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A recent comment

Cows eat grass, doesn't mean you can!

got me thinking. Corn, wheat, rice, etc are all grass that we eat regularly. I am not sure the human race could survive on the planet without eating grass.

But in all fairness, for the most part humans only eat the grains of the grass.

Can I eat the other parts of the grass also?

If yes, what do I need to know and/or do to prepare the grass for eating?

James Jenkins
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    +1 because this is a very important issue in our society. If we could figure out how to straight-up eat grass like other animals, then there would be many fewer starving people. I have been thinking about this for years, and I've always wondered why we don't hear more research about developing techniques to process grass (not just seeds) or to genetically modify people to develop enzymes to at least somewhat digest grass. – kloddant Nov 13 '17 at 23:46
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    @kloddant or far more likely: There would be no grass in less than a generation. Then someone would need to plant more. Replacing crops still means the need to grow those crops, then the issues remains the same, just a different plant. –  Nov 14 '17 at 00:00
  • I agree. If more people thought like you, the world would be a better place. – Caleb Way Nov 14 '17 at 00:06
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    Do humans eat the stalk of the corn or wheat? – paparazzo Nov 14 '17 at 04:39
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    Since I don't have enough rep here I can't answer, and I'm not sure if it's substantial enough for an answer anyway, but you can chew on grass shoots and it can be quite tasty. I don't swallow them, but if you find the larger pieces of grass that seem to be tubes inside tubes, you can firmly but very carefully pull one of the inner tubes out of the outer tube, and chew the pale-coloured end. – Muzer Nov 14 '17 at 13:40
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    There is no point of eating grass like cows, our stomachs can't extract energy from cellulose like cow stomachs can. All you will get is some fiber at best. At worst, you will get food poisoning. – FailedUnitTest Nov 14 '17 at 15:25
  • @FailedUnitTest you know cane sugar comes from grass? – James Jenkins Nov 14 '17 at 16:04
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    Sugar cane grass is a bit special in that it has a lot of sugar. But, sugar on its own gives us very little, we cannot survive on it. Cows are able to get all kinds of nutrients and far more energy from grass because their stomachs are able to breakdown rich cellulose. – FailedUnitTest Nov 14 '17 at 16:11
  • "Back in the day" when our Appendix was not atrophied (or vestigial) it might have served us a purpose: digestion of cellulose - which could have enabled us to meaningfully consume grasses. Nowadays, however, it serves no function to us (that we know). – PCARR Nov 14 '17 at 17:37
  • Eat less than 1,500 pounds in 15 minuets and you're all good. – Mazura Nov 17 '17 at 00:38
  • How about if you pull the grass, mash it up a bit, put in a jug with a bit of water, and let it ferment. Then drink the liquid? – Hot Licks Nov 19 '17 at 03:38
  • @HotLicks It is possible but not easy to make Cellulosic ethanol it is not as simple as adding water to grass, if it was we would be using it for fuel. – James Jenkins Nov 19 '17 at 12:05
  • Radika is an extremely delicious dish from Izmir, Turkey. We call it Radika I don't know what people call it in English and I never had problems with either digesting nor contamination. It's a wild plant and people collect it from mountains. This is a photo of Radika dish: http://1.bp.blogspot.com/-5GEzFieJLpU/UmgPavZ0XwI/AAAAAAAABgo/YpgHYJCcDnE/s400/DSCF4518.JPG – ferit Nov 19 '17 at 17:24
  • Not an answer to your question, but there is a very good SF story -- dates from maybe 30 years ago -- titled "No Blade of Grass". By one of the era's greats, although I can't remember who. Civilization collapsed when all grasses died. This is slightly wrong. The story was The Death of Grass and the movie was No Blade of Grass. For review of the movie, see https://diaboliquemagazine.com/unrelenting-bleakness-no-blade-of-grass-fifty-years-later/ – ab2 Jan 04 '23 at 23:12
  • @kloddant says "If we could figure out how to straight-up eat grass like other animals, then there would be many fewer starving people." — Only briefly. Dave Smeds published a short story on this theme in 1987 (IASFM), "Termites". People in Africa were made able to digest cellulose so that they could subsist on grass, plants, and even wood. The result was inevitable, and should have been obvious. The people prospered for a while, multiplied, then ate all the forests, and Africa was destroyed (I think perhaps with the Sahara taking over the whole continent.) And oh yeah, everyone dies. – Ray Butterworth Jan 07 '23 at 00:47

7 Answers7

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Just because there are grasses (Poaceae) with edible and nutritious parts does not mean that this applies to all grasses. That is pretty common-place.

