The term 'immune system' is commonly heard during the winter season. We all have one and it is essential for our survival. It is made up of several cells, organs and proteins working together to carry out bodily processes that fight off outside invaders, which include viruses, bacteria, toxins, moulds and foreign bodies that cause infection or disease. When the immune system comes into contact with a foreign organism, it triggers an immune response. Antibodies are released which in turn attach to antigens on the pathogens and kill them.

Over the winter period, we seem to fall sick more easily and as a pharmacist I often get asked: How can we improve the immune system? On the whole, your immune system does a remarkable job of defending you against disease, but it does fail at times: a germ invades your immune system successfully and makes you sick.

How can I boost my immune system?

Boosting your immunity is easier said than done and the whole process is much more complicated than we think. Our immune system is not one single organ; it's a complex system which needs to be well-balanced in order to function properly. Although you may already be aware of this, living a healthy lifestyle is the best way to strengthen an immune system.

How do I maintain a healthy immune system?

• Eat fresh fruits and vegetables daily
• Exercise regularly
• Sleep between 8 - 9 hours per night
• Drink alcohol in moderation
• Don't smoke
• Avoid stressful situations
• Keep your body well-hydrated
• Employ good hygiene practices - like washing your hands after using the bathroom and after coughing or sneezing

Does my diet have an impact on my immune system?

The immune system is often likened to an army. If you had a malnourished army, what's the probable outcome? It would be defeated very easily! In fact if you look at populations who live in poverty or those who are morbidly obese, you will notice that they are more likely to suffer from infectious diseases. There has not yet been a definite scientific link between our diet and our immune system. However, many diseases are often linked to deficiencies of certain nutrients, such as zinc, iron, selenium, Vitamin Bs, copper, folic acid, and Vitamin C, amongst others.

Will a daily multivitamin boost my immune system?

If you eat a varied diet which includes fruit, vegetables and a good protein source, multivitamins are not required. This is because you are probably already getting all the vitamins you need, and this is not one of the cases where more is better. Furthermore, your body absorbs and uses vitamins and nutrients better when they come from a dietary source. If you are a picky eater and not getting enough vitamins through your daily nutrition, then multivitamins can be a good way to ensure that your body is getting all it needs to function properly.

The vitamins we require to ensure a healthy immune system include: 

• Vitamin C - a lack of vitamin C can make you even more prone to falling sick. Foods rich in vitamin C include squash, oranges, grapefruits, tangerines, kiwi, strawberries, yellow bell peppers, spinach, kale, broccoli, cherries, thyme and parsley. Daily vitamin C intake is essential for good health because your body doesn't produce or store it.
• Vitamin B6 is vital in supporting reactions that occur within our immune system. Vitamin B6-rich foods include chicken, eggs, salmon, tuna, fresh ricotta, peas, chickpeas, avocado, spinach, bananas and carrots.

• Vitamin E is a powerful antioxidant that helps the body fight off infection. Foods rich in vitamin E include several nuts, sunflower seeds and spinach, salmon, avocado, red sweet peppers, and snails.
• Zinc keeps the immune system strong, helps heal wounds, and supports normal growth. Zinc can be found in beef, shellfish, legumes, nuts and seeds, eggs and potatoes.
• Selenium is only needed in small amounts but plays a major role as an antioxidant, and keeps our immune cells strong and able to fight off microbes. Best dietary sources include sardines, oysters, eggs, chicken breast, brazil nuts, tuna and mushrooms.

Does drinking water boost immunity?

Drinking water is very important for our health. Our blood is 90% water, which means it carries oxygen to our body and makes sure our body is working well. It also removes toxins from our body, thereby keeping a healthy balance within our internal system. So keeping hydrated is important even in winter, when we tend to reduce our water intake.

Does drinking alcohol have an effect on my immune system?

Researchers have long observed an association between excessive alcohol consumption and a weak immune system. A huge link between excessive drinking and pneumonia and chest infections has been established. So if you are trying to keep a healthy immune system in place drink alcohol in moderation.

Interested in reading more about the immune system? Check out how to boost your child's immune system, the correlation between stress and immunity and whether being cold weakens your defence mechanisms.