Boost your immune system
Our immune systems decline by about 2-3% a year from our 20s. Oh dear. Fortunately, a healthy diet and lifestyle can help! Read on for OnCore Nutrition’s top ten tips to optimise your immune system.
Drum roll please…
1. Spice up your life
Using herbs and spices in your cooking will boost your antioxidant intake to enhance immune function. Some herbs and spices may also assist with natural detoxification processes and others have antimicrobial properties.
- Try adding garlic, onion and ginger to your stir fries and slow cooking
- Warm up with curries full of turmeric, chilli, cayenne pepper, cumin
- Add cinnamon and cloves to your porridge, bircher or yoghurt
2. Get plenty of polyphenols
Polyphenols are found in plant-based foods and can help in numerous ways to enhance our immune systems. They have been shown to improve the immune response in our gut, activate our own immune pathways to keep us protected, and may be protective against cancer and various other chronic diseases. Eat. More. Plants. And drink them too!
- Eat plenty of fresh veggies and fruit. Just like your mamma always told you
- Add some berries, nuts and seeds to your brekky, yoghurt or smoothie
- Use herbs in cooking. Broaden your horizons with peppermint, oregano, sage, rosemary, thyme, basil, parsley and marjoram.
- Drink green or black tea, and red wine (you’re welcome!)…in moderation of course.
- Eat dark choc (you’re welcome again!)
- Cook with extra virgin olive oil as a preference
3. Sweet dreams
Seven to nine hours of sleep can boost the spread of T-cells which fight infection in the body. Some researchers found that just one average night sleep (of 4 hours) depleted the body’s natural killer cells by 70%.
Bluelights off, brush your teeth, hit the hay!
4. Remember that you’re sweet enough
Our immune systems need carbohydrates to function. But we need to be savvy about which ones we choose.
Eating or drinking high glycaemic index (GI) carbohydrates and simple sugars can reduce our immune response. After a dose of sugar, certain white blood cells called neutrophils may be far less aggressive in attacking bacteria. We don’t want that!
We’re best off getting our carbs in the form of complex, slow release (low GI) carbohydrates so we don’t have spikes in blood glucose levels. Choose whole grains, select breads and cereals as close to their whole food form as possible, include legumes and plenty of vegetables and fruit, and ease off the sweet drinks, cakes, biscuits and desserts.
5. Get your vitamins and minerals – but don’t jump for a pill.
Various micronutrients are essential for immunocompetence. There’s a lot. We’re talking vitamins A, C, D, E, B2, B6, B12, folic acid, iron, selenium and zinc.
Get them in naturally by including brightly coloured fruits and vegetables, such as berries, citrus fruits, kiwi fruit, apples, red grapes, kale, onions, spinach, sweet potatoes and carrots. Nuts, seeds, avocado, oily fish and shellfish are also loaded with nutrients that fire up our immune systems.
Supplements…worthwhile or expensive urine?
Many over-the-counter products claim to ‘boost’ your immune system, but there is little evidence to show that they do. If you have a poor diet, it may help to take a daily multivitamin, but the preference is to get all your nutrients from food, negating the need for supplements.
If you include a diet with lots of veg, fruit, wholegrains, legumes, nuts, seeds, oily fish or extra virgin olive oil – your immune system should have everything it needs to run optimally.
These supplements tend to fly off the shelves come winter time. We break down if they’re worth your time and money!
- Vitamin C – May reduce the duration of common colds and flu, but it’s very easy to get enough from our diet if you’re eating plenty o’ plants.
- Zinc – May reduce the duration and severity of a cold if started within 24 hours of cold symptoms.
- Andrographis – may reduce the duration and severity of cold and flu symptoms.
- Echinacea – studies are mixed and generally don’t support its use. Some studies suggest it may be helpful and others show little impact.
- Olive leaf extract (OLE) – Test tube studies suggest that OLE may have antimicrobial activities against some infective agents (including E. coli, Pseudomonas aeruginosa, Staph. aureus, Klebsiella pneumoniae and Candida albicans). Side effects seem to be rare so if you’re in the market even for a placebo, perhaps pick up some OLE tea!
