Will drinking blood actually dehydrate you?

[tutorp]

In a survival situation, you'll obviously want to use all resources available to you. If you've managed to catch an animal, its blood is definitely one such resource. However, in survival manuals I've come across, if they mention blood, they say not to drink it, as it will dehydrate you. Other sources, found through Google, on the other hand, say other things.

Now, I do think that the survival manuals have some sort of point. Blood is probably not good for rehydration. There's quite a lot of salt, and quite a lot of protein, and all that will require water for the body to process it. However, my question isn't whether blood will hydrate you; it's whether it will actually dehydrate you. There's a big difference.

Drinking a liter of sea water, your body will supposedly need about 1,3 liters of water to process the salts. That will leave you with a net loss of 0,3 liters. Blood is approximately 3/4's water; will processing the remaining fourth of salt and cells require significantly more water than what's already in the blood, dehydrating you, or merely leave you with a negligible amount of excess water (or a negligible amount of lost water, considering the nourishment from the blood)?

 

[Janne]

Interesting question.
When your body metabolizes fat, it is actually creating water, so calked metabolic water.
I would think that this water plus the "free" water of the blood will be enough to help with the salt

Blood contains Proteins, fat, water and salt.
Plus minerals.
You can survive for a long time eating blood and drinking water.
The Masai in East Africa used to survive on raw cow blood and milk.


Now, during my military survival training, we had to learn how to kill and eat reindeer. The preferred method was to first tap all the blood we could from it before it died.
We all had to drink a kåsa ( kind of cup) of the raw reindeer blood.
All of us, excluding the Same guys, puked it up. It congealed in our stomachs and our bodies could not take that.
Cook it first.

 

[Nice65]

Highly likely it will dehydrate, it needs digesting and that involves more water than it contains. Even the Maasai only use it ritualistically.

 

[Janne]

Not true. Metabolism of fat creates water. Of course you still need to drink your daily dose of water ( which depends on how much you sweat) but you do not need additional water unless you drink liters and liters of blood.

Blood and the lymphatic liquid is where the Sodium (Na) is in the body, but the levels are pretty low. Just over 3 grams per liter Sodium. Approx 7 grams of table salt.
So approx 7 grams of Table salt per approx 1000 grams of blood.
Hence the need to add salt to blood based foods like Blut wurst and Black pudding, so they taste salty/ savoury.

If you get too much salt into you you will just wee it out. Dehydration due to ingesting to much salt (NaCl) is extremely rare, unless you drink pure sea water for longer periods of time, several days minimum.

But if you do that, before you get dehydrated your kidneys will get seriously damaged as they try to get rid of the excess salt, the nefrons get damaged.

Sea water is very salty, about 35 grams per liter. Lots of people think that sea water is of the same salinity as blood, but that myth stems from the fact that the Primordial Sea is thought to have been of the same salinity as the blood of most living organisms today.

 

[forrestdweller]

sorry that I go somewhat : how big would be the risk of catching a parasite or disease this way?! (which is why I'd prefer to cook it rather than consuming raw)

 

[mrcharly]

sorry that I go somewhat : how big would be the risk of catching a parasite or disease this way?! (which is why I'd prefer to cook it rather than consuming raw)

Not off topic at all and depending on the animal I think quite high. I would not drink raw blood from a pig, for example.

 

[Janne]

Not big. Pigs rxcluded!
Most parasites are species specific. Blood is usually sterile, most parasites prefer the intestines.
The more common human blood bourne parasites are Plasmodium ( malaria), Trypanosoma ( Chagas) and HIV ( AIDS) in humans.
Plus some Viruses, like the various Hepatitis. That is if you choose to be a Vampire and drink your friends blood!

Pigs can have Bruccellosis, Trichinosis smongst other.

The chance is tiny as many " primitive" cultures eat undercooked meats, from wild animals that are in comparably high risk of being carriers. Most animals are healthy.
Our own "semi primitive" culture also eat undercooked food, like rare steaks and burgers, beef Tartare, but our live stock is tested so less chance of infections. Meat contains blood, so technically we are ingesting raw blood!

If I had to eat blood, I would cook it if I could.
To sterilize it and also to make it more easy to digest and more palatable.

It is no fun puking up slimy lumps of blood.

 

[santaman2000]

Not true. Metabolism of fat creates water. Of course you still need to drink your daily dose of water ( which depends on how much you sweat).....

.........If you get too much salt into you you will just wee it out........

Ummm, "wee it out" is one of the reasons for dehydration in and of itself. Lost body fluid, is lost body fluid, is lost body fluid. How you lose it is irrelevant (Sweat, urination, mucous, tearing, etc)

 

[Janne]

Ummm, "wee it out" is one of the reasons for dehydration in and of itself. Lost body fluid, is lost body fluid, is lost body fluid. How you lose it is irrelevant (Sweat, urination, mucous, tearing, etc)

Yes, but you wee anyway. With excessive salt intake your wee becomes saltier. You do not sweat or wee mote because you eat more salt.
If you do not drink any water, you become dehydrated no matter how much salt you ingest.

Not enough salt in blood to make much difference....

In addition to the diseases in blood I should add the Zika virus.
There is a case in France now when a woman is thought to have gotten it by oral sex. ( British Daily Mail today)
Zika is in all bodily fluids.

 

[Philster]

On one episode of "Dude Youre Screwed" they dropped Matt Graham off in Africa somewhere and they gave him a pack of cows blood to use as he saw fit - he drank it, but the consensus was that having to digest it would use up more water than it supplied.

