'You are what you eat.' Anthelme Brillat-Savarin, French lawyer, politician, and famous gastronome

Humans possess two types of immunity: innate and adaptive. Innate immunity is the first-line of defence. When  pathogens  try to enter our bodies defence mechanisms come into play creating protective barriers which can include: 

  • Skin that keeps out the majority of pathogens
  • Mucus that traps pathogens
  • Stomach acid that destroys pathogens
  • Enzymes in our sweat and tears that help create anti-bacterial compounds
  • Immune system cells that attack all foreign cells entering the body

 The second line of defence is our adaptive or acquired immunity. This system learns to recognize a pathogen. It’s regulated by cells and organs in our body like the spleen, thymus, bone marrow, and lymph nodes. These cells and organs create antibodies and lead to the multiplication of immune cells (including different types of white blood cells) that specifically target and destroy harmful substances. 

Our immune system then ‘adapts’ by remembering the foreign substance so that if it enters again, these antibodies and cells are even more efficient and quick to destroy the invader.

Does an Immune-Boosting Diet Exist?

There is no evidence that supports evidence of an immune-boosting diet.  More of a balancing is required. Eating the right nutrients as part of a varied diet is ideal for the health and functioning of all cells, including immune cells.  

We all know food is energy in the form of calories. However, food is much more than that — food is the largest therapeutic toolbox the body has to rely on for ongoing wellness.  There are millions of molecules that act as vital therapy in every bite of food you swallow. When these molecules enter the body, they effect how your cells behave and how you feel. 

Each stage of the body’s immune response relies on the presence of many  different micronutrients to ensure functionality. Nutrients that have been identified as critical for the growth and function of immune cells include vitamin C, vitamin D, zinc, selenium, iron, and protein (including the amino acid glutamine).  They are found in a variety of plant and animal foods. Functional mushrooms and dark coloured fruits and vegetables have come to the foreground as scientists discovered they containing many of the micronutrients our bodies need to maintain optimal health.  

A diet of processed foods can negatively affect a healthy immune system. Unfortunately, the Western diet is full of processed ingredients as well as pesticides that have travelled from field to factory. They are high in refined sugars and unhealthy vegetable oils like corn oil, safflower oil, soybean oil and cottonseed oil that contain damaging omega-6 fatty acids which are associated with increased inflammation. To make matters worse, the western diet is also low in fruit and vegetables – little or no fibre. This type of diet promotes disturbances in healthy intestinal microorganisms, resulting in chronic inflammation of the gut and associated suppression of immunity. 

The microbiome in our gut is a metropolis of trillions of microorganisms or microbes that live mostly in the intestines. It ‘s an area of intense and active research on how vital  the microbiome is to immune function. 

The gut is the major site for immune activity and the production of antimicrobial proteins. What we eat plays a direct role in determining what kinds of microbes live in our intestines.

A high-fiber plant-rich diet with plenty of fruits, vegetables, whole grains and legumes support the growth and maintenance of beneficial microbes. Some helpful microbes break down fibres into short chain fatty acids, which have been shown to stimulate immune cell activity. These fibers are sometimes called prebiotics because they feed microbes. Therefore, a diet containing probiotic and prebiotic foods may be beneficial to gut health. Probiotic foods contain live helpful bacteria and prebiotic foods contain fiber and oligosaccharides that feed and maintain healthy colonies of those bacteria.

 These nutrients assist the immune system in several ways, working as antioxidants to protect healthy cells, supporting the growth and activity of immune cells and producing antibodies.