The colour of snot.

Andy and my self have had a virus all week. Our joints, muscles, head and any thing else you can think of hurt like hell. I also had, and still have a sore throat and ears. But it's the runny nose that has got me thinking, why when you have a heavy cold why is the snot always green? After over a box of tissues and half a toilet roll I decided to get to the bottom of it, or the nose of it in this case.
Here is what I have found out:

Contrary to what you might think, normal nose glop is vital for good health. It helps to protect your lungs and also helps keep your body moist ( it's always good to have a moist body, oooooooh matron). It contains proteins, carbohydrates, salt and some cells. The primary type of protein are the mucins, which have a sugar coating that enables them to absorb large quantities of water. Which gives mucus its consistency and wetting properties. These also contain antibodies that kick start the body’s defences against disease causing agents such as bacteria, viruses and fungi and antiseptic enzymes, such as lysozyme, that can directly kill bacteria. Isn't snot good stuff.

A stuffed up nose is caused when mucus gets trapped behind swollen nasal passages. They become swollen because of increased blood flow to that area,this occurs so that the goodie white blood cells can reach the point of infection. This is why decongestants can help your cold by shrinking the blood vessels and cutting down the blood flow, reducing the swelling. Except I can't use them. Ibuprofen upsets my stomach in a big way and sudafed gives me nightmares, that is if I can sleep after I have taken the dam stuff! But not all is lost, apparently if you have a runny nose then taking antihistamines can help by blocking the histamine-induced stimulation of mucus production.

white blood cells called neutrophils are amongst the first on the scene when a cold starts and arrive via the blood stream. Upon arrival they mount an attack. They attempt to engulf (swallow) the pathogen (a virus in the case of colds) and at the same time they produce antiseptic chemicals that wipe out other pathogens nearby. These chemicals are so potent that very little escape and are destroyed, committing suicide to fight the spread of infection. Generally, enzymes are responsible for the production of the antiseptic chemicals and it is these that give mucus the green colour. Enzymes often require ‘helpers’, called co-enzymes, to function properly and it is more specifically the co-enzyme iron that lends the green colour to mucus. Interestingly, it is similar to the iron containing enzymes in wasabi and that what makes it green too.

So, I finally I have my answer, why snot is green. It's the iron containing enzymes, and the same reason why wasabi is green, but thankfully snot is not as hot. I suppose if it was, you wouldn't have a cold, you would have a hot!
Most of my information came from Becky Poole from Bristol Uni . Well someone's got to do it. And here ends the lesson in The colour of snot.