Cancer happens when genes, which contain coded information that tell our cells how to behave, get damaged by a carcinogen or by radiation. If genes are damaged, then cells start to behave wrongly.

Cancer cells divide more rapidly than normal cells and tend to stick together in lumps to form tumours. Malignant tumours can travel to other parts of the body and attack healthy cells, giving cancer its deadly nature.

We are exposed to carcinogens in our food, air and water all the time. For the most part, our immune systems recognise and destroy these cells before they have a chance to multiply. But sometimes the immune system is too weak to eliminate the offending cells and cancer takes hold.

Therefore, when looking at cancer prevention and survival, we need to adopt a two-pronged strategy.

The first is to minimise our exposure to carcinogens and the second is to boost the strength of our immune systems.

Eating a healthy diet is one way to take care of both these concerns. Healthy eating means including plenty of fresh fruits and vegetables in our diet: five or more servings a day and organic wherever possible.

Vegetables and fruits are packed with vitamins, minerals, fibre and antioxidants. Antioxidants like the vitamins A, C and E, beta-carotene and polyphenols have been shown to prevent damage by free radicals to cells and tissue in the body.

Avoid alcohol and instead drink plenty of pure water, eat more plant-based foods like grains and beans and limit the intake of fat, particularly saturated fat and fatty meats. Cancer diets, like the one suggested by experienced nutritionist Jan Dries, are often based solely on the consumption of raw fruit, raw vegetables, grains and seeds.

Limiting fat in the diet, together with a consistent exercise programme, can help maintain a normal body weight, which is important because obesity has been linked to cancer of the prostate, colon, rectum, uterus, ovaries and breast. Studies have also shown a direct link between exercise and a lower risk of breast cancer.

An even stronger relationship has been proven between cigarette smoking, including secondary smoking, and lung and other cancers. Tobacco smoke contains thousands of chemical agents, more than 60 of which are known to be carcinogenic.

The message is clear: all types of tobacco will put us on a course towards cancer. Therefore, rejecting tobacco is one of the most important health decisions we can make.

Stress is another big concern. When under stress our bodies produce hormones like corticosteroids that weaken the immune system. Cancer is accelerated in the presence of large amounts of corticosteroids and other stress-related hormones.

The way we respond to stress determines whether we are prone to cancer. Denial and poor or non-expression of feelings are high-risk characteristics. Emotional factors like depression, grief, repressed anger, helplessness and passivity or conformity lead to high cancer risk. The anti-cancer personality is positive, hopeful and expressive. This is how all of us probably started out but emotional traumas may have left us somewhere closer to the other extreme.

Therefore, a long-term but more fundamental approach to cancer prevention and survival is the willingness to work on our life issues so we can regain an open, balanced and optimistic perspective on life.

However, in times of great stress, for example the death of a loved one or the loss of a job, our immune systems could be weakened. At these times it may be helpful to seek some dietary help. There are several food products that are known to help boost immunity. Among these are bee pollen, echinacea, noni juice, apple cider vinegar and marine plants like kelp, spirulina, chlorophyll and seaweed.

Others like kombucha help the body detoxify, preparing the way for our natural defence mechanisms to re-establish themselves. But not all of these are suitable for everyone - our individual constitutions vary, so do your own research before jumping into any of them.

Skin cancer is one of the most common forms of cancer, so it pays to be sun smart. Staying in the shade, using sunscreen and not using indoor tanning beds or sunlamps are all common sense ways to prevent skin cancer.

Finally, be religious about regular screening and self-examination because early detection means treatment is more likely to be successful.