What Is The Immune System?

The immune system is a vast network of cells and tissues that protects the body from infections.The immune system can distinguish our tissue from foreign tissue, such as viruses, bacteria, parasites and toxins. Dead and faulty cells are also recognised and cleared away by the immune system.

The immune system is spread throughout the body and involves many types of cells, organs, proteins, and tissues. The skin, the eye’s cornea, and the mucous membrane that lines the respiratory, gastrointestinal, and genitourinary tracts act as physical barriers against harmful microorganisms and foreign cells. When a foreign organism is recognised, the white blood cells in these tissues (phagocytes – a type of white blood cell) are activated to surround and cover the invader.

Immune System Function

For the immune system to function optimally, it requires all our cells, organs, proteins and tissues to work together harmoniously.

In a dysfunctional immune system, the immune system may fail to recognise an infection and not elicit an appropriate response to get rid of the foreign organism. At the other end of the spectrum, in autoimmune conditions, the immune system is unable to differentiate a foreign organism from our own tissue and  mounts an inappropriate inflammatory response to our own tissue.

The most common indications of suboptimal immune function are an increased tendency to experience colds, flu, sore throats, sinusitis and other minor respiratory, gastrointestinal or skin infections, and needing more time than usual to recover from them. You may also feel generally unwell or lethargic, and may experience enlargement and/or tenderness of the lymph nodes in your neck, underarms or groin.

Factors Affecting The Immune System

Reduced immune system function is sometimes a symptom of underlying medical problems, but is more commonly a consequence of poor diet and lifestyle habits.

Nutrition

A whole food diet, with a good balance of macronutrients of protein, carbohydrates, fat and fiber and essential for a well-functioning immune system

Minerals and vitamins such as vitamin C, zinc, magnesium, Vitamin D and Vitamin Bs  are essential for the production and activation of immune cells for a healthy functioning immune system.

Antioxidants, such as selenium, gluthathione, vitamin E, vitamin A, alpha-lipoic acid, coQ10 also improve immune function and exhibit a protective role in infections caused by bacteria, viruses or parasites.

Make sure you are eating a good quality well balanced diet regularly. During situations where there is an increase in infections around you or when you are undergoing more stress and poor sleep, supplementing with the minerals, vitamins and antioxidants listed above can be helpful.

舒缓压力

Intense or ongoing stress impeded immune system function. The stress hormone, corticosteroid, can suppress the effectiveness of the immune system, by lowering the number of circulating lymphocytes – thus increasing your risk of infections.

Take steps to manage your stress levels. Useful options that can help with stress levels are exercise, meditation and therapy.

改善睡眠

Lack of sleep has also been shown to increase your susceptibility to cold viruses.  Studies show that people who don’t get quality sleep or enough sleep are more likely to get sick after being exposed to a virus, such as a common cold virus. Lack of sleep can also affect how fast you recover if you do get sick. During sleep, your immune system releases proteins called cytokines, some of which help promote sleep. Certain cytokines need to increase when you have an infection or inflammation, or when you’re under stress. Sleep deprivation may decrease production of these protective cytokines. In addition, infection-fighting antibodies and cells are reduced during periods when you don’t get enough sleep.

Some ways increase the quality of your sleep can be through limiting your consumption of energy drinks, such as caffeine, after lunch. Lavender, Chamomile, Magnolia Bark, Valerian Root and Blue Skullcap are some of the herbal remedies and natural sleep aid that can help increase sleep quality. Learning to manage stress and anxiety levels through exercise and meditation can also help with sleep.

Age

Our immune systems are not fully developed at birth, and as a result, children are more susceptible to colds, flu and gastrointestinal infections than adults are. At the other end of the lifespan, reduced immune function and increased vulnerability to infection is a common feature of old age, especially among people whose diets are poor. Some research have suggested that in many cases, this phenomenon may be at least partially due to low levels of zinc.

Cigarette and alcohol consumption

Smoking cigarettes or recreational drugs may make it easier for infections to occur by inhibiting the functioning of the cilia. These tiny hair-like projections line the respiratory tract, where their roles include helping to prevent infectious organisms from entering the body and facilitating the expulsion of mucus and phlegm from the airways so that they don’t become a fertile breeding ground for bacteria.

Similarly, excessive consumption of alcohol may deplete immune system function over time by interfering with the balance of the various types of immune cells in the body and their ability to communicate with each other. Among other consequences, this may increase susceptibility to some infectious diseases, including some respiratory infections.

Reducing or eliminating cigarette smoking and alcohol in our diet will help with improving our immunity.

Dr Deborah Wong

Deborah is senior medical advisor at Life Clinic. Dr Deborah Wong obtained her MBBS from the National University of Singapore and post graduate training in Family Medicine with the College of Family Physicians Singapore. She is currently pursuing her Fellowship with the Australasian College of Nutritional and Environment Medicine.

She has a special interest in preventive health, women’s health and sports medicine. She has also undergone training and attained various certifications in exercise medicine and Clinical Orthopedic Manual Therapy.

She believes that healthcare should be holistic, and treatment should involve mind, body and soul. With a passion for movement, she is also co-owner at Breathe Pilates and enjoys olympic weightlifting in her spare time.