We all know that smoking can lead to cancer. But why?
We grow up surrounded by advertisements and the like telling us that smoking is bad and causes cancer. We know that by taking up the habit we are essentially increasing our risk of dying early from the big C or another horrific disease. But do we actually get told why smoking is so terrible? This post will hopefully shed some light onto just why smoking is one of the primary causes of many forms of cancer.
Cigarettes contain a range of substances which we really shouldn’t inhale. Nicotine is addictive, and is why it is so hard to quit. But the main reason smoking leads to cancer is due to the carcinogens found within the tar of the cigarette.
Your DNA is important. It is important that your DNA is in good condition so that it can continue to code for healthy genes which you need in order to live. However, DNA can undergo mutations which lead to it not being able to work properly, which can lead to cancer.
Think of the DNA as a zip. When it is together it is holding everything in place and doing its job as it should. But when it needs to copy it separates. This is a normally efficient process, much like undoing a zip is. Quick and easy and fulfils its role. However, when mutations occur, this is more difficult. Think of one of the teeth being missing from the zip. It is harder to open, though you might manage it with a bit of wiggling. That is like the mutations which happen to your DNA which are not serious (in fact, the DNA is usually repaired quite easily when this happens). However, now imagine that several of the teeth are missing. It is now much harder to open the zip, as it will keep getting stuck, or may just jam entirely. This is similar to having multiple mutations. When the DNA gets too many mutations, it cannot be easily repaired.
When this happens, the DNA replication is not correct. This is especially dangerous when the mutations are on specific genes which are involved in the control of cell division, as outlined in my summary of them. When this happens, cells divide rapidly and uncontrollably, which is how tumours form. These are potentially cancerous.
We come into contact with potential substances which could mutate our DNA on a daily basis, and yet many people are absolutely fine. Smoking, however, increases the risk because you are directly inhaling large quantities of the very substances which can cause cancer (amongst other things) inside your body. It is why second hand smoking is also such a risk – people who work in busy city centres or who live with smokers are more likely to also develop these mutations as a result of frequent contact with the smoke, even if they do not have the cigarettes themselves.
Obviously cancer is complex, and there are many other underlying factors including genetics, diet and lifestyle. But smoking is by far and away one of the most harmful habits you can take up. As much as you might think you want the cigarette, your DNA could really do without you smoking it.
For help in quitting smoking, take a look here.