Why don't we drink pigs' milk and eat turkey eggs?
I am OMNIVOREMAN! I see it as my genetically programmed evolutionary duty to eat everything that I possibly can, from rotten walrus and palm weevils to insects and hamster food. The ability to eat pretty much anything has been vital to the survival of the human race. When certain foods like fruits became scarce, we were able to turn to others such as roots - by comparison the koala eats eucalyptus and little else, so when eucalyptus becomes scarce, the koala dies.
With the world population expected to reach nine billion by 2050, we desperately need new resource-efficient food sources to sustain the human race, so exploring and experimenting is still vital to our survival. So why are there some foods that must be available, but which we never seem to eat? Here are my top five:
7-8 million turkeys are eaten in the UK each Christmas Day, but their eggs are never sold in shops. The main reason is that turkeys lay less than chickens (around 110 turkey eggs per year as opposed to 300 chicken eggs) so they are relatively expensive and are invariably kept for breeding.
Of course you can eat grass, but you can’t get any great nutritional value from it. It contains a lot of cellulose, which is a carbohydrate (a sugar) but isn’t broken down very well in the human gut, so we have difficulty extracting energy from it. Cows and sheep have bacteria called symbiotic micro-organisms in their rumen which help to digest it, but to do so they need to eat, regurgitate and rechew their food almost constantly. However the very indigestibility of grass means that it can provide humans with useful dietary fibre (roughage). Good for the stool, if you know what I mean.
Although rhubarb is a great delicacy, it has a high concentration of a toxin called oxalate in its leaves, which can make you ill and potentially even kill you from cardiovascular collapse, gastrointestinal problems, respiratory difficulty, convulsions and coma. You’d need to eat a heck of a lot of rhubarb to get that far – probably around 5kg of leaves – but even a small amount can cause significant sickness.
We’re told to eat foods that are high in iron, so why don’t we simply chomp a hunk of metal every now and then? Well, in a way we do: elemental iron is sometimes added to cereals in the form of tiny iron filings (although the body absorbs it less efficiently than the iron fumarate usually found in supplements). But the body would have difficulty breaking down all the iron in a large mass such as a nail before it has travelled through the body, and its shape and hardness may also pose a grave danger to our delicate digestive system. More importantly, the body only needs the fractional amounts of iron that it extracts from foods (especially red meat, lentils, beans and fortified cereals) and too much iron can be highly dangerous. Iron poisoning in children (usually from eating ferrous sulphate dietary supplements) is a huge problem – it’s one of the leading toxicological causes of death in children under six.
Although pigs’ milk is high in fat (around 8.5% compared to cows milk at 3.9%) and is an excellent source of nutrients, sows are very difficult to milk. They have around 14 teats compared to a cow’s four, and they don’t take very kindly to having them touched by humans. They also get very agitated if you try to restrain them. Pigs also have a limited milk ejection time of around 15 seconds, whereas a cow’s can be up to 10 minutes. All in all, it’s a pig-shed load of trouble to milk a porker.
So over to you, which foods would you like to try that aren’t in the shops?