Taking care of your Immunity

Usually, the winter months have to start rolling in before any of us think about protecting ourselves from colds and the flu. This year has been a bit different. Talks of keeping well and boosting your immune system have flooded social media ever since a particular virus hit our shores. While some might be stocking their pantries with supplements and health tonics, others might be scratching their heads thinking “can diet and lifestyle really boost my immunity?”.

Researchers have the same question, but the complexity of the immune system makes it a difficult one to answer. It is even hard to define what immune-boosting looks like- simply having more immune cells is not always a good thing. Like most things in life- it’s about balance. While there isn’t definitive evidence that we make our immune system go above and beyond, there are steps we can take to simply support healthy immune function. And these steps are pretty much the same as the regular healthy living guidelines


It is essential that your body’s defenders have what they need. Eating a balanced diet high in vegetables and fruits will help you with that. Listed below are nutrients that play an important role in immunity and as such we should ensure adequate amounts of them in our diet

  • Vitamin C: capsicum, citrus fruits, broccoli
  • Zinc: beef, poultry, nuts and seeds, oysters
  • Iron: beef, shellfish, tofu, legumes (Note: The iron in meat and seafood is absorbed better than vegetarian sources of iron. You can increase absorption of vegetarian sources of iron by combining it with vitamin-C containing foods)
  • Vitamin B6: pork, poultry, fish
  • Vitamin E: almonds, peanuts, sunflower seeds
  • Magnesium: almonds, pumpkin seeds, spinach, black beans

Keep in mind that having excessive amounts of particular nutrients has not been shown to super-power our immune systems. It is really about having a variety of foods year-round for a mix of vitamins and minerals (not just the ones listed above) to ensure that your immune system is always prepared.


In general, it is recommended you should aim to meet your requirements through food, as food provides you with a balance of nutrients. Supplements are only recommended for those who are at risk of deficiencies in order to safeguard not just their immune but overall health. Vegans, for example, should be supplementing with B12. Supplements may also benefit older people because aging can decrease the body’s ability to hold onto nutrients and may decrease appetite putting you at risk of deficiencies.

If you are considering taking a supplement it is best to talk to your doctor or dietitian before you do so. If you do take over the counter supplements choose ones with a low dose, as too high a dose can be harmful.

And those herbs in health food stores? While the prospect of enhancing your immunity with some exotic herb grown in a tropical land does sound enticing, the evidence for them is quite thin. That being said, these herbs are unlikely to cause harm (all they might do is leave a dent in your wallet).


Your immune system is another reason to get physical. Exercise improves circulation of immune cells and has anti-inflammatory effects. Lockdown or not, there are plenty of ways to get physical without a gym. Thankfully, we can still go outside, get some fresh air and go for a run or a walk. And if it gets a bit too cold for you and you’d rather stay indoors, fear not! The internet is absolutely packed with videos and guides on exercising at home no matter what skill level you are at. Aim for 30 minutes of moderate intensity exercise per day. For more information visit our physical activity page here.

Alcohol and Smoking

Smoking and alcohol can put a damper on our immune system. The current recommendation is to avoid smoking. If you do choose to drink it is recommended that women stick to no more than two standard drinks per day, with at least two alcohol-free days per week and for men stick to no more than three standard drinks per day and also observe two alcohol-free days per week. For more information about alcohol drinking recommendations visit our page here


You don’t need an expert to tell you that a good night’s sleep leaves you feeling refreshed, and now there is mounting evidence of its importance in immune health. A study found that amongst a group of people administered the rhinovirus (the virus that causes the common cold), those that slept less than 7 hours were 3 times more likely to develop a cold. While we don’t fully understand the pathways, researchers have found a link between sleep and cytokines which are messengers of the immune system.

It is recommended that adults up to the age of 65 get 7-9 hours of sleep and those over 65 should get between 7-8 hours. Children need more, depending on their age. Sticking to consistent bedtimes and waking times, avoiding stimulants such as caffeine four to six hours before bedtime, and creating a quiet, dark, and cool environment in your bedroom can help you get some quality shut eye.


Stress seems to be a major by-product of life in the 21st century. Add in a global pandemic to the mix and things get taken up a further notch. With the many different types of stressors present and the different responses people have, stress can be a challenge to study. Despite that, growing evidence suggests that chronic stress can affect immunity. Taking time to relax, using mindfulness techniques and spending time with family and friends (virtually if needed) can increase your ability to cope with stress.

All in all, you’ve probably heard most of these messages before, and for good reason. Diet, stress management, exercise and sleep are mainstays not only for a healthy immune system but help overall health. The best way to stop the spread of germs is by practicing good hand hygiene, keeping up with vaccines, staying at home when you are sick and in light of the COVID-19 situation adhering to the alert levels.



Chandra, R. K. (1997). Nutrition and the immune system: an introduction. The American Journal of Clinical Nutrition, 66(2), 460S-463S.

Cohen, S., Doyle, W. J., Alper, C. M., Janicki-Deverts, D., & Turner, R. B. (2009). Sleep habits and susceptibility to the common cold. Archives of Internal Medicine, 169(1), 62–67.

Division of Sleep Medicine at Harvard Medical School. (n.d.). Twelve Simple Tips to Improve Your Sleep | Healthy Sleep. Retrieved December 19, 2023,

Harvard Health. (n.d.). Micronutrients have major impact on health. Retrieved April 20, 2020, from

Havard. (n.d.). Zinc | The Nutrition Source | Harvard T.H. Chan School of Public Health. Havard T.H Chan School of Public Health. Retrieved April 20, 2020, from

Havard Health. (2020). How to boost your Immune system. Havard.

Irwin, M. (2002). Effects of sleep and sleep loss on immunity and cytokines. Brain, Behavior, and Immunity, 16(5), 503–512.

Ministry of Health NZ. (n.d.). Alcohol. Retrieved April 20, 2020, from

Ministry of Health NZ. (2019). The four food groups.

National Sleep Foundation. (n.d.). How Much Sleep Do We Really Need? Retrieved April 21, 2020, from

Nieman, D. C., & Wentz, L. M. (2019). The compelling link between physical activity and the body’s defense system. In Journal of Sport and Health Science (Vol. 8, Issue 3, pp. 201–217). Elsevier B.V.

Pressman, S. D., Cohen, S., Barkin, A., Miller, G. E., Rabin, B. S., & Treanor, J. J. (2005). Loneliness, social network size, and immune response to influenza vaccination in college freshmen. Health Psychology, 24(3), 297–306.

Last modified: December 19, 2023