A quick Google search give you all the info you need:

Many grasses are edible, in the sense that you can eat it; you simply won't get any energy/nutrients out of it. They consist mostly of cellulose, and our digestive tract is simply not made to break that down (as opposed to, e.g. cows, which employ four stomachs for that purpose). There are however also grasses that are toxic. So when not discerning between actual species, the effect of eating grasses is somewhere between no effect and harmful.

imsodin
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    If you (reader) are still not convinced (that not all grass are edible), replace "grass" with "mushrooms" in this page. Except maybe the cellulose and cow part... – Mindwin Remember Monica Nov 13 '17 at 16:38
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    @Mindwin: Not quite the same, as the mushrooms are actively poisonous, while AFAIK few if any grasses are. I certainly have survived a number of decades of pulling up grass stems and chewing on the ends while walking through meadows... – jamesqf Nov 13 '17 at 18:42
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    Even though we can not get energy/ nutrients out of grass, we could still benefit from it as dietary fiber, I guess. https://en.wikipedia.org/wiki/Dietary_fiber – Arsak Nov 13 '17 at 19:00
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    @imsodin OP asks about possible special preparation methods. While eating common grass directly might not provide benefit, what if you boiled the grass, perhaps for tea? Do you know if the cellulose would break down into something digestible? – Loduwijk Nov 13 '17 at 20:19
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    You can also have problems with things growing on the grass. E.g. ergot poisoning from ergot infested rye grass (even though rye would otherwise be safe to eat). Note that it can be difficult to recognize (or even see) fungi on grasses. – user3067860 Nov 13 '17 at 21:31
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    @Aaron, there isn't much that will break cellulose down. The most effective way humans have found is to feed the grass to a cow and then eat the cow. – Mark Nov 13 '17 at 23:02
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    It's not just the cellulose: many kinds of grass incorporate small silica filaments or spines called phytoliths - essentially biological glass shards. Grazing animals have thick lips, stomach lining, and constantly-growing teeth to resist the effects of eating it. Grass doesn't want to be eaten and just because it can't run away doesn't mean it's defenseless. – IndigoFenix Nov 14 '17 at 07:09
  • You can make the answer a community wiki if you want to. – SQB Nov 14 '17 at 11:45
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    @Mark Or sheep. The vegetarian argument of "what if we used all that land for crops?" is true enough for corn-fed beef, but it fails for sheep which will happily graze on land that is unsuitable for arable farming. Almost all hilly areas in Britain are sheep farms. – Graham Nov 14 '17 at 12:36
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    Bamboo is a grass. And harvested as a shoot and prepared right, it is delicious :) – rackandboneman Nov 14 '17 at 20:20
  • "the effect of eating grass..." I'd bold that last phrase, and possibly move it to the top; it sums it up so nicely. – jpaugh Nov 15 '17 at 15:39
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    The fun fact is that even cows lack enzymes to break cellulose down. They have a huge digestive tract for bacteria to live in, and let bacteria do all the dirty job. – polkovnikov.ph Nov 16 '17 at 04:10
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    @Mark Well, the most effective way would probably be some bacteria or yeast or such, which have far lower overhead. Cow products are usually more pleasant, though, and a lot more traditional :P – Luaan Nov 16 '17 at 13:33
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    But what if I cook grass or otherwise prepare it (adding enzymes to break down the cellulose, let it ferment,...)? Just because I want to eat something doesn't mean I need to eat it raw and untouched. – NoDataDumpNoContribution Nov 17 '17 at 09:24
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Eating grass isn't smart because our bodies lack the enzymes to digest it, and because you never know if some animal came along and crapped on it. Don't eat grass.

Caleb Way
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Apart from the low nutrients issue, grass stems are covered in tiny silica spikes, which act as an abrasive on your insides. These spikes are thought to have evolved as a defense against being eaten (Silica in grasses as a defence against insect herbivores:) -- which clearly didn't work in the long run.

But anyway, if you don't have a tough lining like a cow has on its lips, esophagus and stomach, you'll risk feeling sandpapered inside or worse.

