You can’t eat just any leaf (2018)

https://www.urbo.com/content/this-is-why-you-cant-eat-just-any-leaf/

by moviewise • 4 years ago

84 118 4 years ago

urbo.com

h2odragon• 4 years ago

Sure you can. You just might not be able to digest it, or the process might be unpleasant to fatal.

Take the hound approach: decide "edible" on best of 3 trials.

dredmorbius15• 4 years ago

You can't read just any grey-on-white text.

chrispine• 4 years ago

For real.

Also, why are some of the links struck-out?

jacobr12• 4 years ago

That bothered me too. Trying a few though, it looks like they are 404s. Which is an interesting way to preserve a historical, but no longer valid link. If you are going to the trouble, it might be better to rewrite the links to point to Archive.org or something.

kroltan• 4 years ago

Because they are broken, apparently. The CSS class for those is `broken_link`, and I tried on the "Primary and secondary compounds", sure enough it leads to an "access denied" response 403.

dang• 4 years ago

"Please don't complain about tangential annoyances—things like article or website formats, name collisions, or back-button breakage. They're too common to be interesting."

https://news.ycombinator.com/newsguidelines.html

dredmorbius15• 4 years ago

I'm aware.

This site takes it to the next level, and is honestly illegible. I'd hope that at some point extraordinary badness is remarkable.

Something's got to give, and I'd suggest here it's the HN guidelines.

aaron6952• 4 years ago

If you have browsers/grazers this is a nightmare.

A lot of mis-information on the internet. Even more unknowns.

You can't even assume if it doesn't kill one species it won't kill another. Sometimes it's age of leaves. If they are for meat, something's won't matter short term, but are bad long term for pets.

What's interesting is you can sup up cows with a rumen bacterium Leucaena inoculum which has skyrocketed productivity on some places. This goes from harmful to productive - https://www.youtube.com/watch?v=8wj14UNTKpo

It's not the only rumen bacterium that works either, there is Fibrolytic rumen but you can't buy it yet, you just mix camels with cattle so they share it at drinking locations.

I think this would be interesting to hack in humans. It'd be nice to eat grass occasionally.

nielsbot• 4 years ago

Wouldn't you need a rumen to make it work tho?

Maybe you could make some kind of bioreactor and eat from that... Appetizing!

maxerickson• 4 years ago

Historically, humans have used cattle (and other ruminants) to digest cellulose.

aaron6952• 4 years ago

It's thought we can digest some cellulose already. And there's no reason to not think we couldn't increase that.

For the general population digesting more fibre would bad, but to be able to eat leaves and grass for a while would be interesting.

Humans have intestinal bacteria that degrade the plant cell walls in herbivores https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8661373/

superb-owl• 4 years ago

I've been wondering about this in the context of supply chain disruption and food security. I live far from farmland and fear what might happen if that connection were cut due to war or civil strife.

How well could I survive eating local plants and whatever I can grow? How well could what we have nearby support the local population? Resources like the ones mentioned here could prove lifesaving.

fny• 4 years ago

You can't. We have not engineered life to work this way.

eru10• 4 years ago

It's not a binary thing. There's graduations.

swagasaurus-rex• 4 years ago

Maybe it's not a bad idea to keep a cellar of canned, non-perishable food and water stored in containers that do not leech.

You would want to replace the stockpile every few years so it doesn't spoil.

jefftk3• 4 years ago

Instead of a stockpile you replace every so often, it's a lot cheaper to just buy extra of the long shelf life things you use. Instead of keeping one jar of peanut butter, you have ten (or however many you'll reliably use before they go bad).

_eht• 4 years ago

Something to also consider is how you would protect your supply (and children) from your less prepared neighbor and former friend, Alex Jones.

phyzome7• 4 years ago

Rather than canned goods, prefer dry goods. In our basement we have 5-gallon buckets of lentils, chickpeas, millet, sunflower seeds, pepitas, and various other things. (Also cases of peanut butter, jarred tomatoes, various flours and such.) This isn't hoarding -- these are things we use! But we always make sure to reorder before a container runs out, which usually takes 6 months to a year.

