Your immune system is powerful and incredibly complex. It does many jobs that are vital to your survival, including protecting against invading microbes and helping you heal after an injury.
But the immune system is a finely tuned operation: if it overreacts, this can cause unnecessary inflammation and lead to damage. On the other hand, if it doesn’t respond strongly enough, microbes are more likely to settle down and make you sick.
This is why ‘boosting’ your immune system doesn’t make sense – an overactive immune system is just as bad as an underactive one.
What you need instead is balance.
In this article, we explain how to support your immune health through dietary choices and other simple lifestyle changes.
Foods and nutrients to support immune health
Several key nutrients are involved in the smooth running of your immune system, including:
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vitamins: particularly A, B1, B2, B3, B12, C and D
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minerals: including zinc and selenium
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amino acids: such as arginine and tryptophan
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fatty acids: like omega-3s and omega-6s
Now, if you want to look after your immune system, you might feel an urge to go out and buy supplements that contain these nutrients. But it’s more nuanced than that.
When it comes to nutrients, more isn’t always better – your body needs just the right amounts. Thankfully, it’s excellent at maintaining the correct balance.
Also, taking high doses of vitamins, especially the fat-soluble vitamins A, D, E, and K, can be harmful. There’s no simple way for your body to get rid of them, so levels of these vitamins can build up beyond what’s good for you.
Remember that a vitamin and mineral supplement contains a concentrated dose, so it's possible to take more than you need.
When you can, it’s best to get these immune-healthy nutrients from what you eat. Anyone who keeps up a well-balanced diet will have adequate levels.
While supplements can be tempting, foods offer far more than just vitamins and minerals. They can be full of fibre, protein, healthy fats and plant compounds, such as polyphenols.
Overall, foods are far more complex than supplements, and nutritionally, you're getting more bang for your buck with whole foods.
The one exception involves ‘the sunshine vitamin,’ vitamin D, which is produced in your skin in response to sunlight.
The NHS recommends that adults consider taking a vitamin D supplement during the winter months. And anyone at risk of not getting enough vitamin D should take a supplement year-round.
Which specific foods can support your immune system?
If you Google this question, you’ll find an endless list of foods that allegedly support immune health. In reality, it’s about your whole dietary pattern, and diversity is key.
So rather than focusing on ‘superfoods’ (which is a marketing term, not a scientific one) try to follow a well-balanced diet that includes:
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fruits
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vegetables
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whole grains
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nuts
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seeds
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legumes
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pulses
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oily fish
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dairy
These foods support the health of your whole body, not just your immune system. They also help look after your gut microbiome, which is an important factor in immunity. We’ll dive into the details below.
Support your gut, support your immune health
Your gut contains trillions of microbes, collectively called your gut microbiome.
The latest science shows that these organisms support the health of your heart, your brain and many other organs and functions in your body.
Your gut microbiome is closely linked to your immune system – around 70–80% of your immune cells live in your gut.
Experts believe that gut bacteria help train your immune system, teaching it to fight off ‘bad’ bacteria but leave ‘good’ bacteria alone.
A healthy gut microbiome also helps keep inflammation in check.
So, if you want to follow a gut-healthy diet, the plant foods listed above are all rich in fibre – the main nutrient that gut microbes need to thrive.
Fermented foods and probiotics are also great additions to your diet. They contain bacteria that support your community of gut microbes.
On the other hand, certain foods and drinks won’t support your gut microbiome, so try to limit your intake of:
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high-fat foods, such as fried foods, takeaways, pastries and pies
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high-sugar foods, such as sweets and chocolate
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high-salt foods, such as crisps, bacon and sausages
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alcohol
Food additives are another factor to consider. While we don’t have definitive evidence of their health impact yet, researchers are investigating the potentially negative effects of additives such as artificial sweeteners and emulsifiers on the gut microbiome.
Lifestyle factors that can support your health
Beyond tweaking your diet, you can make other science-backed lifestyle changes to support your immune health.
Stress and immune health
Research shows that long-term (chronic) stress can affect how well your immune system works.
That’s because chronic stress can suppress or disrupt immune function through the action of stress hormones, such as cortisol.
This can drive inflammation, lower immune resilience, and increase the risk of illness and infection.
It’s impossible to avoid all stress, and life might be a bit boring if you did. But learning how to manage your stress successfully can support your immune system’s functioning.
If you feel like stress is having a long-term impact, here are some ideas:
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Keep physically active – we’ll talk more about this just below.
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Connect with friends and family.
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Take some time to focus on doing things you love.
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Help out other people, maybe by volunteering.
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Practice mindfulness or meditation.
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Join a local club to connect with others.
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Try yoga or breathing exercises.
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Go for a walk in nature.
