Weekly Immune Instalments

immune healthAt Perth Health and Fertility, we are committed to sharing as much health advice as possible to promote health and wellness in the community. At this time, more than ever, it is important for us to share this research and knowledge with you all. For this reason, we are going to be releasing weekly updates that you can share within your network, so that as a community, we can help tackle this challenge together! We’ll continue to update this page (as well as our Facebook and Instagram) as we go.

Green Tea

Did you know green tea has been extensively studied for its strongly anti-viral effects? In fact, individuals who drink green tea are at decreased risk of contracting both influenza and the common cold. This is because green tea contains a special type of compound called catechins, which have strongly anti-viral effects. In one study, residents in an aged care facility who gargled 1/2 a cup of green tea three times daily were 5 times LESS LIKELY to catch the flu, than those who didn’t. A further study of healthcare workers showed that those consuming catechins from green tea were less likely to contract the influenza virus than their colleagues who didn’t. We’ve linked to these studies HERE and HERE respectively.

Whilst green tea hasn’t been researched for COVID-19 specifically, it is an easy and practical habit you can incorporate into your daily routine to reduce your risk of catching a viral illness. The wonderful thing about green tea is that it is widely available, cheap and has successfully showed its efficacy as an anti-viral agent across many studies. Now is the time to be proactive, and drinking or gargling green tea is a great place to start.

Note: The optimal method for brewing green tea is to boil the kettle, let it cool for 2-3 minutes and then pour the hot water over the tea (ideally, the water should be around 85°C). Steep for 3-4 minutes, and enjoy.

Vitamin D
Did you know Vitamin D is one of the most important nutrients for your immune system? When we talk about the immune system, we often think of zinc and vitamin C, but adequate vitamin D is essential for your body’s immune response and resistance to infection! Not only has vitamin D supplementation been shown to reduce your risk of catching a cold, but individuals with lower vitamin D levels are more likely to experience severe respiratory tract infections (such as pneumonia or influenza A) with symptoms persisting for longer periods of time. In fact, one group of researchers looked at the results of 25 studies conducted across 14 countries and found that vitamin D supplementation protects against acute respiratory tract infections, particularly among those who are deficient – If you suffer recurrent respiratory infections, perhaps ask your doctor or naturopath to check your vitamin D levels at your next visit.
Research suggests vitamin D acts on multiple levels of the immune system to improve your defences. For example, on a physical level, it is involved in the production of ‘defensins’ for your mucous membranes. Defensins are anti-microbial proteins that live in the mucosal lining of your nose, throat and lungs, to help keep the bad bugs out! Vitamin D also enhances the body’s innate immune response, meaning it helps your immune cells digest and destroy bacteria and viruses to keep infections at bay.
In Perth, we make most of our vitamin D from the sun between November to April, if we can get outside and in the sunshine during the middle of the day. This is also the time we are most likely to get burnt, so it is important to monitor your exposure to prevent sun damage. The amount of sunshine you can tolerate (as well as how much time you need in the sun to make vitamin D) is largely dependent on skin tone – those who are very pale may need only 5-10 minutes of sun exposure at the peak of the day to get their vitamin D levels up, whilst those who tan more easily or have darker skin will require longer (10 minutes to an hour or more, depending on skin tone). It is essential to monitor your exposure though so you DON’T GET BURNT! If you can’t regularly get out in the sunshine with your skin exposed, speak to a qualified healthcare practitioner about whether a vitamin D supplement might be right for you and at what dose. 
Beta Carotene

Bright orange fruit and veggies, such as carrots, sweet potato, pumpkin and rockmelon, contain a compound called beta-carotene, which gives them their lovely vibrant hue. Interestingly, dark green leafy veggies are also high in beta-carotene, but they get their colour from another compound called chlorophyll. Beta-carotene is an incredibly important nutrient for your immune system, as it is a precursor to vitamin A. In the body, we convert beta-carotene into vitamin A, which keeps the mucous membranes in our nose and respiratory tract strong so they can keep the bad bugs out! Essentially, it’s a bit like the glue that keeps our mucous membranes strong and resistant to infection.

Research suggests vitamin A deficiency is a major risk factor for respiratory tract infections, particularly in children. Not only does vitamin A deficiency increase your risk of infection, but it also impairs cellular immune responses, meaning your white blood cells don’t respond as effectively to bugs and germs. This means beta-carotene and vitamin A support both our physical barriers against infection (our mucous membranes) as well as our chemical barriers (our immune cells).

A couple key points on getting the most out of your beta-carotene:

  • Firstly, consume beta-carotene multiple times throughout the day, from a variety of sources. This could include carrots, sweet potato, papaya, dark green veggies, rock melon etc.
  • Steaming or roasting your carrots and sweet potatoes makes the beta-carotene more bioavailable, so consider cooking these veggies first.
  • Beta-carotene is fat soluble, so include a source of healthy fats to maximise your absorption. This could be some avocado or olive oil with your leafy green salad, or perhaps some hummus with your carrot sticks.
  • To convert beta-carotene into vitamin A, we need enough zinc on board. Zinc-rich foods include beef, eggs, pumpkin seeds, chicken, legumes, cashews and oysters. If you’re not sure whether you or your children are meeting your recommended daily zinc intakes, have a chat to your naturopath.