When the pandemic hit, we just bought another 25 lb bag each of lentils and millet and called it good.

jacobr12• 4 years ago

I've seen difference estimates, but you need ~5 acres of land to feed one person for a year with a balanced diet. Intensive farming can reduce that if you focus on monoculture grain crops. Meat increases the land need. A backyard garden and local foraging doesn't cut it. And if you are feeding a whole community ... you need a lot of land.

tipoftheiceberg• 4 years ago

Vertical indoor farming is the paradigm shift we’ve been waiting for. Thanks in part to advances in LED lighting efficiency and cost. Much more land and water efficient.

voisin2• 4 years ago

I've seen difference estimates, but you need ~5 acres of land to feed one person for a year with a balanced diet.

Check out “The Market Gardener” by Jean Martin Fortier. The quoted statement is a myth. Farms historically were nowhere near as large as today and we able to provide a balanced diet to those literally on the same block (think “in-fill market gardens”)

phyzome7• 4 years ago

That estimate seems more than a little high!

It depends on what you mean by "balanced diet" (are you going to require meat?) but let's just work an example with sweet potatoes, which are pretty nutritionally packed and can be ludicrously productive.

Let's say you planted just one acre over with sweet potatoes; you could grow roughly 5 tons of usable roots, about 10,000 kcal/day. Swap some of that area out for other crops for nutrient balance and you'd still have a huge excess for one person, even accounting for a farmer's caloric needs. You might also end up hating sweet potatoes after a year, but that's why you specialize in a few calorie crops and then trade with others for what you need.

Anyway, it seems to me that an acre would be more than enough for a whole family.

dragonwriter• 4 years ago

I've seen difference estimates, but you need ~5 acres of land to feed one person for a year with a balanced diet.

If it's one year’s output of that land to feed that person for a year, then it's just 5 acres for a person (and you can drop of then “for a year”, since the output period matches the consumption period.)

mythrwy• 4 years ago

You could feed a person off less then half an acre in regions with a decently long growing season. Even could support a few chickens.

The above is true with some qualifications. You will need decent soil and plentiful clean water. And a power source to pump the water. And fertility which you will have to bring in. The compost you make won't do it. A way to control pests, (ya ya muh organic, but we are trying to survive here). So some pesticides. Sprayers. More then one, they break. Maybe some herbicides as well so you don't burn so many calories hoeing. Some mechanical help like a rototiller will make this much more possible. Fuel oil and parts for that. Some fencing and trellising. Bird netting. A way to preserve harvests like canning, drying or freezing.

Most importantly (and most people will lack this rendering half an acre vs 5 acres moot for practical purposes) you will need a fair amount of expertise to pull it off. Generally from experience. And it will be a lot of work and mostly unforgiving of mistakes.

Source: I mostly made it up, but I am an agronomist and long time gardener. It's probably roughly right though.

carapace• 4 years ago

These folks: http://growbiointensive.org/grow_main.html have a system that produces a complete diet in 5000 ft² (465m²) per person. It also produces its own compost, so that the farm increases soil volume and fertility year-on-year too.

(Their server seems to be slow tonight, check out this for a summary of their system: https://web.archive.org/web/20210411002519/http://growbioint... )

dredmorbius15• 4 years ago

It would be exceedingly challenging.

It's probably best to think of supplementing rather than replacing external food supplies and sources. Raising perishable / vegetable crops and having a source of protein (fowl -> eggs, goat -> milk) would probably be your best bets.

You'd need to spend an extraordiary amount of time preserving harvest: drying, salting, smoking, curing, fermenting, and canning.

On a per-acre and per-hour basis, potatos are probably your best bet. A carb-heavy diet will tend to add pounds.

The traditional native American crops were the Three Sisters: corn, beans, and squash:

https://www.almanac.com/content/three-sisters-corn-bean-and-...

These are mutually symbiotic (the beans add nitrogen to the soil, I believe there's some pest-management aspect to this as well).

Preindustrial communities also relied heavily on fishing and shellfish --- another iconic pattern are shell mounds, literally the remnants of shellfish eaten. (See Shell Mound Road in Emeryville, as an example, in the SF Bay Area.) Grazing livestock was another standard.

Note that the native population of regions such as the Los Angeles basin may have been a few thousands, and for pre-Columbian North America (including Mexico and Central America) roughly 50 millions.

