Myth busting – Part 6
Continued from Myth busting – Part 5
Myth: OK, so gorillas might not be a great example, but cows are vegans, they eat only grass all day long, and look how big and strong they get! Clearly, a low-fat, meat-free, plant based diet is the way forward!
Truth: Cows eat an extremely high-fat diet! And they are not vegans!
Yeah this one will really mess with your head! Yes, cows eat an 80% fat diet, through a very similar set up as described in Myth busting – Part 5 for the gorilla. Cows and gorillas are both fermenters, so in some ways cows and gorillas have more in common, from a digestive perspective, than humans and gorillas.
Cows are ruminants, they have multiple digestive chambers inside (you’ve heard ‘cows have four stomachs’ right?) the first of which is called a rumen. When they eat grass and leafy plants, it all goes straight down into the rumen, where the process of ‘rumination’ (hence the genus name, ruminant) begins. Rumination involves bringing the food up and down between the mouth and the rumen, generally four to five times for every mouthful.
A cow’s rumen is an amazing thing. This fact blows my mind: in a single cow’s rumen, there are more bacteria then there are human being’s alive on the whole planet! Boom! Mind blown!
And on top of all that bacteria, there are billions of protozoa and digestive enzymes too, and this is still only in the first of the cow’s four major digestive chambers. Traditional tribes used to understand that the lining of a cow’s rumen is so nutritionally dense, they would kill a cow and eat the rumen lining, throwing the muscle meat to their dogs. Yes, they ate the organs and stomach lining and gave the sirloin steak and fillet steak to their dogs!
When you see cows ‘chewing the cud’ they are ruminating…bringing the cud up to give it a chew (mechanical breakdown for all those tough fibrous plants) then sending it back down to the rumen to be soaked in ‘bacteria and protozoa soup’ for chemical breakdown. By the time the food leaves the rumen and passes into the next stage of the digestive system, it’s reduced to a liquid pulp which the digestive enzymes in a cow’s intestines can then extract masses of VFA’s, volatile fatty acids, from. Basically, fats. These form 80% of a cow’s diet by calories, and they are the ruminants’ principle source of energy. Sheep are pretty similar.
So cows and sheep eat a high fat diet, fact. Grass isn’t carbs, not carbs the cow can use for energy. Grass is fibre, that converts to VFAs, fats. There’s your high-fat diet, right there. And just like the gorilla, cows are big and strong because they can synthesize all the amino acids they need from the food they eat, so that covers their protein needs.
Now, you can see what I am talking about when I say that I think Mother Nature designed ruminants as a way to up-regulate the sun’s energy into a food we can use. See, all life on Earth is powered by that enormous nuclear reactor in the sky, beaming down glorious sunshine on us every day. We cannot eat grass or leaves, yet they cover much of the earth’s land surface, absorbing an enormous percentage of the sun’s life-giving energy. I think Mother Nature made ruminants to eat the grass and leaves, turning the sun’s energy into animals, which in turn, is food for carnivores and omnivores like us (organs, muscle meat, fats, blood, bone marrow, we can eat it all). Then when we die, our bodies return minerals to the soil, to grow more trees and grass. See how the circle of life is so beautiful and nothing is wasted?
Gorillas, cows and sheep all essentially eat a high-fat diet, using dietary fats as their principle source of energy. Humans are the same – much of our energy comes from fatty acids, broken down from dietary fats. Just like the cow breaks down fibre, and ferments it to produce VFAs, we just eat dietary fat and break that down into fatty acids.
Now go back to the low-fat craze. For 60 years, food companies and ‘diet experts’ told us to stop eating fats from animals, and they fed us more carbohydrates instead – sugar. We stopped eating a high-fat diet (yet almost all mammals on Earth eat a high-fat diet, as explained above) and switched to a ‘fast-burning, insulin-roller-coaster’ high-carb diet instead, built on processed grains and refined sugar. End result? Obesity and diabetes.