Elise van Looij
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    On the contrary, it clearly did work - otherwise grasses without this defense would be far more plentiful, and they aren't. It doesn't prevent a specific blade from being eaten right now, but it certainly does has an advantage. Most adaptations only confer a tiny bonus to fitness - if it makes you 3% likelier to reproduce, it's a pretty darn good adaptation :D – Luaan Nov 16 '17 at 13:38
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To add to the existing answers, depending on where the grass is growing, there can be all sorts of synthetic fertilizers thrown onto it which would be very harmful to humans. You do not want to eat Scott's Lawn Fertilizer.

ClydeTheGhost
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A look through the veterinary literature can show you some further reasons not to just go out and eat grass. Specifically, parasites like liver fluke, different species of tapeworm, and some nematodes can infect humans as well as sheep (or cows, or mufflons, or whatever lives on the pastures where you find your grass).

So, in a real outdoors situation, experimenting with grasses is unwise, even if you are very hungry.

rumtscho
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Grass is a common term with various colloquial forms.

Proper Definition: Any of a large family (Gramineae or Poaceae) of monocotyledonous plants having narrow leaves, hollow stems, and clusters of very small, usually wind-pollinated flowers. Grasses include many varieties of plants grown for food, fodder, and ground cover. Wheat, maize, sugar cane, and bamboo are grasses. Source: Dictionary.com.

Grasses usually have the same general structure. Plants in the grass family have narrow leaves with parallel veins. Grass leaves are called blades and they attach at the nodes. The leaves wrap around the culm before they start to stick out. The part that wraps around the culm is called the sheath and the part that sticks out is called the blade. Grasses have flowers that grow in a structure called a spikelet. The flowers are pollinated by the wind. Once the flowers are pollinated, the seeds form. The seeds are dispersed by the wind, rain, and sometimes by passing animals.

The seeds are what contain the most digestible nutrients of the plant for human digestion. To access those nutrients the seeds need to separated from the chaff surrounding the seed. From there you can cook the seeds like a whole grain (such as brown rice) or mill it down into flour. This part of the plant contains carbohydrates that can be absorbed and turned into sugars that help power cellular function.

The chaff, sheath or hull of the grain as well as the blades of grass are primarily composed of cellulose. This is integral in the plants formation because they are the photosynthetic cells that the plant uses to convert light into sugar energy for its own growth. Cellulose is a fibrous material with limited nutritional value for humans.

For example, corn is within the grass family. When you eat a corn cob, your digestive system can only break down what on the inside of the kernel. So when the corn has passed through your system, you will often see yellow husks in your excrement. These are the indigestible cellulose shells. Those shells are also the hard bits that get stuck in your teeth in partially popped pop corn.

This would occur similarly if you were to consume blades of grass, even if it was milled or boiled to soften it. These cellulose fibers are also not water soluble, so other than the imparting a green color caused by exploded chloroplasts, boiling does not actually have any nutrients dissolved in it. Water is also a critical vehicle in the absorption process, so if it is insoluble in water, it’s unlikely to be absorbed in the small intestine. For a nutritional analysis of this theory, I suggest reviewing the dietary and nutrition of eating Celery stalks.

However, bear in mind that vegetarianism is different from being a grazing herbivore. There lots of other plants that are not grasses, and aspects of plants that are readily consumable for humans. Fruit (apples, tomatoes, etc), vegetables, berries, legumes (nuts), fungi, and starchy roots (potatoes, yukka, etc.) are all bioavailable vegetarian nutrients sources for humans, with precautions taken for potentially toxic varieties.

Eliot G York
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On a foraging walk with an experienced guide two of us asked the guide (we had to insist) whether it was safe to eat grass stems. He did not want to answer, as grass stems do not contain enough usable nutrients to make it useful to eat it, but when pressed he said that no grass in the Netherlands (and likely a very big part of the world) contains poisons or other bad substances for people.
You have to be careful to get clean stems, both of us who asked will pick a big stem out of the verge of a road or path, take of the leaves and chew the inner part because if you have the right one it tastes a bit of caramel.

So yes, you can eat grass but under conditions but it will not keep you from starving. It may add a little in fiber or vitamins if the rest of your diet does not supply that, but as a rule it is not worth the effort.

I have never seen cooking instructions for grass, but I expect that there might be a few around and some might even be nutricious.

Willeke
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