Although scientists have discovered several major cancer genes, the majority of cancers are caused by lifestyle factors and are preventable. The most well known causes are probably asbestos and smoking; each of which causes a different type of lung cancer. But whilst asbestos only seems to affect the lungs, smoking seems to increase the rate of most if not all cancers.
We can be sure that lifestyle and lifestyle related exposures cause all cancers because there are different rates of cancers in different countries. When people migrate and gradually adopt the foods and lifestyle of their new country, they also gradually assume the cancer profile (risks) of their new country.
There are two major general causes of cancer and both need to be present before cancer occurs. The first of these is known as inflammation and the second as immune suppression.
Inflammation: We can all recognise inflammation. It’s the red, usually swollen, sometimes hot feeling part of our body gets when it’s trying to help us recover from an infection or a cut or a bump of some type. Inflammation involves stimulating a lot of different cells to divide and wherever there are high rates of cell division then there is a high risk of the dividing cells becoming cancerous.
But it is good for us to have inflammatory responses isn’t it? Yes it is. Inflammation is an absolutely necessary part of our body’s self-healing system. But we need to keep it at a minimum; as the rescue system it is designed to be. We want to stop all unnecessary inflammation in order to prevent cancer.
So excess inflammation is very bad and we need to do all we can to reduce it. If we eat high fibre foods, we reduce intestinal inflammation and thus the risk of colon cancer. One of the dreadful side-effects of smoking is its effects on oral health: smokers have much high rates of gingivitis and gum disease than non-smokers and consequently, due to all this oral inflammation, they also have increased rates of oral cancer. If we don’t smoke and look after our dental health with good habits such as flossing, we reduce our risk of oral cancer. If we take care to avoid contracting sexually transmitted viruses – such as the papilloma virus – we reduce our risk of sexually related cancers. If we avoid sunburn, then we reduce the chance of skin cancer and so it goes on.
What is a little more complex is inflammation related to food components other than fibre. Glucose and sugar promote inflammation – cells just love these sugars and happily start to divide. So eating too much sweet food can cause inflammation. But some fatty acids are also inflammatory and this is one reason why we hear so much about having a relatively high intake of fish oil or fish that are rick in DHA and EPA, long-chain omega 3 fatty acids. The long-chain omega-6 fatty acid called arachidonic acid (AA), which is mostly found in red meat is inflammatory. However it is not all bad. If we totally eliminate AA we will do more harm than good and actually cause immune suppression, the subject of the second part of this ezine.