- Mar 5, 2020
- 4 min read

Biological Self-Defense: Eating to Strengthen Immunity

Updated: Apr 8, 2020

In light of the recently spreading Coronavirus, I wanted to dedicate a post to immune system health. Scientists are rushing to develop a vaccine; in the meantime the only defenses one has are physical barriers (masks, gloves, staying at home) and their own immune system.

Please don't misunderstand me here: I would never claim that proper nutrition alone could prevent contracting an illness. But for the time being, every small preventative measure may as well be taken. Wash your hands, avoid physical contact with others, wear a mask, work from home, eat more carrots and broccoli.

According to the Encyclopedia of Natural Medicine, nutrient deficiency is the most common cause for decreased immune function. This could be due to an insufficient consumption of foods like the ones I'm about to list— but it could also be due to an excess consumption of certain things, such as protein, sugar, alcohol, processed foods that contain yellow food dye (tartrazine), or oral contraceptives. Other factors that can put a strain on your immune system are stress, lack of sleep, lack of exercise, excess weight, and smoking cigarettes.

Considering all of the variables at play here, it should be clear that the information I'm about to provide is not personalized isn't intended to cure or guaranteed to prevent disease. My hope is to provide some tips and context for you, so that you can plan meals and snacks with your immune health in mind, and check yourself for lifestyle habits that may be burdening your immune system. If you are feeling unwell, or if you're embarking on some major dietary or lifestyle change, please do so only with personalized assistance from your physician or a qualified and recommended dietician/nutritionist/naturopath.

That being said, I've compiled the following information in a few ways below: a grocery list of the most helpful foods, their nutrients and what they do for the body, and some nutrient-dense recipes.

Immune-Enhancing Shopping List:

That may be all the information you care to know, and that is fine! If the biological processes interest you, read on. But first, a quick rundown of what exactly the immune system consists of:

The Thymus - a gland between your heart and sternum in which hormones and T cells develop.

The Spleen - a gland between your stomach, lung, and ribcage in which blood is filtered, harmful components are excreted and helpful components are resorbed.

Immune cells aka White Blood Cells aka Leukocytes - There are many types, but I will break them into three categories:

- cells that secrete things: eosinophils, basophils, and mast cells secrete compounds that break down antigens (antibodies) and trigger allergic responses.

- cells that destroy things:

- Neutrophils and macrophages destroy bacteria, tumor cells, and healthy cells that have died.

- Monocytes destroy cellular debris left over after an infection has

cleared up.

- Natural Killer cells destroy cells infected by a virus or cancer.

- cells that both secrete and destroy: T cells (those ones made in the Thymus) do a

little bit of everything, to put it broadly.

And now, a bit about how certain nutrients interact with the above:

Vitamin A & Beta-Carotenes

(Shrimp, Eggs, Cow's Milk / Carrots, Spinach, Sweet Potatoes)

- strengthens skin, internal organ linings, and function of protective secretions

- promotes growth, function, and protection of the thymus

- antioxidant function (protects from cellular damage and dysfunction)

(click here to learn a bit more about antioxidant function and foods)

Vitamin C

(Bell Peppers, Broccoli, Papayas)

- antiviral & antibacterial functions

- stimulates several immune responses

- when consumed with flavonoids, effects of both are potentiated

(flavonoids are antioxidant compounds found in apples, citrus, onions, soybeans and high-quality soy products, coffee, and tea)

Vitamin D

(Salmon, Sardines, Tuna)

- enhances clearance of bacteria

- activates T cells

- protects from autoimmunity

- especially indicated for respiratory infections

Vitamin E

(Almonds, Spinach, Sunflower Seeds)

- increases white blood cell production, response, and function

- prevents free radical damage to thymus

B-Complex Vitamins

(Almonds, Lentils, Sardines, Soybeans, Sunflower Seeds, Tuna)

- a deficiency in B vitamins results in shrinkage of the spleen and thymus, which results in reduced white blood cell and antibody production

Iron

(Lentils, Sesame Seeds, Soybeans, Spinach)

- similarly to a B vitamin deficiency, an iron deficiency can lead to spleen/thymus shrinkage and decreased WBC production and function.

Zinc

(Beef, Lamb, Lentils, Sesame Seeds)

- enhances antioxidant and white blood cell function

- destroys foreign organisms and inhibits growth of viruses

- potentiates benefits of vitamin A

- anti-inflammatory (activates peptide called serum thymic factor)

Selenium

(Brazil Nuts, Salmon, Sardines, Shrimp, Tuna)

- anti-inflammatory (necessary for major enzyme family glutathione peroxidase)

Now that I've stimulated your appetite with the above information, here are twenty-five super simple (<10 ingredients; <45 min cook time) recipes to help keep your immune system up and running: