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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?

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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
    Commented Nov 13, 2017 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.
    – user14347
    Commented Nov 14, 2017 at 0:00
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    Do humans eat the stalk of the corn or wheat?
    – paparazzo
    Commented Nov 14, 2017 at 4:39
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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
    Commented Nov 14, 2017 at 13:40
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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. Commented Nov 14, 2017 at 16:11

7 Answers 7

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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.

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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... Commented Nov 13, 2017 at 16:38
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    mmm, delicious destroying angel Commented Nov 13, 2017 at 16:52
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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
    Commented Nov 13, 2017 at 18:42
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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
    Commented Nov 13, 2017 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. Commented Nov 14, 2017 at 7:09
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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.

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    Comments are not for extended discussion; this conversation has been moved to chat.
    – Rory Alsop
    Commented Nov 15, 2017 at 9:52
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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.

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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
    Commented Nov 16, 2017 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.

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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.

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    Are grasses more likely to transmit these then any other plant one might consume in the outdoors? Commented Nov 14, 2017 at 15:22
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    @JamesJenkins I'm pretty sure that it is so. 1) sheep get them from the grass (said my grandpa, who was a farm vet for 50+ years) and 2) the eggs cling to the stuff they are excreted on, even after the initial heap of dung is no longer visible. Most mammals don't excrete on fruits and nuts over a certain height, and humans are not as susceptible to bird parasites (less evolutionary similarity). 3, you can peel nuts and most fruits, you can't peel grass.
    – rumtscho
    Commented Nov 14, 2017 at 15:27
  • Would washing and/or cooking the grass remove the danger? You can peel grass See this comment "you can firmly but very carefully pull one of the inner tubes out of the outer tube, and chew the pale-coloured end" Personally I have chewed peeled grass for decades. Commented Nov 14, 2017 at 15:39
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    I don't know about cooking, I have no idea if anybody has published safety data on wild nonedible plants. As for the peeling, I may have been thinking of different types of grass (blades) than you do.
    – rumtscho
    Commented Nov 14, 2017 at 16:25
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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.

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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.

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