A Nutritionist Writes | Can You Boost Your Immunity Through Food?

Unfortunately, no specific food or supplement will protect you from germs or catching a virus. Good hygiene practices remain the best means of avoiding infection.

However, if we do catch a virus, our immune system is responsible for fighting it. Research suggests that improving nutrition can help support optimal immune function, which is critical to helping us stay healthy and feel our best.

Essential nutrients & where to find them

The good news is that following common-sense dietary advice is enough to keep your immune system in good shape; no expensive supplements or difficult-to-source superfoods are required.

Vitamins (especially A, C, and D and minerals such as zinc) have a vital role in the functioning of our immune system, but they are also practically unavoidable components of our diets, as they are present in large quantities in fruits and vegetables and other whole foods. Barely anyone is deficient in Vitamin C, so taking a mega dose won’t super-power your immune system (it will just come out in your urine and may upset your stomach in the process).

Simply focusing on eating a variety of foods within each of the main food groups will boost your intake of key vitamins and minerals:

• Vitamin A: Oily fish, egg yolks, cheese, tofu, nuts, seeds, beans, pules & wholegrains
• B Vitamins: Meat, fish, dairy, nuts, fortified soya milk, breads & green leafy vegetables.
• Vitamin C: Oranges, lemons, limes, berries, kiwi fruit, broccoli, tomatoes & peppers
• Vitamin E: Nuts, green leafy vegetables & vegetable oils
• Iron: Meat and fish, beans, pulses, legumes, wholegrains & dried fruits
• Zinc: Oysters and other seafood, meat, chicken, grains, beans & nuts

Therefore, you’re likely to get the amount you need if you eat a healthy diet. Very limited evidence suggests that supplemental vitamins or minerals will help you fight off infections.

The exception is Vitamin D. Although it is found naturally in a few foods (see above), it’s difficult to get the recommended amount from food alone.

Our primary source of vitamin D is from the action of sunlight on our skin. To ensure a healthy vitamin D status, adults and children over the age of one should consider taking a daily supplement containing 10 micrograms of Vitamin D if they struggle to get adequate sun exposure year-round. Most people need just a few minutes outdoors most days.

“You don’t want to ‘boost’ your immune system – if we did, our bodies would overreact to harmless substances, causing a needless reaction! So be wary of ‘immune boosting’ products. Supporting a healthy immune system with a good diet is more than enough to keep you well.”

Support your Good Bacteria

Every time we eat, our gut bacteria break down our food and use it to grow.  Healthy gut bacteria produce beneficial compounds that help you function optimally and are beneficial for your immune system’s functions.

If you have an imbalance of bacteria in your gut (caused by stress, a highly processed diet, or repeated bouts of antibiotics, amongst other things), they can produce compounds that lead to an inflammatory response that isn’t supportive for your overall health and immunity. That’s why eating a diet that encourages a healthy balance of bacteria is so important. A gut containing plenty of healthy bacteria leaves the immune system with plenty of time to handle its many complex everyday functions.

4 ways to keep your gut bacteria happy and support your immunity

1. Eat fermented foods such as kimchi, sauerkraut, kombucha, yoghurt and kefir. These are important as they are sources of healthy bacteria.
2. Get enough prebiotic fibre. Prebiotic fibre foods are essential because they feed those healthy bacteria and encourage them to grow. Gut-friendly prebiotic fibers include fruit and vegetables, especially Jerusalem artichokes, asparagus, onions and garlic, tomatoes, whole grains, and legumes.
3. Choose vegetables in a range of different colours. These contain essential antioxidants called polyphenols that activate pathways to help reduce your body’s inflammatory response. They are also rich in insoluble fibre that your body can’t ordinarily break down. This is not only good for feeding gut bacteria, it helps material move through the gut.
4. Exercise. That daily run or walk is essential to the health of your gut and the rest of your physical and mental wellbeing. So, you must do something mildly strenuous every day. Exercise gets your blood circulating, and the mechanical action of bouncing up and down helps move things through the gut too.