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Some relatives of mine think that drinking sea water is good for health, but I highly doubt it. They claim that drinking small amounts of sea water daily helps people to be healthier (reference provided by Oddthinking).

Is this regular sea water consumption good for your health? If so, is there any scientific research about sea water and health benefits?

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amb
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  • What benefits do they claim? – Oddthinking Dec 25 '12 at 13:47
  • Well, they say that it has healing properties... – amb Dec 25 '12 at 13:50
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    [Welcome to Skeptics](http://meta.skeptics.stackexchange.com/questions/1505/welcome-to-new-users)! We want to focus our attention on doubtful claims that are widely held or are made by notable people. I'm trying to help you [provide some references](http://meta.skeptics.stackexchange.com/questions/882/what-are-the-attributes-of-a-good-question/883#883) to places where this claim is being made. Is this similar? http://www.harmonikireland.com/sea-water/ – Oddthinking Dec 25 '12 at 14:25
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    What quantities of water are we talking about? – Christian Dec 25 '12 at 17:05
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    Sea water is too salty for consumption as a sole supply of water. Is the claim about mixing it with fresh-water and consuming an isotonic mixture, or simply having a mouthful of seawater as a medicine occasionally? – Nick Dec 26 '12 at 16:48
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    I've heard the claim that people who are stranded at sea are most at risk of dying of thirst. – Sam I Am Dec 26 '12 at 21:37
  • The human body needs water to digest salt and the salt/water ratio of sea water is too high, i.e. more fresh water is required in addition. In other words: you will dehydrate (to the point of death by dehydration) if you only drink sea water. On the other hand, drinking a little bit of sea water now and than might be good for your salt intace. So please edit your question to clarify about how much sea water consumption we talk about. – Martin Scharrer Dec 26 '12 at 22:45

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No, it is toxic, causing convulsions, dehydration and death in mammals.

The toxicities of Na+, Cl- and Mg++ ions in sea water and in artificial solutions were investigated. Convulsions commonly followed intraperitoneal injection of hypertonic salt or sucrose solutions in rats, but the convulsions due to sea water and NaCl solutions differed from sucrose or urea convulsions. Respiratory distress preceded death. Even in thirst, little sea water was taken voluntarily. Salt solutions or sea water given by stomach tube caused dehydration. Plasma Cl- concentrations reached the same low level after lethal doses by either route. Dogs and seals vomited sea water from the stomach. Seals were not more resistant than the other mammals. The lethal dose of sea water for rats was decreased by previous dehydration. Some adaptation appeared after repeated sublethal doses.

—Toxicity of sea water in mammals by ALBRECHT, C. B., Journal American Journal of Physiology 1950 Vol. 163 pp. 370-385

It's a well cited 1950's article so I assume it's fairly authoritative.

Sklivvz
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  • The quote you gave only concerns animals. That is a good way to make hypothesis about how humans will react, but we cannot assume that humans will respond in the same way as animals. Is there any evidence that sea water is toxic to humans? – Kenshin Dec 27 '12 at 02:16
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    Why wouldn't it be as humans *are* mammals? There's probably some other lesser research, however normally poisons cannot be researched on humans for ethical reasons. – Sklivvz Dec 27 '12 at 03:04
  • Well fluoride has been shown to have neurotoxic effects in rats. Does this mean it will have the same effects in humans? – Kenshin Dec 27 '12 at 03:07
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    The article is about *mammals* in general. The only exceptions are marine mammals who have specific resistances which are also studied. – Sklivvz Dec 27 '12 at 03:09
  • @Chris fluoride is a neurotoxin in humans as well, all depends on the dose. And those rats like in all such tests were no doubt given doses that are thousands or millions of times higher than they'd ever ingest during a normal life. Think the "study" that showed shampoo causes cancer, IF you wash your hair a thousand times a day with 10 bottles of shampoo per washing and let it soak for 10 minutes each time. – jwenting Oct 06 '13 at 15:25
  • @jwenting whew! there are only 1440 minutes in a day, so I guess washing 1000 times/day at 10 minutes each isn't a risk I have to face... :-) – Michael Jun 03 '14 at 15:46
  • -1 The question says small amounts which, though not specific, would mean consuming a quantity that's not toxic. I don't think this answers the question at all! – Highly Irregular Sep 11 '15 at 02:50
  • @HighlyIrregular There is no "safe" quantity, but of course the effects are related to quantity. As far as I can tell from the sources, even a small amount causes dehydration, in proportion. – Sklivvz Sep 11 '15 at 11:08
  • @Sklivvz that's like saying there's no safe quantity of table salt isn't it? When consumed with enough water, there's no problem. I'd expect the same to occur with sea salt, or sea water, but there may be something in sea water other than sodium chloride that is actually healthy. I wouldn't assume there is, but I'm open to the concept! – Highly Irregular Sep 12 '15 at 10:53