nutrition & immunity

Photo by Bruna Branco on Unsplash

Article by Nicole Bando, APD & IBCLC, March 15, 2020
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Nutrition & Immunity
Let’s talk about how you can optimise your nutrition to enhance immunity, based on sound scientific evidence. When it comes to supplementation, there is unfortunately no magic pill known to boost immunity and prevent infection. If anyone is trying to sell you such things, save your dollars and hit up the fresh fruit and vegetable section of your local shops instead. Studies have shown that a daily 200mg dose of Vitamin C can reduce the duration of a cold by about half a day, but there’s little other evidence to encourage vitamin or mineral supplementation unless you have a true deficiency, as diagnosed by a medical professional.

What is the immune system?
Put simply, the immune system consists of a multitude of organs, cells and proteins designed to fight infection (microbes). Skin is the body’s first barrier and other defences include the gut microbiome, mucous, saliva, tears, enzymes and stomach acid. The bone marrow, spleen and lymphatic systems all form part of our immune system.

White blood cells are made in the bone marrow and certain types, such as T and B lymphocytes move through the bloodstream and tissue looking for microbes (viruses, bacteria, fungi, parasites) to attack. These cells have ‘memory’ of microbes they have encountered before, helping your immune response to react more quickly to repeat infections.

The immune system also produces antibodies, specific proteins made to fight a foreign body or antigen. Antibodies attack and destroy these foreign invaders with the help of other cells and chemicals. For more information, click here:

What we know:

To be clear, the best methods to stay healthy are as per CDC and WHO guidelines: frequent & effective hand washing, avoid touching your nose and face, avoid close contact with anyone demonstrating flu-like symptoms, seek medical advice early if you develop symptoms and cover your nose and mouth if coughing and or sneezing. Latest updates here:

Is it safe to breastfeed?

If you are a breastfeeding mother, it is safe for you to continue doing so even if you have Coronavirus. You are producing vital secretory IgA antibodies (and myriad immune factors) that will transfer via the breastmilk to your baby to provide immune protection and optimise baby’s immune response. Wear a mask around your baby, wash your hands with soap regularly, including before breastfeeds. If you need to be isolated from your baby, it is safe to express your breastmilk for your baby to drink. Remember that any amount of breastfeeding confers immune benefits, so babies who are mixed fed will also receive protective immune factors. Click here:

A word on malnutrition:

There is evidence to show that malnutrition reduces immunity and can increase risk of infections. Malnutrition may occur in vulnerable groups, such as the elderly or those with multiple medical conditions, or the very underweight. It is also possible to be malnourished at a high body weight due a high energy but low nutrient intake. These individual situations require attention from both a doctor and dietitian. If you are fit and well and healthy, look out for those in our community who may be at greater risk and would benefit from a cooked meal or help with their food shopping. If we can shop as per usual and avoid panic buying, there is more than enough nutrition (and kindness) to go around.

Which nutrients?

These key nutrients have been shown to have a role in immunity:

• Vitamin B6  (breads, cereals, vegetables, eggs, fish): involved in red blood cell formation and metabolism of protein
• Vitamin C (citrus, tomatoes, broccoli, berries): antioxidant, involved in collagen, maintaining teeth, bones, gums and promotes wound healing.
• Vitamin E (peanut butter, almonds, sunflower oil and seeds): antioxidant
• Magnesium (whole grains, legumes, nuts, seeds)
• Beta-carotene (carrots, sweet potato, green leafy vegetables): coverts to Vitamin A (retinol), assists with healthy growth, vision, skin and mucous membrane (part of body’s defence against germs) integrity
• Zinc (whole grains, dairy, red meat, legumes, nuts): wound healing, forms part of enzymes (some involved in immune health)
• Vitamin D (oily fish, eggs, margarine, best source: sunlight): bone health, healthy cell formation, immune function.
• Antioxidants are chemicals found in fruit, vegetables, wine and tea and are part of our body’s defence system against free radicals (unstable molecules that cause damage to proteins such as DNA and cell structures).
• Unless you are deficient in these nutrients, taking supplements is of no benefit. As you can see, these nutrients cross a variety of foods from all group (dairy, meat/alternatives, veg, fruit, whole grains), so a balanced diet is key. Remember that small steps to increase your intake of these foods are all positive.
• Click here for a sample balanced day: 

What is the bottom  line?

General health:

• Practice good hand hygiene and social distancing.
• Rest and get plenty of sleep
• Exercise
• Try to minimise stress levels
• If you drink, do so moderately, avoid if pregnant/breastfeeding. Revised NHMRC Guidelines suggest less than 10 standard drinks per week 
• Don’t smoke

And when it comes to nutrition?

• Eat the rainbow! Aim for 5 serves of vegetables and 2 of fruit (frozen and canned are good options) 
• Include wholegrains: breads, cereals, rice, pasta, oats, quinoa, barley, etc.
• Include lean sources of protein: meat, chicken, soy, eggs, nuts, dairy, fish, legumes
• Add small amounts of good fats, such as nuts, seeds, avocado, olive oil
• Reduce your intake of sugary foods and drinks
• Get your daily dose of Vitamin D in the sunshine at safe times or via supplementation if your levels are low (a blood test will show this)
• Here’s a recipe to boost your intake of nutrients

Other references: Saxelby, C 2012, Catherine Saxelby’s Complete Food and Nutrition Companion, Hardie Grant Books, Melbourne.