Your Immune Questions, Answered!

Your Immune Questions, Answered!

Dec 01, 2021

You asked, so we answered: these are the most pressing immunity questions you posed on social media this month, as answered by Dr. Filza Swalah, ND:

  1. Is it true that cold weather makes you more susceptible to getting sick? 

Research shows that cold & dry weather does increase the time a virus can survive outside and can increase the transmission. Also, cold & dry weather can decrease the nose’s local defense system. All in all, cold and dry does have an impact but it is a low impact!1

Reference: Roussel, M., Pontier, D., Cohen, J.-M., Lina, B., & Fouchet, D. (2016). Quantifying the role of weather on seasonal influenza. BMC Public Health, 16(1).

  1. Does sugar weaken my immune system? 

So, your immune cells need sugar for energy, so it can do a good job at discovering and fighting the first signs of infection. But too much sugar actually slows down the white blood cells – the immune system’s important army of fighter cells.1 Too much sugar can create an increased amount of inflammation – slowing down the effectiveness of our fighter cells and weakening the immune response.2 But please don’t start cutting all sugars! Sugars from fruits are beneficial for our immune system because they supply it with potent antioxidants and immune vitamins like Vitamin C!  It’s really the excessive, added sugars – from pop, candy, chocolate, and processed foods that we should be mindful of!


  • Shomali, N., Mahmoudi, J., Mahmoodpoor, A., Zamiri, R. E., Akbari, M., Xu, H., & Shotorbani, S. S. (2020). Harmful effects of high amounts of glucose on the immune system: An updated review. Biotechnology and Applied Biochemistry, 68(2), 404–410.
  • Myles, I. A. (2014). Fast food fever: Reviewing the impacts of the western diet on immunity. Nutrition Journal, 13(1).

  1. Why is vitamin D good for immunity? 

Vitamin D is essential for the immune system. Our immune cells can actually respond to vitamin D.  1

Vitamin D is so important – and studies are continually proving that lower vitamin D status is linked to upper respiratory tract infections AND supplementing with Vitamin D can actually reduce the risk of experiencing at least one small respiratory tract infection. 2


  • Singh Chauhan, V. (2021). Vitamin D and the immune system. Vitamin D.
  • Martineau, A. R., Jolliffe, D. A., Hooper, R. L., Greenberg, L., Aloia, J. F., Bergman, P., Dubnov-Raz, G., Esposito, S., Ganmaa, D., Ginde, A. A., Goodall, E. C., Grant, C. C., Griffiths, C. J., Janssens, W., Laaksi, I., Manaseki-Holland, S., Mauger, D., Murdoch, D. R., Neale, R., … Camargo, C. A. (2017). Vitamin D supplementation to prevent acute respiratory tract infections: Systematic review and meta-analysis of individual participant data. BMJ, i6583.
  1. What is the difference between adaptive and innate immunity? Does it have anything to do with herd immunity? 

Innate immunity is something that is already within the body, something that is present at birth. Adaptive immunity is created when our body is exposed to a foreign substance, like a virus or bacteria. The innate immune function picks up the foreign substance and the adaptive immune function helps create antibodies to fight it off. Our adaptive immunity also remembers previous infections our body has already been exposed. Take chicken pox as an example...once our body has naturally been exposed to chickenpox the first time it’s really rare to get sick from chicken pox again. That’s because our body is already immune to it and has an appropriate immune response for it!

Herd immunity is when a community is immune to a particular infection either from a vaccine or from being infected & then recovering from it.

  1. What are your best products for immune health? 

The best products are those that help with strengthening your immune system, to prevent common colds & flus. Vitamin D and Vitamin C both support the immune system & are top of mind for me and my patients when thinking about preventing colds and flus.

And sometimes life happens and we get sick BUT it’s so important to have the tools on hand to support your immune system and it’s army!  Echinacea is an example of that – it’s used in Herbal Medicine to help fight off infections, especially of the upper respiratory tract & to help relieve cold symptoms.

  1. What do you do when you get sick?

I like to slow down. I take a day off work, drink a ton of warm soups and teas. I like to top up on my immune supportive supplements like Vitamin C and Echinacea.

  1. What impact does stress have on my immunity? Can positive emotions provide a boost? 

Being stressed for long periods of time can prevent the immune system from working as well as it possibly can! Stress causes high amounts of inflammation which suppresses the immune system. Working on stress management and having positive emotions can definitely help. Try deep breathing, meditating, sharing some laughs with your family or friends, and finding hobbies or activities that bring you joy!

  1. How do antibiotics work and what are they good for? 

Antibiotics are great at fighting infections that are caused by bacteria and work by either killing the bacteria or stopping it from replicating in the body. Antibiotics are lifesaving medications and are good for bacterial infections like strep throat. Because cold & flus are caused by viruses, antibiotics aren’t the most commonly recommended medications by family doctors. Another important thing to keep in mind is that antibiotics don’t differentiate between foreign bacteria, like the one that’s causing strep throat – or our gut bacteria that’s helping us digest and absorb nutrients. It kills it all, so it’s important to consider a probiotic after a round of antibiotics – to replenish and restore beneficial gut bacteria!

  1. If hand sanitizer kills bacteria, why do I still have to wash my hands? 

Sanitizers are great at killing certain bacteria, but they do nothing to actually, physically remove the germs from our hands. That is why it’s important to wash hands, because not only it is a great disinfectant it also washes off the bacteria.

  1. How can I take better care of my immune system? 

Be proactive! Nourish your body with antioxidant rich foods like colourful veggies and fruits. Be active! Exercise and movement can reduce stress levels and increase our fighter cells. And get good sleep! While our mind and body are resting, our immune system is patrolling for foreign invaders. And do not forget supportive nutrients like Vitamin D, C and herbs like Echinacea!

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