Does what you eat make it easier to shake off colds and infections? Can it help keep bugs at bay? Your immune system is one of the busiest, most complex systems in your body, working around the clock to keep you well and what you eat helps it do its job. There’s no single food, supplement or trend that will “boost” it, but a varied, balanced diet, along with enough sleep and rest can help to support your immune system.
There are some nutrients that help:
Zinc
Although vitamin C is famous for helping to support a healthy immune system, zinc is one of the key nutrients you need. Studies show that one of the signs of zinc deficiency is frequent infections. Foods with the most zinc include meat, fish and shellfish. Adding foods like beef, salmon and mussels can help you reach targets for zinc. Nuts and seeds are also great sources, especially if you follow a plant-based diet. You can find zinc in pecan nuts, flaxseeds and sunflower seeds.
Vitamin C
Vitamin C really does help to support your immune system, but you probably do not need to take huge doses. Aim to get your vitamin C from food; that way you will pick up lots of other nutrients along the way. You will find vitamin C in all fruit and vegetables. Some of the foods with the highest levels of vitamin C include red peppers (126 mg), kiwis (71 mg) and oranges (37 mg). You need around 80 mg of vitamin C per day. Simply adding some fruit and or vegetables to every meal will make sure you are getting all the vitamin C you need.
Vitamin D
Vitamin D is often linked to healthy bones, as it helps your body to absorb calcium, but it is also an important part of a healthy immune system. We are supposed to get vitamin D from the sun, but anyone living in Ireland knows that sun is a rare and treasured thing. In winter, the sun that reaches Ireland is too weak for us to make vitamin D naturally, so we do need to get it from supplements and foods. The HSE recommends that we all take a vitamin D supplement from October to March every year.
Iron
Being low in iron can make you more prone to infections. You can be low in iron due to a poor diet, illness, heavy periods and conditions like coeliac disease and Crohn’s disease. Lots of people do not eat enough iron without realising it. Women need twice as much iron as men, which is why they are more likely to have low iron levels. You need two to three iron-rich foods every day. Red meat is a great source, but so are chicken legs, the brown meat, eggs, mussels, chickpeas and spinach. Nuts and seeds are also good sources of iron, including sunflower, pumpkin and sesame seeds. Breakfast cereals are often fortified with iron, and this can be an easy way to get iron into children’s diets. Check the labels. You should never take an iron supplement without a blood test first, too much iron is just as much of a problem as too little, particularly for the one in five Irish people who carry the gene for haemochromatosis.
Your gut and your immune system
Around 70% of your immune cells live in your gut, so looking after your gut microbiome is genuinely part of looking after your immunity. A varied diet rich in fibre, plant foods and fermented foods (like natural live yoghurt or kefir) is the simplest way to support both. SuperValu Natural Kefir or SuperValu Natural Yogurt are an easy daily add.
Can supplements help?
You’ll see plenty of supplements that claim to boost your immune system but the honest truth is you can’t out-supplement a poor diet. Food first is the best way to go when it comes to nutrition. For example if you eat a pepper for vitamin C and you also get fibre, polyphenols, water and a whole range of other nutrients. Take a vitamin C tablet and you just get vitamin C.
Life isn’t perfect though, and eating well every day isn’t always realistic. If you’re struggling, a supplement can help bridge the gap until things settle. A vitamin C and zinc supplement is a sensible option, or a general multivitamin if you want a bit of everything.
Diet is only one piece of the puzzle when it comes to immune health. Sleep, stress, movement and time outdoors all play their part, and getting these right is just as important as what’s on your plate.
Rest
Sleep is when your immune system does its repair and reset work, and when you’re not getting enough, it’s one of the first things to suffer. The aim is seven to eight hours a night where possible, ideally with the bulk of it before midnight, that’s where the most restorative sleep happens. This isn’t always realistic, especially with small children, shift work, or perimenopause sleep disruption. In those phases, the small things help most: getting outside in daylight first thing in the morning, putting the phone down 30 minutes before bed, or just protecting one quiet evening a week.
A short rest during the day also counts. You don’t need to nap, even 20 minutes with a cup of tea, away from your screen, can help.
Stress
Chronic stress wears down your immune system over time, and most of us are carrying more of it than we realise. Building in small moments of calm across the day can help. It could be a walk at lunchtime, ten minutes outside before pickup, time with friends, an evening that’s actually yours. It doesn’t need to be a meditation app or a yoga class. Whatever helps you switch off, even briefly, counts.
Do traditional remedies work?
Traditional remedies such as hot honey and lemon may not help cure your cold, but hot drinks can help loosen a blocked nose, and hydration can help you feel a little better. Lemon is a good source of vitamin C too. Hot tea, chamomile tea and hot chocolate can also be comforting when you are feeling unwell.