Humans are amazingly adaptable omnivores, and we can and do eat carbohydrates, and life would actually be pretty miserable without any carbs at all. But I don’t think we evolved to be eating very-high-carb diets, it’s just not how our digestive system works. Eat a lot of bread and pasta and listen to the farts! That’s carbohydrates fermenting in your intestines! I don’t believe we are really meant to thrive eating a ton of carbs, as we have not evolved to do all that fermenting! Mother Nature doesn’t provide a huge amount of naturally-available carbs for us to eat. In the Natural world, animal foods (muscle meat, organs, eggs, fish) don’t contain much carbohydrate. Only in plants do we find some carbs, and in the winter half of the year, in many parts of the world, those plants are not available.
In many vegetables, there is a lot of fibre, but not so much carbohydrate that we can digest. There are lots of carbs in tubers, yes, and in fruit too, but both of these foods were in far-less-abundant supply than today, thousands of years ago. We have bred them bigger, starchier, sweeter, and spread them around the world, bringing carbs to the human diet where little previously was available. More on this coming up later in this Myth busting mini series!
And you said cows aren’t vegans?
Right. Cows have very little feeling in their lips, if you have ever had a face-lick-wash from a cow you’ll know that their lips are big tough rubbery things and their tongues are…well, it’s like being licked by sandpaper! They are tough old things, with very few nerve ending in their noses and lips and tongue, so they can’t really feel much of what they are eating, and they eat pretty much anything that looks remotely like grass. This includes things down in the grass, such as spiders, stinging nettles, slugs, bugs, flies, bees, junk people throw into fields (sad truth), snails, ants, insects, flowers, plants, moss, bits of bird shit and dog poop, dead leaves and lots more. If it’s down there in the grass, cows invariably eat it, and that includes lots of insects, bugs, slugs and snails. Cows are not vegans, insects account for several percent of their total diet.
Sidebar – cow magnets
Sadly, humans discard a lot of metal waste in fields, from old nuts and bolts that fall off tractors, to discarded cigarette lighters, to the waste parts of Chinese lanterns that fall from the sky, to zippers off hikers clothing, keys, dropped coins, keyrings and more. Cows, being pretty dopey, eat this stuff. Down in the rumen it’s not too much of a problem, but if the parts make their way further into a cow’s digestive system they can cause real problems, piercing through the gut wall, where they can get into blood vessels and damage organs, so the cow has to have surgery to have the metal fragments removed.
So, to combat this, farmers now often feed cows (on purpose) with small ‘cow magnets’ which attract all the metal fragments in the rumen and keep them from progressing further into the digestive tract. If all the metal clumps together on a magnet, the clump becomes too big to pass further on, actually protecting the cow by staying in the rumen, where there is some chance the cow might be able to bring the clump up and get it out. Next time you let off Chinese lanterns ‘because they look pretty’ please think about where the waste ends up – and don’t throw litter into fields!
Some digestive action in humans is not unlike this digestive process going on inside cows and gorillas.
We humans can also make energy, from fatty acids, extracted from fibrous material, in the gut, using digestive enzymes.
While we have typically thought of dietary fibre as something we chew on, swallow then poop out, using fibre just to ‘keep the bowels moving’ there is in fact more to fibre than that. If (and the ‘if’ is the crucial bit) your gut flora is all in good order and functioning as it should and you have the right bacteria present, then there are bacteria and digestive enzymes in your gut that will break down fibre (fermentation, like the gorilla and the cow) to produce a short chain fatty acid called butyrate or butyric acid (the acid that makes human puke smell of that distinctive puke smell!)
Humans can then absorb some of this butyric acid through the gut wall, into the blood, and convert it to a form that can be used for energy, similar to glucose. This is not unlike how gorillas and cows ferment fibrous plant materials to make fatty acids which they use as their principle source of energy. But not everyone has the right balance of bacteria in their gut to make this happen, so for some people, most fibre does pass right on through.