Boosting your immune system
Author: Nicole Saliba, Accredited Practising Dietitian Date Posted:24 March 2020
Keeping our bodies well nourished is essential for boosting our immune system and protecting us against illness. Here are our top tips for boosting your immune system and reducing your risk of getting sick!
Don’t let your vitamin D levels drop
When people think of vitamin D, they usually think about bone health. However, vitamin D plays numerous important roles in the body including building and maintaining strong bones, boosting the immune system and regulating muscle function. Vitamin D is critical for a range of common diseases and conditions including autoimmune (e.g. type one diabetes), cardiovascular (e.g. heart disease) and neurological disease (e.g. Dementia). A deficiency can lead to lethargy and fatigue, reduced wound healing and a decline in bone density.
Most of the vitamin D we get is from sunlight and there are minimal food sources including fatty fish, cheese and egg yolks. Vitamin D deficiency is common worldwide, particularly during the cooler months where the days are shorter and we spend more time indoors. In fact, 1 in 3 Australians have suboptimal levels of vitamin D. People who spend more time indoors, such as those working long daytime hours or the elderly are at highest risk. During June and July 2-3 hours per week of sun exposure is recommended for Aussies living in the bottom half of the country, while those in QLD, NT and the northern half of WA should get adequate vitamin D from just a few minutes per day. If your vitamin D levels are low (<75mmol) or your exposure to sunlight is limited including a vitamin D supplement is a great idea. Not sure if you need a supplement? Talk to your doctor or dietitian.
Load up on plants
Eating a plant-based diet rich in fruit, vegetables, nuts, seeds, legumes (.e.g chickpeas, lentils) and whole-grains may help give the immune system a boost. These plant foods provide the body with a whole host of immune-boosting nutrients such as vitamin C, Vitamin E, beta-carotene and zinc. Vitamin C and vitamin E are powerful antioxidants that help boost the body’s natural immune response. Vitamin C rich foods include capsicum, oranges, broccoli, strawberries, mango and lemons. Vitamin E rich foods include nuts, seeds (e.g. pumpkin and sesame seeds) and legumes.
Australian adults have a long way to go when it comes to meeting the recommended serves of fruit and veg! In 2014–15, 50% of adults ate sufficient serves of fruit and 7% of adults ate sufficient serves of vegetables.
Here are some tips for boosting your intake of plants:
- Start your day with a green smoothie: add 1 frozen banana, 1 cup of coconut water, 1 cup of baby spinach, ¼ avocado and ½ cup of frozen mango or pineapple
- Introduce 2-3 vegan meals per week such as a tofu stir-fry, chickpea curry, roast vegetable salad, vegetable burgers or home made baked beans on seeded bread
- Snack on veggies between meals such as carrots, celery, baby cucumbers and capsicum
- Include 1-2 cups of salad or vegetables with each main meal and aim for three different coloured fruits or vegetables per meal
- Keep some frozen veggies in the freezer for those times when you’re out of fresh vegetables
- Add tinned lentils or chickpeas to main sauces, curries and casseroles
- Snack on nuts between meals and add them as a garnish to meals
- Do a pantry swap out and swap refined products for whole-grain options. For example swap your corn flakes for porridge, muesli or weetbix. Swap white bread for good quality seeded bread. Swap rice cakes for ryvitas. Swap white rice for brown rice, quinoa or buckwheat.
- Use avocado as a spread instead of butter
Prioritise your sleep
Our bodies need adequate sleep in order to rest and recharge. A lack of good quality sleep not only compromises your immune system but can also increase your risk of obesity, heart disease and even Alzheimer's disease. We also know that people are less likely to make nutritious food choices when they have not slept well. Some studies have shown that people are more susceptible to catching a cold or flu when they have had inadequate sleep (<6hrs/night). Aim for 7hrs sleep if possible and avoid caffeine in the second half of the day and screens, stress, alcohol or high-intensity exercise before bed.
Boost your intake of zinc
Research shows that zinc is important for the immune system and wound healing. Good sources of zinc include oysters, lean red meat, pumpkin seeds, legumes (e.g. baked beans, chickpeas, beans, lentils), cashews, almonds, rolled oats and nutritional yeast.
Make friends with fat
Include oily fish such as salmon, tuna, sardines and trout 2-3 times per week as they contain a special type of fat called omega-3 fatty acids, which are essential for a healthy immune system as well as providing other immune boosting vitamins such as vitamin D. Cooking foods with extra-virgin olive oil will also help you absorb the fat-soluble vitamins in your meal including vitamins A, D, E and K. Including a handful of raw unsalted nuts per day is also a great way to get some extra plant-protein, zinc and vitamin E.
Look after your gut!
Most of your immune system resides in your gut so it makes sense that looking after it is a good idea to boost your immune system. Here are our top tips for boosting your gut health
- Aim for 30g of fibre per day
- Aim for two serves of fruit and five serves of vegetables per day and aim for a variety of different colours
- Swap refined cereal products for whole-grains such as porridge, rolled oats, muesli, brown rice, quinoa, buckwheat, wholemeal pasta, good quality seeded bread and whole-grain crackers,
- Reduce your intake of artificial sweeteners e.g. diet soft-drinks, sugar-free lollies
- Cut back on your alcohol intake
- Include fermented foods such as yoghurt, kefir, sauerkraut, kimchi, tempeh and kombucha
- Reduce your intake of ultra-processed foods
For more information or for a remote consultation with an Accredited Practicing Dietitian, please contact Nicole at Eatsense.