61

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?

| improve this question | |
  • 9
    +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
  • 12
    @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 Nov 14 '17 at 0:00
  • 9
    Do humans eat the stalk of the corn or wheat? – paparazzo Nov 14 '17 at 4:39
  • 3
    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
  • 4
    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
86

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.

| improve this answer | |
  • 7
    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 Nov 13 '17 at 16:38
  • 4
    mmm, delicious destroying angel – Wayne Werner Nov 13 '17 at 16:52
  • 5
    @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
  • 74
    @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
  • 27
    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 7:09
24

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.

| improve this answer | |
  • 1
    Comments are not for extended discussion; this conversation has been moved to chat. – Rory Alsop♦ Nov 15 '17 at 9:52
  • Also: tons and tons of parasites and pollutants. The same reason humans avoid e.g. raw pork. – Luaan Nov 16 '17 at 13:35
16

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.

| improve this answer | |
16

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.

| improve this answer | |
  • 1
    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
10

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.

| improve this answer | |
  • 3
    Are grasses more likely to transmit these then any other plant one might consume in the outdoors? – James Jenkins Nov 14 '17 at 15:22
  • 1
    @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 Nov 14 '17 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. – James Jenkins Nov 14 '17 at 15:39
  • 1
    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 Nov 14 '17 at 16:25

Not the answer you're looking for? Browse other questions tagged or ask your own question.