 

[Janne]

Maybe TV should have asked somebody that understands digestion? Somebody that went through Med school and passed?

Digesting fat creates water. Digesting protein is done by acids and so on, to break it up into amino acids that are absorbed.

You need to drink extra water if you are on a ultra high protein/ fat diet type Atkins, to lessen the damage done by the ketones.


Media is spreading a huge number of lies and misconceptions about physiology, nutrition, "super foods" and such, without any scientific checks or proof.
Most of us, including guys like me, fall for one or the other.

 

[santaman2000]

Yes, but you wee anyway. With excessive salt intake your wee becomes saltier. You do not sweat or wee mote because you eat more salt......

That's somewhat true; as long as you avoid diuretics. The $64 question is: Is blood a diuretic?

 

[Janne]

The dime answer is: No.

The doctor that pioneered sea survival and inflatable sea worthy boats, Dr Bombard, survived ( just) by drinking fish juice from the meat and blood and eyes, sea water and rain water. He calculated that you could drink a "survival" amount of sea water each day, I do not remember how much. Maybe 1/2 liter?
When he arrived outside the Caribbean, he had leg ulcers, swollen extremities and damaged kidneys. But he survived.

Beer, tea and coffee are diuretics according to science, but loads of people in Europe ( specially Central) never drink anything else.
Still they live well.
I have never seen my dad drink water.

 

[tutorp]

Thank you all for your replies.

Janne: Your thoughts on the matter are similar to my own suspicions. I.e., blood won't really hydrate you, but it won't dehydrate you, either. At least not in relatively small quantities.

As for beer, tea and coffee, depending on the amount you drink in one sitting, they're only mildly diuretic. A cup of tea won't rehydrate you as much as a cup of water, but it will still rehydrate you. If you drink a large enough amount, the diuretic effect will start to set in.

 

[Janne]

I am going a bit off topic now:
The Sami ( lapp jävlar) people in Scandinavia are big coffee drinkers.
Wintertime they use snow to make coffee with.
The way I was tought was this:
For one kåsa ( Sami cup, approc 0.25 l) coffee you melt snow, take about 3 soup spoons of "boiling coffee" grounds. ( a specific course grind, light to medium roast, quite acidic) and a pinch of salt. Heat to a rolling boil, remove from fire. Rest 5 seconds. Repeat three times. Then rest until grounds settle to bottom.
Pour in a kåsa, add a bit reindeer cheese.
NO sugar!

They add salt because the snow water is salt and mineral free. Coffee does not taste good without the salt.



There is a lot of misconception about healthy foods and drink out there. Superfoods? No such thing!

 

[Nice65]

Deleted for my own reasons.

 

[Janne]

Deleted as added nothing to the topic

 

[santaman2000]

Blood drinking aside, you're getting all pompous with your med qualification.

I reckon there are foods that are better than others. "Superfoods? No such thing!" That's a crock of rubbish, there are certainly superfoods. How about fresh sprung Mung beans, cress, alfalfa, beetroot, tomato, spinach, watercress?....

I gotta partially agree with Janne (likewise with my doctor and my dietitian); those are good, healthy foods. Nothing "super" about them though. If they were super, we'd be the healthiest people on Earth.

.....

What you call super foods is what most people with a sober, functioning brain call healthy foods. Super what? Super tasty? Super expensive compared to traditional food?
.....

I agree with you on the first point; they're "healthy" foods rather than "super" foods; but no, they're not especially expensive foods. In fact I'm not sure what you consider "traditional" foods. Everybody I know eats many those and grew up eating them for at least as far back as the 3 generations before me that I knew (bananas, tomatoes, spinach, beets) So those foods are "traditional" foods. Some of them only go back as far as this generation (and I refuse to eat alfalfa, that's cattle food) but still, even they aren't particularly expensive.

 

[Janne]

Santa, I stand corrected, yes, many designated super foods ARE traditional. Red beets, kale, kombucha.
I was thinking more of seeds like Chia, Quinoa and similar exotics. Even Sweet potatoes. Very exotic where I originate from!

The sad bit is that people think they will give them a longer, healthier life, due to a higher concentration of minerals/ vitamins/ whatever.

The truth is that our bodies take what it needs, and excretes the rest. Sometimes damaging the organ in question if taken in excess.
Today very few individuals in the Western world are suffering from problems and diseases stemming from malnutrition. No, we suffer from over nutrition.


I love kale. Not because it is healthy, but because it has a flavour I love. I love all veg. The only veg that will not pass my lips is broccoli! I have never tried alfa alfa.

When I grew up, we only had traditional European veg. Seasonal. Plus stored carrots and sauerkraut.

 

[Janne]

As I wrote earlier, I loove blood based foods. French, Czech and German blood sausage, Swedish and Norwegian blodpudfing, British Black Pudding.
Love them!

But, one Kåsa of fresh, warm bloid made me puke. Not just me, all of us. Not the taste. Not the fact that the animal was dying.
It was the affect of the coagulation of it inside our stomachs.

In a survival situation, where water was scarse and the blood was drunk for hydration, this would be devastating.
Instant, massive dehydration.

Also, there is a risk of a mild infection with a stomach bug if you eat raw animal.
So, a risk for diarrhea. Another massive dehydration.

So, in a worst case scenario, you can gt a more or less fatal dehydration by drinking blood.

If my son asked me about drinking raw blood, I would say "no, cook it. Cook it with the stomach content"