beverage for sure.

Nicodem - 29-8-2015 at 01:52

Recently, the phase III clinical trials of SD-809, a d6 version of the drug tetrabenazine, were completed and the drug will be applied for approval. This is an interesting example of how deuteration can dramatically reduce the metabolism of a drug, while all the other activities remain the same.

SD_809.jpg - 37kB
Quote: Originally posted by blogfast25  
QM has recently also been found involved in the sense of smell of some animals and the 'compass' of Robins.

Indeed, the smell is currently believed to be connected with the vibrational modes of a molecule. The D-O bond does not have the same vibrational frequency as the H-O bond. It is therefore not unusual that people can distinguish the taste and that rats recognize D2O by smell and taste (as described in the Proc. Soc. Exp. Biol. Med. article linked above.

phlogiston - 29-8-2015 at 02:01

The dizziness is usually attributed to a small difference in density in the fluid in two separate compartments in the vestibular organ, which is important for the sense of balance. The difference arises because the rate of diffusion of D<sub>2</sub>O and H<sub>2</sub>O into these two compartments is different. The effect is also observed upon ingesting glycerol or ethanol.

So, D<sub>2</sub>O seems like a very expensive means to become drunk really briefly.

[Edited on 29-8-2015 by phlogiston]