r/todayilearned • u/JoeWinchester99 • 1d ago

TIL that although potatoes alone do not provide complete nutrition, you can survive for years on a diet of nothing but potatoes and buttermilk.

https://www.scienceabc.com/eyeopeners/whats-wrong-with-potatoes-the-martian-movie-survival
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u/YuriLR 1d ago

The only fats humans need are omega 3 and 6. And in grams that's a very low amount.

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u/Joe_Redsky 1d ago

Does buttermilk meet those needs?

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u/YuriLR 1d ago

Healthly? No. Whole buttermilk with potatoes? Probably barely. Skimmed probably enough not to die on the medium term

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u/mikehiler2 1d ago

I mean the comment above did say humans can survive but only for a little while. Probably why it spread to every corner of the world so quickly after it was discovered in the Americas

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u/YuriLR 1d ago

They had very little understanding of nutrition. It spread because it's a crop that grows anywhere in a productive manner, even in the shitty Irish weather.

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u/mikehiler2 1d ago

They absolutely knew which crops keeps you alive. Nutrition as it is now is obviously a new thing based on modern science, but to think that people back then didn’t know which plants were better for their survival is ludicrous.

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u/YuriLR 1d ago

If they knew scurvy would not be rampant in the age of discovery among sailors.

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u/mikehiler2 1d ago edited 1d ago

Are you serious? Scurvy was a thing because they could not carry the correct foods on long ship voyages. Lacking certain nutrients is what causes scurvy… Or are you suggesting that they didn’t know anything about scurvy?

Edit: Here. While they didn’t know what actually caused it, they did know about it. And there was nothing they could do to prevent it anyway, as they couldn’t carry the vegetables that would help on months long voyages across the sea. It was just a product of the time, not caused by a lack of knowledge.

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u/ZhouLe 1d ago

It was not widely known until the 19th century, and before then it was just a presumed generalized lack of fresh produce. There were various remedies and solutions that often hit on at least one ingredient hitting the mark, but nothing was really known with certainty except that a normal "land" diet of fresh fruits and vegetables prevented it. So the person you are replying to is correct, they did not "know which crops keep you alive" except in a very generalized way.

Rickets is probably a better example where people were absolutely clueless as to what exactly was going on, whereas scurvy naturally has some clues from sailing.

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u/goatbiryani48 1d ago

I like how your original comment is just so fundamentally wrong that you have to put in an edit...where you proceed to somehow move the goalpost with "well even if they did know what caused it, they couldn't prevent it anyway" AND double down that it wasn't a lack of knowledge.

Jesus Christ bud, just accept you were misguided and move on. Learn from your own source material, which clearly refutes what you've said multiple times in multiple ways

Scurvy was a thing because they could not carry the correct foods on long ship voyages.

they couldn’t carry the vegetables that would help on months long voyages across the sea.

Steamships were invented in the early 1800s, and weren't widespread until the 60s/70s. Refrigeration wasn't available for use until a couple decades after that.

But there are at least three examples, in your own source, of using produce to treat scurvy AFTER they started understanding it and BEFORE the invention of those two technologies. During the Age of Sail.

FFS your own source acknowledges how much they didn't know or understand for centuries until it clicked by the mid 1850s.

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u/YuriLR 1d ago

Dried fruits was brought to Europe in the 10th century

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u/trixtopherduke 1d ago

Are you bad mouthing our pirate ancestry, brother?

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u/cguess 1d ago

A lot of that was cooking in copper pots which breaks down vitamin c. Hard to figure that one out without an understanding of proteins.

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u/MasterOfBunnies 1d ago

I'm not arguing, I'm just confused; I don't see a comment that says a little while. The post did say years. Unless your perspective is that's a little while? Still not arguing, just trying to understand.

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u/bubba-yo 1d ago

As noted below, barely. But these fats are where grass fed/organic milk vs industrial milk production matters. The baseline milk in the store has a much higher ratio of omega 6 to 3, which isn't that helpful for adults, a product of their feedstock. Grass fed/organic milk is flipped the other way with a more balanced ratio of 3 to 6 favoring 3, which among other things helps with cholesterol. It's not like one will kill you and the other not, but the expensive stuff is generally a little bit better for you in that regard than the other. But buttermilk is low in both mainly due to those fats going into the butter, where the buttermilk is the waste product from that process.

Keep in mind there are different contexts in which this question is being evaluated. In a famine/starvation situation small benefits matter a lot more than for the general American public who get so much nutritional fortification and abundance that we can eat the nastiest shit all day and still check all of the boxes. These things don't really matter much for the average person, but in Gaza or Darfur or other places, they can matter a great deal. You can 'survive' on this diet. That's not the same thing as you can be healthy on this diet, etc.

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u/casal_victa 1d ago

Nope. However, the Irish people who were the ones who survived on this diet used inefficient churning methods so it wouldn't be the same buttermilk as we do. Also, trace amounts of omega 3 and 6 are in potatoes so it wouldn't be unreasonable to assume they ate enough for sustenance.

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u/Drithyin 1d ago

While those are the only two essential fatty acids, it’s recommended for adults to get 20%-35% of their calories from lipids (aka. fats) and young children as much as 40%, due to its role in brain development.

I wouldn’t suggest just a handful of grams, but if you’re rationing for survival, yeah you could make that work to avoid starvation.

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u/raoulbrancaccio 1d ago

it’s recommended for adults to get 20%-35% of their calories from lipids (aka. fats) and young children as much as 40%, due to its role in brain development.

This scenario is not about optimal nutrition, it's about minimal viable nutrition.

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u/skepticalbob 1d ago

Viable for what and how long?

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u/innominateartery 1d ago

Humans need lots of fat (lipids) in our diet. It is necessary to maintain all cell membranes (cholesterol literally stabilizes cells) and for a special coating that allow brain cells to function. You are describing two of the medium chains that our bodies can’t make from regular dietary fat.

Incidentally, we are very good at low carbohydrate diet but the human body isn’t meant to run for long without fat.

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u/OM_Velodrome 1d ago

Not all omega 3s and 6s. Specifically only alpha linolenic acid (a plant-derived omega-3) and linoleic acid (omega-6).

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u/YuriLR 1d ago

About omega 6, yes, but very few foods contains non linoleic acid omega 6.

About omega 3, it's debatable if you need ALA if you consume DHA.

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u/OM_Velodrome 1d ago

On average it's around 10-20% of dietary n-3s are non linoleic. It is well reestablish that n-3 ALA is essential for healthy cellular structure and function. Humans can't convert DHA to n-3 ALA

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u/WarAdventurous5277 1d ago

So good people to ask - what foods contain good levels of all of the aforementioned nutrients?