The immune system functions as the vigilant guardian of our health, comprising a sophisticated network of cells, tissues, and organs working tirelessly to protect the body against harmful invaders. The immune system plays a pivotal role plays in preventing illness and promoting optimal health. A robust immune system not only safeguards against infectious diseases but also contributes to swifter recovery and the overall resilience of the body.

In a world brimming with environmental stressors, pollutants, and the constant threat of emerging diseases, fortifying your immune system becomes a proactive measure for a healthier life. This blog provides practical tips, evidenced by research, on how you can boost your immune system through exercise, diet, physiological stress and sleep. So you can help your body defend against disease-causing microorganisms.

What is the immune system?

The body is constantly challenged with environmental bacteria and viruses that can infect us. We have complex ways to deal with these infections, which is divided into the innate and the adaptive immune response (1). This is known as the immune system.

Your immune system is fundamental for defending your body against disease-causing organisms.

How can the food I eat boost my immune system?

Vitamin C

Vitamin C is known for its anti-inflammatory properties. Within the body, it strengthens the immune response against viruses and bacteria. Vitamin C is commonly known to play a key role in preventing common colds. Supplementing Vitamin C have also been shown to reduce the severity of common colds in children and adults (1)

Vitamin C can be found in oranges, citrus fruits, strawberries, tomatoes, broccoli, sprouts, kale and blackcurrants (2).

Vitamin D

Vitamin D can be made in the body through exposure to sunlight and also enter the body through the food we intake. Vitamin D has anti-inflammatory properties within the body and plays a vital role in immune function. Having sufficient vitamin D helps to prevent autoimmunity within the body (1).

The main way to meet your optimal vitamin D requirement is through sun exposure which is enough to allow the body to naturally increase synthesise vitamin D within the body. The National Institute of Health (NICE) recommends unprotected sun exposure of 5-30 minutes between 10am – 3pm two to three times a week.   

The main natural food sources of vitamin D are fish oil, cod fish liver, egg yolk, mushrooms, salmon and yogurt.

Folic Acid

Also known as Vitamin B9. Folic acid has protective properties against viruses (1).

Food sources rich in folic acid are peanuts, sunflower seeds, asparagus and lettuce.

Magnesium

Magnesium is known to provide essential support to the normal functioning of the body’s immune system by affecting the cells in the innate and adaptive immune systems (1).

The main sources of magnesium that you can get through your diet are bananas, nuts, black beans, wholegrains, flaxseed, green vegetables and pumpkin seeds.

Zinc

Zinc is also a key player in the normal function of the immune system (1). Your body needs zinc to help fight off infections and to promote skin health and effective wound healing.

Zinc is found in meat, fish and seafood. Oysters contain more zinc than in any other food!

What’s the best way to make sure I eat the right food to support my immune system?

• Eat the rainbow – the more naturally diverse colour the foods you eat, the better as each colour generally represents a different essential nutrient
• Include superfoods such as dark leafy greens, berries, eggs, green tea, legumes, nuts and seeds, kefir, garlic and olive oil
• Fuel your microbiome by eating probiotic foods such as kefir, yogurt and fermented vegetables and prebiotic foods such as onions, leeks, asparagus and bananas

Does exercise affect my immune system?

Exercise can help with optimal immune response by regulating the number of white blood cells and inflammatory molecules, which both play key roles in normal immune responses.

Exercise also plays a role in reducing the risk of chronic metabolic and cardiorespiratory diseases, which can be partly down to the anti-inflammatory effects of exercise. It can also help to manage blood pressure and maintain healthy body weight.

Regular exercise of around 45 minutes per day is beneficial for the immune system. Just like a healthy diet, exercise is a key player in good health and a healthy immune system.

Stress is also linked with immune function

There is much ongoing research to understand the connection between the mind and body within the field of medicine.

Chronic stress is actually linked with a supressed immune response (3). Stress raises cortisol levels, which can weaken your immune system if raised too high for too long. It can also trigger inflammatory immune responses, which can make you more at risk of viruses and infections.

How can I manage my stress levels?

• Try relaxation techniques such as breathing
• Get out for regular walks throughout the day
• Unwind before bed
• Practice meditation

Does sleep play a role in my immune system?

Sleep is fundamental to a healthy immune system. Did you know that one night of 4 hours sleep can acturally drop your natural killer cell count by 30% (4). Not sleeping for long enough at night can reduce the amount of Killer cells. Killer cells play a critical role in a healthy immune response, and they are essentially the first point of call for identifying unwanted elements and eliminating them.

Getting a good night’s sleep of 7-9 hours is therefore incredibly important to make sure your immune system is functioning at its best.

What can I do to improve my sleep?

• Have good sleep hygiene
• Wind down before bed, have a hot shower or bath
• Reduce alcohol consumption
• Avoid screens before bed
• Try camomile tea before bed