Nutrition And Immune Health
It will come as little surprise to actively practicing dietitians, but it is worth reiterating that the COVID-19 pandemic has brought about a genuine and lasting surge in public curiosity surrounding diet and immune health.
Confirmed by a recently published report by Pollock Communications and Today’s Dietitian which surveyed dietitians on their clients most pressing concerns and curiosities, it is a topic which we should all feel comfortable speaking about.
“Moderate-quality evidence exists from both human intervention and observational studies to suggest that diet and individual nutrients can influence systemic markers of immune function and inflammation” -Nutrients 2020
So what is the nature connection between nutritional status and immune health for an otherwise healthy individual? Are there certain foods or nutrients that could play a meaningful role in “boosting” immunity? These are the types of questions that the modern client is eager to engage with, so let’s take a closer look at how we can address these concerns in an evidence-based fashion.
Nutrients Of Interest
Vitamin D: Vitamin D has long been considered a nutrient of interest in the world of immune health and may have a role to play in the body’s response to both viral and bacterial infections.
It’s also a nutrient of particular interest in the Canadian context both due to a lack of sun exposure and the fact that fatty fish ( ex; salmon) are the only truly significant source in the food system.
Fish intake is an effective way to boost vitamin D status, but consuming fish at recommended levels (150 grams weekly) is not likely to be sufficient.
Prebiotic-Rich Foods: The human gut microbiome has a significant role to play in supporting the immune system. Many “healthy” bacterial species contribute to anti-inflammatory messaging through the digestive system and in turn play some role in dictating the body’s resilience to sickness and infection.
As a result, I believe that a discussion of pre-biotic rich foods, in a similar vein to my last post, is a warranted and reasonable conversation to have with any client interested in the concept of immune health. If you’d like to learn more about the relationship between gut bacteria and immunity, I recommend this 2019 paper published in the Immunity journal.
Zinc: While zinc does not jump out as the most prominent nutrient of public health concern, it’s possible that up 35% of Canadians in certain demographics may not consume enough from their diet.
This could be relevant in the context of immune health because adequate zinc status is considered important to maintain homeostasis or balance within the human immune response.
Aside from beef and poultry, the nut, seed and legume families of foods tend to be the highest dietary sources of Zinc. Nuts, seeds and legumes are also among the most healthful high fibre foods and have high potential to contribute to a diverse, healthy gut microbiome as per the previous discussion point.
Application To Your Clients
My primary messaging to clients is that good immune health stems from the same place that good overall health does, a strong dietary pattern. While the specific foods and nutrients identified this post may garner extra attention for their role in immune health, their overall functionality remains unquestionable even if they didn’t!
With that said, after reading today’s post you will hopefully be better positioned to have this discussion with your clients to support those who might be uniquely intrigued by the nutrition/immunity discussion.
If you are looking for further reading in this subject area, I recommend this 2019 paper out of Frontiers In Immunology which takes a closer look at the immune-supporting role of other nutrients/supplements including omega-3 fatty acids, green tea and probiotics.