If stress is significantly affecting your life, and nothing seems to help, speak with your doctor, who can provide further advice. Apps like Headspace and Calm also have resources that may be helpful.
Support immunity with exercise
Exercise is vital for maintaining good health. It also helps support your immune system, reducing your risk of infections and making vaccines more effective.
But to get the benefits, you need to do it regularly. The World Health Organization (WHO) recommends:
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at least 150–300 minutes of moderate-intensity aerobic activity per week, or
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at least 75–150 minutes of vigorous aerobic activity, or
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an equivalent mix of moderate and vigorous activity throughout the week
The key to regular exercise is to find something you love. Whether it’s walking, running, lifting weights, calisthenics, parkour, skateboarding or gardening, it all counts.
In the long run, keeping active will support your entire body, including your immune system.
What to avoid
No health article would be complete if it didn’t advise you to reduce your intake of alcohol, if you drink, and quit tobacco, if you smoke or use any other tobacco products.
Research has shown that alcohol interferes with immune function in a number of ways, including upsetting the balance of the gut microbiome and disrupting immune cells in your airways.
Nicotine's relationship with your immune system is complex. In some circumstances, it can reduce inflammation, and in others, increase it. Either way, nicotine upsets the immune system’s finely tuned balance.
You might also benefit from reducing your caffeine intake. Getting adequate, good-quality sleep is another important factor in immune health.
Everyone responds differently to caffeine, but if it interferes with your sleep, consider switching to decaffeinated drinks, or not having any caffeine after 2 p.m.
Other ways to support immune health
Other factors that might benefit your immune system include:
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prioritising sleep
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maintaining a healthy weight
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washing your hands regularly
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staying up to date with your vaccinations
It’s also important to cook foods adequately to help prevent infections.
What about supplements for immune health?
The immune system is highly complex. And as we’ve mentioned, it’s a balancing act.
Vitamin and mineral supplements definitely have their place, particularly if you have a deficiency in certain nutrients that play key roles in immune function.
With that said, most people can meet all their nutritional requirements through a healthy, balanced diet.
In general, it’s best to support your immune system with the lifestyle changes we’ve outlined above, unless your doctor tells you otherwise.
FAQs
Here are some answers to frequently asked questions about the immune system.
What are 5 signs of a weak immune system?
Some signs that you might have a compromised immune system include: regular infections, slow wound healing, gut symptoms, unexplained fatigue and long recoveries from minor illnesses.
How can I strengthen my immune system?
The best ways to support your immune system involve having a balanced, diverse diet that includes all the food groups, sleeping well, managing your stress levels, avoiding nicotine and alcohol, and staying physically active.
Which vitamins are good for the immune system?
The most important vitamins for immune function are vitamins A, B1, B2, B3, B12, C and D.
Rather than taking supplements, it’s best to get these vitamins from foods. If you have a balanced diet, you’ll be getting the right amounts of these and other nutrients.
It’s important to remember that getting more of these vitamins won’t necessarily benefit your immune system. In fact, large doses of some vitamins can be harmful.
Summary
Your immune system helps keep you healthy, so it’s a great idea to support it. The best, science-backed recommendations are: to have a well-rounded, healthy diet, stay physically active, minimise stress and practice ways to manage it effectively.
Avoiding alcohol and tobacco, getting enough sleep and limiting your exposure to pathogens will also help.
To learn more about other health topics, visit Symprove’s Gut Hub.
Sources
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Alcohol and the immune system. Alcohol Research. (2015). Link.
Artificial sweeteners: A double-edged sword for gut microbiome. Diseases. (2025). Link.
Effects of regular physical activity on the immune system, vaccination and risk of community-acquired infectious disease in the general population: Systematic review and meta-analysis. Sports Medicine. (2021). Link.
Food additive emulsifiers and their impact on gut microbiome, permeability, and inflammation: Mechanistic insights in inflammatory bowel disease. Journal of Crohn's and Colitis. (2021). Link.
Gut microbiota modulation on intestinal mucosal adaptive immunity. Journal of Immunology Research. (2019). Link.
Immunology of stress: A review article. Journal of Clinical Medicine. (2024). Link.
Nicotine in inflammatory diseases: Anti-inflammatory and pro-inflammatory effects. Frontiers in Immunology. (2022). Link.
Stress-induced enhancement of immune function. Stress: Immunology and Inflammation. (2024). Link.
The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies. Nutrients. (2021). Link.
The relationship between nutrition and the immune system. Frontiers in Nutrition. (2022). Link.
The role of gut microbiota biomodulators on mucosal immunity and intestinal inflammation. Cells. (2020). Link.
Vitamin D. (2023). Link.
WHO guidelines on physical activity and sedentary behaviour. (2020). Link.
