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  • Writer's pictureDr. Courtenay Boer

Top 5 Lifestyle Tips for Cold & Flu Prevention

Updated: Jan 14, 2019

As we head into cold and flu season, it’s important to do what we can to strengthen our immune system and to think preventatively. We’ve come off the heels of a bad flu season last winter – in fact, the U.S. CDC categorized the 2017-2018 flu season as “high severity.” So what can we do this year to decrease the severity and protect ourselves? By taking everyday preventative actions and creating healthy habits (turns out Mom was right – wash your hands!), we can stack the odds in our favour for a healthy winter season! In addition to these prevention tips from Health Canada, here are my top 5 tips:

1. Prioritize sleep:

This one may seem pretty obvious, but it’s often easier said than done. Prioritizing sleep is vital during the winter months, as lowered immune function has been shown in those suffering from insomnia or sleep deprivation (1, 2). Studies have found that insufficient sleep is linked to the suppression of many types of white blood cells (lymphocytes) (3), which make up a large part of our immune system. Additionally, poor sleep has been correlated with increased pro-inflammatory cytokines such as IL-6 (4). Given this, it probably comes as little surprise that poor sleep is associated an increased risk of both the common cold (rhinovirus) (5) and pneumonia (6). Not only is sleep important for cold and flu prevention, it is equally important if you are planning on receiving the flu vaccine. Lower antibody titers post-vaccination were found in a group of otherwise healthy college students suffering from insomnia as compared to those without, inferring decreased vaccine effectiveness (7). Keeping sleep as a priority this season will do wonders for your immune system – aim for at least 7 hours (preferably 8) per night!

2. Eat well:

Nutrition is another cornerstone of maintaining a strong immune system. Eating a nutritious, plant-based, whole-food diet and keeping up on hydration is one of the best things we can do for ourselves, while keeping sugary foods to a minimum. We know that bacteria thrive on sugar, and a sugary snack or meal also has been shown to depress the immune system for several hours, making us more susceptible to viral infections as well (8). A Western diet high in refined sugars has been linked with increased inflammation and reduced immunity (9). Let food be thy medicine by incorporating a varied diet abundant in vegetables, legumes, lean meats and some fruit to provide essential nutrients for our natural defence system, and drink plenty of water throughout the day.

3. Exercise:

While our instinct may be hibernation when temperatures start to dip, it’s important to keep moving during the winter months! Numerous studies have shown exercise to modulate the immune system (10,11). Moderate exercise is known to be beneficial for immune health, as opposed to sedentary lifestyle (12). A good goal is to aim for at least 10,000 steps per day or 30 minutes of moderate-intensity exercise that causes you to sweat.

4. Nature time:

Spending time in nature has many incredible benefits, one of which is its effects on the human immune system. In Japan, the practice of forest-bathing is known as shinrinyoku, and has been shown to increase the number and activity of a type of white blood cell known as Natural Killer (NK) cells (13, 14), which are some of our first responders during a viral infection. Interestingly, these studies found that spending time in a city environment did not increase NK cell activity. This suggests that immersion in forest environments has the potential to enhance our immune system. So get outside and take a walk in the forest – your body and mind will thank you for it!

5. Stress management:

While short-term stress can enhance our immune response, the long-term stress that most of us experience can down-regulate our immune system, and cause dysregulation in the balance of our innate and adaptive immune responses (15). While learning to cope with stress and finding balance can be difficult (I could write an entire series of articles on it!), it is a practice worth pursuing. Discovering ways of managing stress that will work well for you is completely personal – it could be getting out into nature, a good laugh with a friend, going for a run, having a cup of tea, reading a good book, or a mindfulness or meditation practice. It doesn’t have to be complicated or time-consuming; it is more about giving yourself permission to rest and slowing down when you can.

Healthy lifestyle and nutritional practices are foundational to support the innate and adaptive immune system through cold and flu season. Targeted supplementation with nutritional and herbal allies can be layered in when necessary (see my previous post on Vitamin D), however these are supplemental! Incorporating these small practices into daily life can help us stay strong and resilient.

Wishing you health and wellbeing this season!


1. Irwin, M. (2002). Effects of sleep and sleep loss on immunity and cytokines. Brain, behaviour and immunity, 16(5): 503-512.

2. Taylor, D. et al (2010). Insomnia as a Health Risk Factor. Behavioural Sleep Medicine, 4: 227-247.

3. Savard, J. et al (2003). Chronic insomnia and immune functioning. Psychosomatic Medicine, 65(2): 211-221.

4. Burgos, I. et al. (2006). Increased nocturnal interleukin-6 excretion in patients with primary insomnia: a pilot study. Brain, behaviour and immunity, 20(3): 246-253.

5. Patel, S. et al. (2012). A Prospective Study of Sleep Duration and Pneumonia Risk in Women. Sleep, 35(1): 97-101.

6. Cohen, S. et al. (2009). Sleep Habits and Susceptibility to the Common Cold. Arch Intern Med, 169(1): 62-67.

7. Taylor, D. et al. (2017). Is Insomnia a Risk Factor for Decreased Influenza Vaccine Response? Behav Sleep Med, 15(4): 270-287.

8. Sanchez, A. et al. (1973). Role of sugars in human neutrophilic phagocytosis. The American Journal of Clinical Nutrition, 26(11): 1180-1184.

9. Miles, I. (2014). Fast food fever: reviewing the impacts of the Western diet on immunity. Nutrition Journal, doi: 10.1186/1475-2891-13-61.

10. Venjatraman, J. and Fernandes, G. (1997). Exercise, immunity and aging. Aging, 9(1-2): 42-56.

11. Batatinha, H. et al. (2018). Nutrients, Immune System and Exercise: Where it will take us? Nutrition,

12. Nieman, D. (1997). Exercise immunology: practical applications. International Journal of Sports Medicine, 18(1): 91-100.

13. Qing, L. (2010). Effect of forest bathing trips on human immune function. Environmental Health and Preventative Medicine, 15(1): 9-17.

14. Tsung-Ming, T. et al. (2018). Health effects of a forest environment on natural killer cells in humans: an observational pilot study. Oncotarget 9(23): 16501-16511.

15. Dhabhar, F. (2014). Effects of stress on immune function: the good, the bad, and the beautiful. Immunologic Research, 58(2-3): 193-210.


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