HWR_14• 4 years ago

These are mutually symbiotic

The squash creates a dense ground cover that clogs out weeds. The beans add nitrogen. The corn provides a trellis the beans can grow up.

ClumsyPilot4• 4 years ago

You'd need to spend an extraordiary amount of time preserving harvest: drying, salting, smoking, curing, fermenting, and canning.

back in soviet times, we didn't have 365 day a year avaliability of fruit from another side of the planet, and our grandmother used to can hundreds of kilos of fruit and veg in the summer. She would fill up a storage room and that wouod supplement our diet in the colder months.

Its quite a bit of work, like a week or 2, but was normal withing living memory. Also you need equipment: a canning machine, and like 30+ 5-liter glass jars. And this is just one aspect of what you would need.

ravenstine• 4 years ago

How well could I survive eating local plants [...]?

I don't recommend this. As someone who has been foraging for over a decade, I believe you are much better off stockpiling food, learning to raise chickens, owning some fishing gear, maybe growing your own crops, and even learning to hunt small game.

Here's my educated opinion:

Foraging is fine as a sort of hobby or interest, but most people shouldn't consider it for survival and the vast majority of people have no business doing it at all. That might sound extreme, but trust me. I've witnessed so much stupidity in foraging communities, online and offline, that I completely gave up participating. Having to constantly correct bad and even dangerous advice got really tiring.

Being good at ID'ing and using plants requires adequate time spent gathering knowledge and experience. Most people won't come close because they don't have the interest.

Many people just don't have the visual processing skills. Foraging is a very visual skill. Some people have it. Foraging came natural to me because I'm highly visual. I can ID things very easily after an experience. Others I've known are nearly incapable of ID'ing plants reliably. I'd say at least half of people are not good at ID'ing and probably never will be without some app on a phone connected to the internet.

Foraging is and historically has been tertiary to hunting and agriculture/livestock. Most wild plants simply don't have the energy density to justify the energy spent to collect and eat them. Those that are energy dense are usually only around for a few months out of the year and still may not be that plentiful.

At best, foraging is a stopgap while crops are growing. I'd love to say that it's practical merely live off the land, and while I think I might be able to get away with it longer than the average person, it's just not viable for most.

EdwardDiego3• 4 years ago

And also, Hunting & gathering/foraging will only support a far smaller population than our current agriculture based society.

So sure, you can live off foraging alone. When everyone else is not.

But when _everyone_ starts hunting and gathering you'll quickly realise how far agriculture has displaced us from the basic carrying capacity of the land, and then move onto the realisation of what happens in nature when the population of an animal exceeds the carrying capacity of their territory.

Starvation, conflict. Nothing great.

That's the problem with post-apocalyptic day dreams, they usually posit you as one of the few survivors. In reality, there'll be way more other survivors, either competing with you for resources, or, if you have a sweet bunker filled with supplies, forming a coalition that can overcome any advantage you have in firepower, by sheer numbers of desperate people.

(Peter Thiel take note, if the apocalypse comes, you can't shoot every Kiwi, and we're mighty interested in what's in your bunker. #AotearoaIsNotYourLifeboatRichPeople)

undersuit2• 4 years ago

I have 7 chickens on .24 urban acres. I'd definitely have to convert most of the 'land' to chicken feed if in an apocalyptic scenario but having 2-5 eggs a day is a wonderful blessing.

ls152• 4 years ago

How well could I survive eating local plants and whatever I can grow?

Most likely not engough calories, but for growing your own greens in order to complement stockpiled food, I would recommend looking into passive hydroponics ("Kratky method"). It's easy, cheap and fun and it can provide a small constant supply of fresh food.

not2b• 4 years ago

For Californians: miner's lettuce (Claytonia perfoliata). Good stuff, similar taste to spinach. It grows all over in late winter and early spring.

bawolff• 4 years ago

Interesting premise for an article, but i was hoping for something a little deeper than - some leaves lack nutritional value (as being almost entirely fiber) and some leaves are poisonous.

pessimizer• 4 years ago

It's debunking something nobody has said ("You can eat any leaf.")

edit: Of course, they seem to be aware - "It sounds like a simple question, the work of a 6-year-old or a general interest reporter short on ideas."

eru10• 4 years ago

Lacking nutritional value might not be too bad. I guess, it's better to munch on those than eg eat potato crisps? (Assuming your are otherwise getting your nutrient..)

