With coronavirus all over the news and hand sanitiser selling out quicker than discounted Easter eggs, it’s topical that our next blog is looking at how the things we eat, and drink can affect our immune system. It goes without saying that basic hygiene should be everybody’s priority in protecting our immune systems from the nasty stuff, but let’s take a look at what research is out there regarding nutrition and immunity.
In 1747 James Lind, referred to nowadays as “The Father of Naval Medicine” conducted an experiment on British sailors who were suffering from nasty bouts of scurvy, showing how eating lemons and limes reduced symptoms drastically. Indeed, scurvy is caused by a Vitamin C deficiency which sailors were experiencing due to a lack of fresh fruit and vegetables on their voyages. Lind’s experiment lead to the inclusion of limes as a staple in every sailor’s diet and subsequently birthed the nickname given to British sailors at the time… Limeys!
There are dozens of micronutrients (vitamins and minerals) which our body can’t synthesise in sufficient amounts and we must therefore obtain from our diets to avoid deficiency and subsequent health issues . Here we’ll look at three in particular, what the research says and how you can obtain them through your diet.
Involved in hundreds of biochemical reactions within your body, Vitamin B6 is necessary for proper immune function as it aids in the production of antibodies needed to help fight off infection . A deficiency of the vitamin can also impair production of Interleukin-2 which is a protein responsible for instructing white-blood cells during an immune response to bacteria or infection [3, 4].
Humans are unable to synthesize Vitamin C as we lack a specific enzyme involved in the biochemical pathway to create the nutrient  and indeed, Vitamin C deficiency was listed as the 4th most common micronutrient deficiency in the US in the Centre for Disease Control’s 2012 report . A deficiency in Vitamin C can lead to breakdown of epithelial barriers which protect from invading pathogens and through other mechanisms, can impair the capabilities of our immune system to destroy harmful bacteria .
Zinc is a multi-functional mineral in humans and plays a number of critical roles in our body - as a catalyst for enzymic reactions, in the development of cellular structures and in regulation the internal conditions of our body (homeostasis) . Zinc deficiency not only affects our innate immune system (the first line of defence against infection) through impaired white blood cell function, but also our acquired immune system (our ability to respond and fight off infection from previously encountered pathogens) . Put simply, without sufficient zinc, our bodies cannot create new healthy cells.
The list of vitamins and minerals involved in our immune system is long and complex. However, hopefully you now have a basic insight into the importance of various macronutrients, not just for our immune system but for basic bodily functions. Ensuring your diet is varied and full of fruits and vegetables should keep you covered for most vitamins but ensure you’re aware of where you can obtain sufficient amounts of the less common nutrients such as Zinc which we discussed above.