It is an inevitable fact of life that we will all get ill from time to time. However, a healthy immune system means that the body has good defences and is less prone to catching illnesses, and is quicker to fight off the illness and its effects.

An unhealthy immune system can cause:

• Vulnerability to illnesses and diseases
• More prone to illness when moving through climate changes and time zones
• Longer recovery time
• Fatigue, lethargy
• Repeated infections
• Many colds and illnesses

The main cause of a weakened or unhealthy immune system is poor nutrition. The body is not getting enough nutrients to build up defences, and using all its energy to simply function.

Severe malnutrition may lead to immunodeficiency, which is when the immune system is hugely compromised or even entirely absent. Conversely, too much nutrition can lead to diabetes and obesity, but will not help the immune system after a certain point.

Things which weaken the immune system include:

• Too much alcohol
• Too much fat
• Too much sugar – sugar has an immune-suppressing effect

Foods which help the immune system include:

• Fruit and vegetables
• Certain herbs, such as Echinacea, ginseng, sage
• Drinking water
• Wholegrain foods
• Protein

However, there is not a list of simple methods that will work for everyone. A nutritionist can advise on what each individual needs, and what their body needs in order to build up its defences.

The body will require different levels of nutrition during different seasons. During the winter months there are far more cold and flu germs around, and the body is more vulnerable.

Knowing which nutrients the body needs can be confusing, and difficult to translate into actual food. Vitamins A, C and E are all important, and a nutritionist can tell you how to incorporate all of these into a healthy, balanced diet.

Sometimes supplements can help build up the immune system, but with such a wide selection available, from Echinacea to zinc to the ubiquitous pro-biotic yoghurts and drinks, it is hard to know which will be most beneficial. A nutritionist can tell you the reality behind the advert claims, and what the body really needs and when.