You are rightly worried about poison.

newaccount74• 4 years ago

I agree, it's a very shallow article. Would have loved something more in depth.

chanandler_bong2• 4 years ago

Anything is edible, at least once.

istjohn• 4 years ago

Counter example: boulders

cowtools• 4 years ago

depends on serving size

fsckboy• 4 years ago

it's not easy but you just need to grind them very finely and then eat the sandwhich results

chanandler_bong2• 4 years ago

True, you can't eat a cow, but you can chop it up in to smaller pieces.

seveneightn9ne• 4 years ago

Pine needles may be calorie-negative and unpleasant to eat, but they're very high in Vit C and available in the dead of winter. I would hardly call them inedible. You can make an oxymel to extract the vitamins & make it easier to eat.

dredmorbius15• 4 years ago

Or brew them as a tea.

The fresh shoots don't taste all bad. Definitely bitter, but not in an unpleasant way.

cainxinth• 4 years ago

https://en.wikipedia.org/wiki/Spruce_beer

echelon• 4 years ago

Transgenic edible plants would be incredible, introducing entirely new species and flavors to the palate.

Cellulose isn't the problem. Just the toxic and bitter organic compounds. Knock out a few genes and it should work. These genes shouldn't be necessary for plant growth.

eru10• 4 years ago

Just the toxic and bitter organic compounds. Knock out a few genes and it should work. These genes shouldn't be necessary for plant growth.

Maybe; but on the other hand, genomes aren't cleanly engineered.

phyzome7• 4 years ago

At my house, we've largely given up on growing "greens" because there are so many edible and tasty weeds that come up all on their own without any help. Our mainstays are chickweed, broad-leaf plantain, violet, dandelion, and lamb's quarters but there are a ton of others (amaranth, galinsoga, dock, burdock...) -- and it's worth noting that many of these were actually brought over by European colonists or were cultivated by Native Americans. They're just thought of as weeds today, but they make a fine salad.

Many of these would be bad to eat in large amounts, but humans are "generalists" -- we're built to eat smaller amounts of a variety of things together. The same is true for a number of our modern cultivated crops; off the top of my head the things in the mustard, spinach, and carrot families are mildly toxic, but we eat moderate amounts of each, so it works out.

carbadtraingood3• 4 years ago

Borage, miner's lettuce, nettle too! To say nothing of the berries you can snag from things.

That said, we do grow kale, as it's a pretty nutrient dense green that is mighty tasty, versatile, and hard to mess up.

bergenty2• 4 years ago

This entire article could have talked about only oxalic acid and it would be a better article. It’s basically what all plants have to make themselves largely inedible and it the most common toxin in plants. You can eat all of the above but oxalic acid is just not good for you even small quantities. We’ve managed to get oxalic acid out of everything we’ve domesticated.

mulvya2• 4 years ago

oxalic acid is just not good for you even small quantities. We’ve managed to get oxalic acid out of everything we’ve domesticated

Doesn't sound right. WP has this table: https://en.wikipedia.org/wiki/Oxalic_acid#Content_in_food_it.... I see a lot of commonly eaten foods with at least a small amount of it.

undersuit2• 4 years ago

Is that why I hear about stories of people eating too much spinach or drinking too much tea and getting mineral stones that form from oxalic acid?

phyzome7• 4 years ago

You're correct that many of those things have a lot of oxalic acid, but that domestication often reduces it -- but quite a few of our domesticated crops still have a large amount. We haven't gotten rid of it! The spinach, brassica, and carrot families are high in oxalic acid and/or oxalates, as are a bunch of fruits. And rhubarb is absolutely loaded with it, of course. All things to avoid if you have a family or personal history of kidney stones...

The other big toxins that come to mind are cyanogenic glycosides, lectins (improperly cooked kidney beans can kill!), and phytic acid. Those are well represented across a huge number of domesticated crops. But again, we use cooking and/or moderated consumption to deal with it.

