Woman sneezing in a tissue in the living room

5 Ways To Help A Sluggish Immune System

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Your immune system is almost beyond comprehension. It masterfully keeps you free from disease and infections. It’s true, nothing is perfect but if you could truly appreciate what it’s doing for you 24/7, having the odd cold or flu is nothing compared to the innumerable other infections and colds you never got.


Chances are, you really only appreciate your immune system when you have a cold or the flu because being sick is so damned miserable.


That’s when you get how awesome your immune system is; keeping you well most of the time and kicking butt when infections hit.


The immune system protects you from almost everything such as viruses, bacteria, parasites, harmful substances from the environment and even rogue cells that are in the early stages of becoming cancerous.


Your immune cells are always on the look-out for other types of cells (skin, blood etc) that have mutated or are growing out of control. Like PAC MAN, they’re out to devour anything that’s seen as a threat.


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5 tips to ‘boost’ your immune system

Like any other cell or tissue, your immune system and its cells need a steady supply of nutrients to be in tip top shape. In fact, nutrition is a critical determinant of immune fitness and malnutrition the most common cause of immunodeficiency worldwide.


Protein-energy malnutrition is associated with  both a significant impairment, and strength of immune response. You don’t only see this in underdeveloped countries either. A chronic, poor intake of calories and protein make your immune system sluggish.


This is seen in anyone whose intake is poor such as the elderly, those with eating disorders, substance use disorders or even those who get too many of their calories from foods of poor nutritional quality (highly processed foods). Heaps of calories but no protein in soft drinks, chips, donuts, cookies, etc.


When it comes to giving your immune system the edge it needs to fight the good fight, a few crucial nutrients, a type of food, and one lifestyle habit comes to mind. Check them out below…


Vitamin D3

Vitamin D has been studied for it’s role in supporting the immune system in its fight against colds and flu. Vitamin D is a pro-hormone which the immune cells can’t get enough of. They purposefully have vitamin D receptors; once docked, vitamin D helps the immune cells to increase their production of some 200 naturally-occurring antimicrobial proteins.


These are like naturally-produced antibiotics which is why vitamin D helps to fight respiratory infections and other pathogens, as well as, cancer cells in their early development. (1, 2, 3, 4, 5).


The vitamin D that is found in a few foods like fish, milk and butter isn’t enough to give you the immune support you need. Supplements are mandatory in this regard. And sorry, any vitamin D you did make from safe sun exposure during the summer will not carry you through the winter.


Vitamin D, Colds & The Flu. Oh My!


Without enough zinc, your body can’t make immune cells properly. And the immune cells you do make can’t work as well; its like they’re sluggish and dragging their feet.


When you don’t get all of the zinc you need, you are at an increased risk for bacterial, viral (colds and flu) and parasitic infections (6, 7, 8, 9).


Interestingly, unlike other minerals such as calcium, phosphorus, magnesium and iron, the body doesn’t store zinc. To get the most from zinc, you need to regularly get zinc from food everyday. This is vital considering that up to 40% of Canadians don’t get the recommended amount of zinc, and your immune system is one of the first to feel the effects!


Think zinc? Think immunity


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Glorious mushrooms, actually I can’t stand them. That’s not entirely true, I do like Shiitake mushrooms. They have a deep flavour profile and the texture when cooked doesn’t make me want to gag.


Some fungi enthusiasts have suggested that mushrooms be their own food group. They are packed with phytonutrients that really support overall health. Nutrition is more than just protein, fat, carbs, vitamins and minerals although ‘shrooms have some protein, minerals and fiber.


Mushrooms of all kinds of potent immune supporting (modulating) compounds that are well known for their medicinal properties including cancer risk reduction and more (10, 11, 12, 13).


If eating mushrooms aren’t your thing, you can get high quality whole foods (essentially ground up mushrooms) supplements or mushroom tinctures which are just as effective. These natural health products still contain the same active ingredients.


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Vitamin A

Vitamin A is best known as retinol and retinal. Because some of the beta and alpha-carotene you eat will be converted into vitamin A, vitamin A is attributed to plant foods rich in carotene such as carrots, sweet potatoes, spinach, kale, squash etc.


Technically this isn’t the best, nor accurate, way to communicate vitamin A nutrition in my opinion. Carrots DO NOT contain vitamin A (retinol or retinal). A relatively large amount of cartoenes (carotenoids) have to be eaten to get the equivalent amount of vitamin A (hint 12 x more). Also, because about 1/3 of us don’t convert carotenes to vitamin A very well, I make a distinction between the two.


Vitamin A, however, is found exclusively in animal foods


When it comes to immunity, vitamin A is essential. This has been know for a VERY LONG time. Your body uses vitamin A to allow immature immune cells to develop into fully functioning, cold, flu and cancer fighting warriors.


Vitamin A is also crucial to maintaining the lining of your sinuses, throat, digestive tract and lungs. The lining of these body parts need to be moist with a nice layer of good quality mucous which acts as a barrier against invading pathogens  (14, 15).


We might think getting enough vitamin A is easy but still, too many Canadians are missing the mark when it comes to getting the recommended amount. Our diets are more processed than ever before and we are eating on the run. Best sources of vitamin A are liver, eggs, milk, fish, cod liver oil, goat cheese and butter.



This one is easy. Get more sleep.


There’s nothing cool or sexy to be burning the candle at both ends or thinking you can do it all on 5 hours of shut eye. You can’t.


Many think it’s an old wives’ tale that if you don’t sleep well, you will get sick, BUT there is some experimental data that shows this is true. The relationship between lack of sleep and our immune systems is not quite as straightforward as mom made it out to be, however. The immune system is pretty complex but good quality sleep is no doubt important for your immune system (16, 17).


Studies show that our fighter cells, the T-cells go down, or get pooped, if we are sleep deprived and of course pro-inflammatory proteins, or cytokines, go up. A lack of sleep and running on empty fumes is yet another form of stress that takes it’s toll on your health over the long run.


If you want to have an immune system to brag about, get more sleep starting tonight.


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Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, mental health.  Follow me on Facebook, Instagram and Twitter.