What is the immune system and what roles does it play in our health?
Think of your immune system as your body's personal army and repair team rolled into one. Every day we come into contact with thousands of viruses, bacteria, fungi and other potentially harmful microbes, yet most of the time we never become ill because our immune system is constantly working behind the scenes to protect us.
Its role extends far beyond fighting colds and flu. The immune system helps repair damaged tissues, removes worn-out and abnormal cells, supports wound healing and plays an important role in protecting us against disease.
One of its most important jobs is identifying and destroying potentially cancerous cells before they have the opportunity to develop further.
What factors can weaken immunity, and what signs might we experience if it is low?
Modern lifestyles place enormous pressure on the immune system. Chronic stress, poor sleep, excessive sugar consumption, insufficient exposures to the sun, lack of exercise, smoking, excessive alcohol intake, nutrient deficiencies (especially deficiency of antioxidants, vitamin D, C, B12, zinc, and selenium), and certain medications can all weaken our natural defences.
Sugar deserves special mention because diets high in refined sugar may promote inflammation, negatively affect gut health and significantly impair immune function over time. Since a large proportion of the immune system is associated with the gut, anything that disrupts the gut microbiome can have far-reaching effects on immune health.
Common signs that your immune system may not be functioning optimally include frequent colds and infections, slow recovery from illness, recurrent cold sores, poor wound healing, food sensitivities, and fatigue.
Health issues we can be at risk of due to prolonged low immunity?
Yes. Poor immune function can leave us more vulnerable to viral, bacterial and fungal infections, and may result in illnesses that occur more frequently or take longer to overcome.
However, immunity is not simply about being strong or weak. The immune system also needs to be properly balanced and regulated. Increasingly, researchers believe that chronic inflammation, poor gut health and immune dysregulation may contribute to the development of a number of long-term health problems.
Immune dysfunction has been linked to an increased risk of autoimmune conditions, where the immune system mistakenly attacks the body's own tissues.
A healthy immune system also plays an important role in identifying and removing abnormal cells, which is one reason why maintaining good immune health is considered important for long-term protection against various types of cancer.
Why are we more susceptible to infections in autumn, winter and early spring?
Several factors come together during the colder months. We spend more time indoors in close contact with other people, making it easier for viruses to spread. We are often exposed to less fresh air and less sunlight, and many people become less physically active.
Reduced sunlight exposure is particularly important because it can lead to lower vitamin D levels. Since vitamin D plays a key role in supporting normal immune function, this seasonal drop may partly explain why coughs, colds and other infections become more common during autumn and winter.
Cold weather and indoor heating can also dry out the nasal passages, weakening one of the body's first lines of defence against invading germs.
How can we strengthen our immune system through dietary and lifestyle choices?
One of the most important steps is eating a diet rich in colourful fruits and vegetables, which provide vitamins, minerals and antioxidants that help support healthy immune function. Adequate protein is equally important because immune cells are constantly being produced and renewed.
Reducing excessive sugar intake can also make a significant difference. Many experts consider sugar one of the biggest dietary obstacles to good immune health because of its effects on inflammation and gut balance.
Good sleep is essential. In fact, many researchers regard sleep as one of the most powerful natural immune enhancers available. Regular exercise, staying hydrated and learning to manage stress can also have profound effects on immune resilience.
Finally, don't overlook gut health. Around 70% of the immune system is associated with the gut, which is why a healthy diet rich in fibre, plant foods and fermented foods can be so beneficial.
