The immune system is the body’s ability to stay safe and healthy by protecting against disease and infection. It includes a complex network across our body of 5 litres of blood and lymph. A lymph is a clear and colourless liquid that passes throughout the tissues of the body. Together, these two fluids transport white blood cells throughout the body to monitor and destroy pathogens if identified.

1. White blood cells = Warrior

Like warriors fighting against the invader, white blood cells charge into battle at any sign of infection.

White blood cells can be classified by cell lineage either myeloid cells or lymphoid cells. Myeloid cells include neutrophils, eosinophils, mast cells, basophils, and monocytes. Monocytes and neutrophils can ingest the invader and process the info from the invader, helping lymphoid cells to identify what kind of pathogen it is.

Lymphoid cells include T cells, B cells and natural killer cells. T cell and natural killer cells kill the virus-infected cells and cancerous cells through chemicals. Unlike T cells, B cells produce antibodies to attack bacteria, viruses, and toxins that enter the body.

The immune system has memory to protect against the next infection by the same pathogen. If the same pathogen infects a second time, the body can quickly make copies of the corresponding antibody to destroy it.

2. Exercise keeps you healthy

We do not know how exactly exercise increases immunity, theoretically explanation was that the blood flow increases during exercise, it can circulate the white blood cells faster and detect illness earlier. Recent study shows aerobic exercise reduces inflammation markers in middle-aged and older adults [1]. So, stay active in your lifestyle and enjoy feeling healthier.

3. Eat right for strong immunity

High-glucose, high-fat and high-salt diets induce inflammation and promote disease development. In contrast, diets rich in fibre, vitamins and minerals such as vegetables, fruits, nuts, and seafood can promote a healthy immune response.

4. Stress can reduce immune health

During stress, a series of events release cortisol, adrenaline, and other stress hormones from the adrenal gland. These stress hormones suppress the effectiveness of the immune system by reducing lymphoid cells number [2]. It’s important to find a way to get rid of chronic stress. Some tips for reducing stress include exercise regularly, meditating or practising yoga, talk therapy, etc.

5. Sleep and immunity are closely tied

Consistent & high quality of sleep strengthens the immune response. When we sleep, our body produces T cells which protect us from infectious diseases such as COVID-19. Our body also produces cytokines that target infection and inflammation. Consistency is the most important factor in providing a quality night’s sleep. Maintaining a consistent sleep schedule promotes better sleep [3,4].


Click here for more information:

1. Zheng G, Qiu P, Xia R, Lin H, Ye B, Tao J, Chen L. Effect of Aerobic Exercise on Inflammatory Markers in Healthy Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Front Aging Neurosci (2019) 11:98. doi: 10.3389/fnagi.2019.00098