Remember the old cod liver oil your grandparents took? They were given it to protect themselves from respiratory infection because cod liver is a good source of vitamin A. Like all vitamins, vitamin A needs to be properly prescribed by a health practitioner, but the good news is, you can enjoy your carrots, pumpkin, sweet potato etc and get a wonderful dose of beta carotene!


Did you know sleep is an incredibly important albeit often overlooked aspect of our immune health?

According to researchers, those who don’t get enough sleep or who suffer poor quality sleep are at increased risk of infection, particularly to viruses such as the common cold.
Researchers have found that insufficient sleep reduces both the number and activity of important immune cells, such as our T-helper cells and natural killer cells, leaving you more susceptible to infection. Many of us follow our natural instinct to sleep more when we are unwell, but it is equally important we get enough quality sleep day-to-day to help maintain a strong immune system!

In one study, researchers took a group of 153 adults and monitored their sleeping habits over a two-week period. The individuals were then quarantined and given nasal drops containing rhinovirus (the virus responsible for the common cold) – Interestingly, those who had an average of less than 7 hours sleep per night were almost three times as likely to develop a cold than those who slept 8 hours or more. The researchers concluded those with shorter sleep duration and poorer sleep quality were more susceptible to infection following exposure to the virus. For those who are interested, we’ve linked the study here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2629403/

For adults, we recommend at least 8 hours of sleep a night and encourage our patients to be in bed by 9:30 PM. Children need more sleep, and teenagers need at least 9-10 hours a night, as their bodies are busy growing and developing. If your regular schedule has gone out the window lately, one thing we strongly encourage you to maintain is a great sleeping routine. Sticking to the same pre-bedtime routine each night and ensuring your room is cool, dark and quiet are two key steps you can implement to reduce the time it takes for you to fall asleep and to improve your sleep quality. If you find your sleep is disturbed and you can’t quite find a good rhythm, speak to your naturopath about how we can support and improve your sleep naturally


We’ve all heard eating too much sugar suppresses our immune system, but what does the research say? Interestingly, the research is pretty clear on this one – the higher our blood sugars, the worse our immune function and the more susceptible we are to infections. This is why it is ESSENTIAL we are all taking the steps necessary to keep our blood sugars stable throughout the day. But first, let’s look at why:

Neutrophils are a type of white blood cells that engulf and digest the bugs and viruses responsible for infection. Essentially, they ‘neutralise’ potential pathogens (bugs and germs) and are a key component of the body’s immune response. When we consume simple sugars (like those found in white sugar, juice or honey), our blood sugars start to rise quickly. As our blood sugars rise, our neutrophil activity declines, meaning they are less responsive to bugs and germs. In fact, researchers have found that consuming just half a glass of orange juice by itself impairs immune responses by up to 50%, and that full immune function does not recover for up to five hours! Unfortunately, jam on toast, a sugar in your tea, a cookie from the work kitchenette or a bowl of ice-cream after dinner are not just a sweet treat – sadly, they impair your body’s ability to fight infection. In the current climate, we need our immune systems firing and certainly can’t have them functioning at only 50%.

So how can we anchor our blood sugars? We’ve listed some key steps for you below:
🥕 Firstly, avoid added sources of sugar, such as those found in cereals, jam, biscuits, muffins, lollies and soft drink.
🍓 Check out the Sweet Treats section on our website for some recipes that won’t wreak havoc on blood sugars.
🐟 At every meal, anchor your blood sugars with a source of protein, as protein helps keep our blood sugars balanced. This might look like eggs and grilled veggies for brekky or maybe some muesli with nuts, seeds and natural yoghurt; lentil soup for lunch; hummus and carrot sticks for a snack; and some chicken or fish with a big serve of veggies for dinner. For more ideas, chat to your naturopath.
🥑 Lastly, include some healthy fats and a big serve of veggies (or some fruit) with your meals. Together, healthy fats and fibre from fruits and veggies help slow the rate at which your blood sugars rise. Healthy fats include things like extra virgin olive oil, raw nuts or seeds, oily fish and avocado.

Remember, it’s not just what we eat, but what we eat it with – A lovely piece of fruit contains lots of vitamins, minerals and fibre, and if we pair it with some protein or healthy fats, we’ve anchored our blood sugar – this is why a whole apple with some almond butter is SO much better than apple juice alone (as juicing and processing removes the fibre and much of the vitamin content as well).


It is so important that we as a community do everything in our power to #flattenthecurve. Whilst you or your family may not be in a high risk category, the more we can reduce transmission, the less strain we will place on our hospital beds, frontline staff, medical resources and economy. This is why it is SO important that we all do everything in our power to minimise both our risk of exposure as well as our risk of passing any potential illness onto others.

Please share these tip with anyone you think could benefit from then, as the more we can spread easy, practical and proactive advice, the better our communities will be in the long-run. Make sure to follow our Facebook page as well, so you don’t miss our next Immune Instalment.

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