The immune system is the body’s defence against germs and is essential for survival. It is made up of a network of cells, tissue and organs that work together to keep our bodies healthy. Our immune system protects us from germs to stop us from getting ill and most of the time, it does a good job. The immune system has three main functions:
1. Attacking pathogens (such as bacteria, viruses, parasites and fungi) and removing them from the body to prevent us from getting ill.
2. Recognising and netralising harmful substances from the environment.
3. Fighting against the body’s own cells that have changed due to an illness - such as cancerous cells.
The immune system is incredibly clever and recognises the cells that make up our bodies. When it comes across something it doesn’t recognise, it will try to get rid of it by attacking it. Our white blood cells play an important role in doing this. They work to seek out and destroy any germs which may cause the body harm. They are made and stored in various places around the body. These include the thymus, spleen and bone marrow. They also live in lymph nodes throughout the body. The white blood cells circulate through the body between organs and nodes seeking out germs and other foreign bodies. They travel around in your blood stream via lymphatic vessels and blood vessels.
How does the immune system work?
Every cell has its own tag which helps our body to know if the cell is familiar or not. When a foreign cell (antigen) enters the body it is quickly detected and several types of cells then work together to identify whether it is a threat to the body. If it is then antibodies (specialised proteins) are produced. They lock onto these antigens and then work with other cells to destroy them. If the body isn’t able to destroy the antigens straight away then the germs will multiply - causing you to feel ill. But, as your body destroys more of the germs you start to feel better.
Once produced these antibodies stay in a person’s body for life, meaning if those germs enter you body again you will be able to quickly identify them and destroy this. This is why for some diseases, such as chickenpox, you can’t normally get ill from it twice. This is also how immunisations work. They introduce the body to an antigen, without making the body sick, so that it will make antibodies and be protected from a future attack from that disease. This is known as immunity.
Antibodies also have a couple of other roles. They can neutralize toxins produced by different organisms and they also activate proteins which assist in killing bacteria and viruses.
What to eat to maintain your immunity?
Good nutrition is essential to a strong immune system, which offers protection from seasonal illness such as the flu and other health problems including arthritis, allergies and cancers. Help protect yourself against infection and boost your immunity by including these nutrients in your diet:
1. Protein is part of the body's defense mechanism. Eat a variety of protein foods including seafood, lean meat, poultry, eggs, beans and peas, soy products and unsalted nuts and seeds.
2. Vitamin A helps regulate the immune system and protects from infections by keeping skin and tissues in the mouth, stomach, intestines and respiratory system healthy. Get this immune-boosting vitamin from foods such as sweet potatoes, carrots, kale, spinach, red bell peppers, apricots and eggs.
3. Vitamin C protects you from infection by stimulating the formation of antibodies and boosting immunity. Include more of this healthy vitamin in your diet with citrus fruits such as oranges, grapefruit and tangerines, or red bell pepper, papaya, strawberries and tomato juice.
4. Vitamin E works as an antioxidant, neutralizes free radicals and may improve immune function. Include vitamin E in your diet with sunflower seeds, almonds, vegetable oils (such as sunflower or safflower oil), hazelnuts and peanut butter.
5. Zinc helps the immune system work properly and may help wounds heal. Zinc can be found in lean meat, poultry, seafood, milk, whole grain products, beans, seeds and nuts.