Importance of the Immune System?

The importance of the immune system is underlined by the example of people who have been born with problems with their immune system (this can mean that it doesn't work at all, or that only parts of it work) – a condition called 'immunodeficiency'. Such individuals can become infected extremely easily, and the results can be fatal – this can mean living in a sterile environment, with only limited contact with people. Thankfully, many individuals can be helped with a bone marrow transplant that allows them to develop a working immune system (the bone marrow is the source for all of our immune cells) – however, this still depends on finding a suitable donor. There are other approaches being perfected however, such as replacing 'faulty' genes with working ones to correct the problem.

Infection with the virus causing HIV/AIDS infection is so dangerous because the infecting virus actually attacks immune cells, and so can destroy the immune system – giving people similar symptoms to those born without immune systems. This is what makes it such a devastating illness, and why it is so important to find a cure.

More positively, understanding how the immune system works has allowed us to develop amazing life saving operations to safely transplant organs such as kidneys, hearts, lungs and livers. Also, immune research into important diseases such as rheumatoid arthritis, type 1 diabetes, asthma/allergy and cancer, as well as infectious diseases such as HIV/AIDS and tuberculosis, is uncovering important knowledge about how these diseases develop, and new vaccines and therapies are becoming available as a result.

So, next time you feel a bit under the weather, bear in mind that your immune system is working hard to deal with the infection – and indeed is always working round the clock to keep you healthy. It's easy to take your immune system for granted because it's so good at what it does!

So what's good (and bad) for your immune system…

Although many things are said to "boost" the immune system, it isn't necessarily easy to prove this scientifically. However, there are some general points that can be made regarding 'immune health':

  • As the immune system needs a lot of the body's resources to function, any decline in essential nutrients is likely to have an effect. When nutrients are scarce, the body tends to favour the brain and certain other organs, and this can also affect the immune system. However, this tends to be in cases of severe malnutrition. It is always best to eat a balanced, and healthy, diet.
  • Most nutrients with antioxidant capacity (eg .Vitamin C, E, selenium, beta-carotene and other carotenoids) are associated with enhancing immune function, particularly in the elderly. In terms of dietary advice, however, care should be taken not to exceed upper levels of normal dietary intakes, as this may in fact have a detrimental effect. Citrus fruits are a good natural source of Vitamin C, for example.
  • Although Vitamin D used to be associated solely with developing strong bones, there is mounting evidence that it could play a role in the prevention or treatment of certain diseases through its effect on the immune system – including beneficial effects for respiratory health. Vitamin D is created naturally in the skin by the body, through the action of UV light. Recent concerns about the development of skin cancer through over exposure to sunlight are important to note. However, as long as exposure isn't excessive (and appropriate protection is applied) there are still benefits to going out in the sun!
  • Stress can affect immune function – one example being marathon runners and frequency of respiratory tract infections where there seems a 'window of opportunity' for infections immediately after a run, where the immune system is suppressed. Depressed individuals have also experience suppressed immunity, as the nervous system can directly interact with immune cells. So-called 'Neuroimmunology' is a new and emerging field of study. Exercise (provided not excessive) is a simple way to beat stress and improve mood.
  • Although extracts of the plant Echinacea have been claimed to improve immune function, and there are various models that may show some effect, there are, as yet, no proper clinical trials demonstrating any benefit on human immune function, in terms of health outcomes.

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Immunology explained website content authored by Daniel Price at the British Society for Immunology.