How to Boost Your Immune System

General Medical

Dr. Sam Hay

It was the new buzz phrase over Winter.

“Boost your immunity.”

But what does that really mean? What is your immunity and is it possible it can be “boosted”? And more importantly in these budget conscious times, do the best “immunity boosters” come with a price?

The immune system is your body's defence force. It protects against disease. It’s a complex system of interacting cells and organs that communicate by chemical messages to keep the body safe.  It fights infections, toxins, and foreign substances. It includes the red and white cells in our blood; organs such as our spleen and lymph nodes; and countless processes such as the production of extra mucous (‘snot’) from our nose with a cold. The enemy may be bacteria or viruses, or more rarely, even a fungus or a parasite. While the immune system seems rather nebulous, it’s incredibly powerful. But, if there’s a kink in the armour of that defence force; if parts of it fail; then an ‘enemy’ gets through – and you get sick.

When there is talk about “boosting the immune system” we are talking about ways to “keep the guard up”.

So what can we do?


The first thing you can do is look after yourself! Get those regular check ups and manage any underlying illness you have. Let your body put all of its energy into being well, not fighting disease.

Conditions such as diabetes or heart disease, even simply being overweight or hypertensive, lower immunity to some degree. Then there are the medications we need for treatment – sometimes they too can affect the immunity to even a small degree. So concentrate on managing any illness or disease as best as you can, or better still, take every step to prevent it in the first place!


Trust me, it’s a challenge for me too at 05:30am – but here is a fact that might help throw back the doona!

Research shows people who exercise regularly have stronger white blood cells (those cells that help fight the bugs). We also know that people who exercise get endorphins and hormones released that reduce depression and improve sleep – proven immune boosters. And, yes you guessed it, being well rested also helps keep our immune system at its peak.


White blood cells love good nutrition. Viruses, bacteria, bugs all thrive when there’s no nutrition around. It’s a no brainer. It’s all about a healthy balanced diet – drawing from all good groups so you get the right mix of vitamins, minerals, mirco-nutrients, and macro-nutrients.  And eat as much fresh food as you can – rather than over processed junk foods.

BUT, there’s a butDon’t get sucked into the “Superfoods”. “Superfoods” are touted to be high in valuable antioxidants, which include vitamin A, the carotenoids such as beta-carotene, as well as vitamins C and E. Many other compounds found in food, especially vegetables and fruits, also have antioxidant properties. There’s widespread belief that antioxidants can prevent cancer and cardiovascular disease by augmenting the body's ability to dispose of ‘toxic free radicals’.

Whilst studies have consistently shown that diets high in vegetables and fruits (that are rich in antioxidants) are associated with a reduced risk of cancer and cardiovascular disease, it’s not as simple as taking extra in tablet form.  These studies are not that easy to conduct because there are many other possible substances that could be having an effect – such as other non-vitamin antioxidants, other compounds in vegetables and fruits such as flavonoids, substitution of dietary meat and fat with vegetables and fruits, or healthy lifestyles in people taking fruits and vegetables. The more robust trials out there have generally not found positive effects. 

The last word on “superfoods”. Vegies and fruit are good for you, and yes, some are higher in anti-oxidants and are important to include in your diet – but they aren’t so powerful that you should drop all your cash on out of season expensive “berries” or expect to feel like wonderwoman cause you’ve bought some sort of exotic Amazonian vegetable. By all means eat them – because they’re good for you – but the idea they are super and offer something above and beyond a good healthy diet with exercise, is a stretch.


I have patients, family members and bloggers I follow who are convinced by the value of “supplements”. There is no medical evidence whatsoever a generally healthy person with an uncompromised immune system gets any benefits from supplements.

If you feel rundown or tired consistently, or feel like you are getting way more colds than your colleagues, instead of self diagnosing, drop in and see your doctor. They can run some blood tests to make sure you are ok. And if there is a problem with your immune system – they can use more proven and reliable methods to bring it back up to scratch.


Water!  Drinking plenty of water is paramount to a good functioning immune system.  This is especially so when we are sick, as the body burns extra water to fuel the fight against infection.

How much is enough? This is an age old question, with a commonly quoted volume of two litres a day. In a nutshell, everyone is different, and we should be aiming to drink regularly through the day, to the point where we have periodic trips to the loo with nice clear pee. For some people they will only need a few glasses on top of their meals; whilst others may need two to three litres worth.

What about alcohol? This is a tricky one. Drink too much and you’ll definitely drop your immune strength. Too much alcohol each day is directly linked to poor sleep, worse mental health, and increased risk of cardiovascular disease and overall mortality. However, there is evidence that small amounts of alcohol can reduce cardiovascular disease and overall mortality risk – and this may relate, at least in part, to how the immune system works. Whilst there are some people who shouldn’t drink at all, it’s widely believed that up to two standard drinks a day is safe, and possibly even good for you!


Don’t want to be the bearer of bad tidings, but even if you have a tip top immune system and are doing everything you can to “boost it” - it is completely normal to get at least two colds a year.

Don’t put yourself in a bubble. While they are far from pleasurable – getting those colds may just save you down the track. Our immune system develops a memory, so if you come in to contact with the same, or similar infection in the future, your body is already primed – it will fight harder and stronger. This is especially advantageous if that future infection is a particularly dangerous or deadly one. Everyone wants to be able to fight those ones off more effectively!


It's proven folks, vaccinations work. I’m a firm believer that everyone needs to be up-to-date with all their shots, and this is especially so for the influenza vaccine (flu-shot). Australia is currently in the midst on one of the biggest influenza outbreaks we have ever seen. But what frustrates me is that people continue to ignore the fact that influenza kills. And, it also doesn’t discriminate.  The young, elderly, pregnant, and otherwise unwell at most vulnerable. But in recent years it’s claimed the lives of countless fit and healthy adults. And before you argue it gives you a ‘cold’ – it doesn’t!

Bottom line. See your doctor and get your shots!  Especially the flu-shot.

BMedSci, MBBS(Hons), FRACGP, GDipSpMed, DCH
Director Your Doctors®


Please note: Dr. Sam's blog is general advice only. For further information on this topic please consult your healthcare professional.

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