- N-Acetyl Cysteine or NAC is the supplemental form of cysteine, a semi-essential amino acid. Some test-tube studies suggest it might be able to block the ability for some viruses (such influenza) to replicate. NAC has low bioavailability as an oral supplement, meaning that it’s not well absorbed. Get it naturally by including protein-rich foods (such as chicken, turkey, yogurt, cheese, eggs, seeds and legumes) and adequate amounts of folate, vitamin B6 and vitamin B12 (from beans, legumes, spinach, bananas, salmon and tuna).
- Vitamin E – there is no significant evidence that vitamin E supplements support the immune system and research suggests they may cause more harm than good.
Most supplements have dosage and interaction warnings. If you have any medical conditions or take any medications or supplements please check with your doctor, pharmacist or dietitian to ensure no interactions before considering any supplements.
6. Love your guts
Our intestines encounter more pathogens than any other part of the body. Given how many potential nasties enter our body via the gut, it is vital that our gut-associated lymphoid tissue (GALT) is primed to protect us.
The GALT represents almost 70% of our entire immune system and imbalances in our gut microbiota (the colony of bacteria that reside in our gut) may dysregulate immune responses.
Love your guts by:
- Munching on prebiotic fibres found in garlic, onions, leeks, asparagus, barley, oats, flaxseeds, edamame and the skins and seeds of fruits and veg.
- Lay off the heavily processed foods and artificial sweeteners
- Include kefir, kimchi, miso, tempeh and kombucha if you’re into them!
We all love potatoes. They make chips, mash, vodka. It’s like all the other veggies aren’t even trying. But did you know that cooked and cooled potato, pasta and rice become high in resistant starch – a type of carbohydrate that isn’t broken down and absorbed by our body. This means that what goes in goes straight out, and feeds the good bugs in our gut on their journey through! Potato salad anyone? The same goes for less ripe bananas. The closer they are to the green end of the spectrum, the higher they are in resistant starch. Feed your bugs!
7. Stress less
We realise this is easier said than done when the world is in crisis mode.
Our brain and immune system are buddies. They’re in constant communication. When we’re stressed, the brain produces more cortisol to prepare the body for emergency situations. In doing so it depresses our immune system.
- Take some time out to reset with relaxation exercises like yoga, meditation, mindful colouring
- Get into nature, walk the dog, play with puppies (the dream!)
- Paint your nails, take a bath, light a candle…whatever works for you!
8. Move it
Research tells us that we’re more likely to get colds if we don’t exercise. The impact that exercise has on sleep quality might also indirectly strengthen our immune systems. With certain viruses such as COVID-19 impacting our lungs and respiratory system, improving our lung function makes sense to help us stay strong and well.
- You all know the drill, 30 minutes a day, 5 days per week and make it something you enjoy (so you actually do it!)
9. Keep warm
You’ve all had someone wise tell you to ‘rug up’ to avoid a cold. Turns out they could be onto something…or at least partly. Cold viruses may be more infectious at temperatures lower than 37°C, which is the average core body temperature. Despite this, most health experts agree that the reason winter is “cold and flu season” is not that people are physically cold, but that they spend more time indoors in closer contact with other people who can pass on their germs.
10. Drink up!
Staying hydrated helps your body naturally eliminate toxins and other bacteria that might cause illness. See the box below for a guide on how much you should be aiming for. Focus on water, herbal tea and sparkling/soda water as your main fluids.
|Body weight (kg)
|Fluids needs per day
Studies have also shown that if you drink a glass of water before you start your meal you’ll eat 10% less…just saying…
Has anyone ever brought you chicken veggie soup when you’re unwell? Firstly, hang on to that special someone! Secondly, thank them for the triple whammy of immune goodness they’ve offered – protein and veggies for immune-boosting nutrients, liquid nourishment for hydration and the warmth for that body temperature.
Listen in to the OnCore Nutrition Two Peas in a Podcast for weekly evidence-based strategies to optimise your health!