EdwardDiego3• 4 years ago

I'm a big fan of chickweed, but also shepherd's purse, its seed pods have a delightful mustard taste

wyager• 4 years ago

Spinach hardly qualifies as edible. It has essentially no nutritional value, and is poisonous/anti-nutritious due to its oxalic acid content.

Most leaves are this way. The plant doesn't use them for energy storage, doesn't want animals to eat them as part of its reproductive strategy, and actively benefits from discouraging animals from doing so.

hombre_fatal• 4 years ago

We are regularly wrong when we try to come up with first principles when trying to make assumptions about nutrition.

Even "lectins must always be bad" turns out to be wrong.

You don't necessarily complete the circle here, granted, but I've heard it claimed many times lately by Twitter carnivore-diet influencers that plants must be bad for you because they don't have claws/teeth thus they depend on chemical deterrents.

It's a very arbitrary attempt at a first principle, not the least of which because it seems to suggest that we are incapable of even the most basic nutrition science.

citizenpaul2• 4 years ago

Spinach is by a huge margin the most dense source of magnesium. Magnesium is needed for muscle growth and rebuilding. Its one of a number of nutrients that is usually under provided in supplements because it makes the pills too big and people don't like large vitamins. You'll see things like 10000% of vitamin A but the multivitamin will have like 5% for magnesium.

downboots• 4 years ago

Related: This one has extensive videos foraging and cooking many plants https://youtube.com/user/EatTheWeeds

tedunangst• 4 years ago

The same for meat? My neighborhood is teaming with uneaten squirrels and pigeons and creepy crawlers.

eternityforest• 4 years ago

What happens if people do eat the indigestible leaves? They might not get any calories from it, but people have more than enough of those already in the developed world. What's the difference between a leaf full of cellulose and something like psyllium husks?

Do people get nauseated if they have too many large pieces of leaves(I would imagine so, but I've never eaten random leaves so I don't know)? What about the various chemicals in them? There's gotta be at least chlorophyll and probably some other active stuff, right? What do those do if you eat them regularly? Are any of them beneficial?

ghostly_s• 4 years ago

what's up with the random crossed-out links in the article? I clicked a couple and they don't seem to be dead.

akovaski• 4 years ago

"Primary and Secondary compounds" => 403. "medicinal" => 200. "Monoculture leads to vulnerability" => 404. "Leaf for Life" => 404.

And the "medicinal" link to science direct returns a 403 if I attempt to retrieve the page with curl.

So, the sites are still up, but the links are in fact mostly dead.

togaen• 4 years ago

Light gray text on white background??? What kind of maniac designs a web page like that?

jononomo3• 4 years ago

I did not consume a single calorie from a plant-based source in 2021 and I ended the year in the best shape of my life. It is astonishing how much more nutritious animal-based foods are in comparison to plant-based food.

failedengineer2• 4 years ago

Are you consuming entire animals? Just meat? No snark there, either. Skeletal muscle alone isn't a complete diet. It's lacking in a few areas. Eating nothing but meat does seem to improve body composition, insulin sensitivity, some autoimmune conditions, some people report more steady energy levels... but, scurvy is eventually a problem, as will be hemochromatosis, among other things.

jononomo3• 4 years ago

This couple has eaten nothing but ribeye steaks for over 20 years: https://www.ketoforhealth.org/articles/150-joe-and-charlene-...

Can you tell me what areas this diet is lacking in? Scurvy is not a problem because fresh meat contains vitamin C. And hemochromatosis is not a problem either. It sounds to me like you're just hypothesizing here. In fact, people have known for centuries that fresh meat prevents scurvy.

ComputerCat• 4 years ago

The evolution of plant defense mechanisms is so fascinating. Thanks for sharing!

abeppu• 4 years ago

The sad truth is that people just can’t digest cellulose. We lack the enzymes.

Can we/should we try to add the enzymes?

Some time back I recall an adventurous citizen scientist that did DIY gene therapy to add back his ability to digest lactose, and I think he even used a bacterial enzyme for reasons I don't recall. I think a bunch of more knowledgeable people called this reckless, but it seemed to work. Could we give ourselves a gene to break down cellulose?

You can’t eat just any leaf (2018)

Related Stories