Our immune system is there to protect our bodies from microorganisms that can cause harm and illness, such as bacteria, fungi and viruses. But sometimes, your body’s immunity may not be working as efficiently as it could be. This can happen for a number of reasons, some of which we cover in this article, but we also look at some of the ways you can boost your immune system to decrease your risk of contracting an illness or infection.

What strengthens the immune system?

Maintaining a good weight

Being overweight can have all sorts of negative impacts on our body, from increased risk of diabetes and heart disease to extra pressure on joints^[1]. It’s thought that people who are overweight have a higher risk of contracting certain illnesses and infections because their immune system is not as able to fight these off. It’s still not clear whether being overweight is the cause of a weakened immune system or if it’s because of a poor diet that’s high in carbohydrates and fats.

By either losing weight or maintaining a healthy weight, you may be able to boost your immune system, and could find that you’re struck down with a cold less frequently^[2].

Sleep

Sleep is essential in order for our body to function as it should, fighting infection, repairing and healing and providing a much needed rest for your brain to process any new memories and information. But sleep is also essential for immunity, and lack of sleep has been shown to lead to increased sickness^[3].

Adults should aim to get at least seven hours of sleep at night. This will increase for teens (around eight to 10 hours) and younger children (up to 14 hours).

If you struggle to get this amount of sleep, you could try cutting out blue light for a couple of hours before bedtime. Lots of electronic devices, including mobile phones, televisions and even e-readers emit blue light that our brain mistakenly thinks is daylight. When this happens, you may find it difficult to settle at night and it could take you a long time to switch off. By removing these devices, you may be able to improve the quality and amount of sleep you get.

Hydration

Water is really important to keep us hydrated. When we’re dehydrated, our body can struggle to keep heart and kidney function normal, and can affect your mood as well as digestion. When these complications arise, the likelihood of contracting an illness increases. To boost your immune system, you should ensure that you’re drinking at least a few glasses of water each day.

Eating the right food

Food is absolutely crucial when it comes to staying healthy and free from illness^[2]. Healthy fats can assist by decreasing inflammation naturally, while whole plant foods, like seeds and nuts, contain lots of nutrients and antioxidants, which also decrease inflammation. Vitamin C is an essential vitamin that can ward off illnesses, particularly the common cold. When your immune system is working at its best, you’re less likely to get ill, meaning you can temporarily forgo the throat sprays and decongestants.

What foods boost the immune system?

So now that we know the impact food can have, which foods are the best for boosting your immune system?

Citrus fruits, like oranges, limes, lemons, clementines and grapefruit, all contain lots of vitamin C. This vitamin encourages your body to produce more white blood cells, and it’s thought that that’s why it’s so good at helping your body to fight infection^[4]. According to Healthline, red peppers contain almost three times as much vitamin C as the fruits we’ve listed above, so stick a handful of these on your salad for an extra boost.

Leafy greens are also one of the best things you can eat for your immune system. Vegetables such as broccoli, spinach and kale are packed with vitamins A, C and E as well as antioxidants. The key with these foods is to cook them as little as possible. When you boil them in a pan, for instance, lots of the nutrients escape from the food and into the water, which is drained later. Steaming is the best way to cook vegetables to retain those much-needed vitamins.

Finally, chicken may also help to boost your immune system, making the theory that chicken soup can cure any illness almost true. Chicken contains vitamin B6, which reduces inflammation and promotes the production of red blood cells, helping to fight off colds and other types of infections^[2].

Does exercise boost the immune system?

Light to moderate exercise can absolutely boost the immune system. Regular movement can help to reduce inflammation, which we’ve already stated can help your immune system, but it can also increase the production of immune cells, assisting in their regeneration^[2].

Moderate to light exercise includes anything from a brisk walk to jogging, cycling to swimming. You should aim to do around 30 minutes a day or at least 150 minutes per week.

What weakens the immune system?

While there are some things that can boost the immune system, there are also some things that can weaken it too. These include excessive alcohol consumption, smoking, sugary foods and stress. You can generally tell if your immune system needs a boost when you experience any of the following:

• You always have a cold
• You have digestive issues, such as constipation or diarrhoea
• Wounds, such as cuts, are slow to heal
• You experience frequent infections, such as multiple ear infections or pneumonia
• You feel tired all the time.

If any of the bullet points describe how you’re feeling, you should use our tips above to give your immune system a well-needed boost.

Resources:

[1] https://www.nhs.uk/conditions/obesity/

[2] https://www.leedsth.nhs.uk/assets/4ff9c0edea/Diet-and-lifestyle-to-support-immune-function-v2.pdf

[3] Besedovsky, L., Lange, T., & Haack, M. (2019). The sleep-immune crosstalk in health and disease. Physiological Reviews, 99(3), 1325–1380. https://journals.physiology.org/doi/full/10.1152/physrev.00010.2018

[4] https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-c/