The lifestyle I have chosen does not lend itself to taking drugs when feeling less than awesome. While there are most definitely instances where prescription drugs are valuable, I am often reluctant to pick up pharmaceuticals to combat a simple cold for fear of what effect they may have upon my body. This aversion to conventional medicines has led me into the dubious world of homeopathic remedies, but the apathy induced by inconsistent results often motivates me to simply ‘tough it out’ and subject myself to the misery and self-pity that result from deliberate inaction. However, the threat of becoming ill is not a losing battle as my life has seen a few lucid moments where adhering to a few simple dietary measures has greatly improved the ability of my immune system and provided me a tremendous amount of relief from the physical and psychological stress of illness.
But, before we get to the ‘eat this, not that’ portion of this discussion, lets quickly review a few important concepts concerning the immune system to help us better understand what we are trying to accomplish in feeding the immune system.
The Immune System in 494 Words
The task of the immune system is to identify and destroy antigens. Antigens are foreign substances that evoke the production of an immune response and antibodies. The body tries to prevent the invasion of potentially harmful invaders through a system of innate defense systems and can also neutralize their impact through the development of certain biological response when their presence is detected. The body accomplishes this Herculean feat through two different immune systems: innate immunity and adaptive immunity.
Humans are born with innate immunity, which includes the physical (skin) and chemical (mucosa) barriers along with various other non-specific internal defenses (inflammation, fever, antimicrobial substances, etc.) that discourage foreign substances from penetrating the body and fight pathogens on the cellular level. Although this first line of defense provides an excellent foundation for which our immune system can function, it is inherently weak and our body must cultivate the ability to defend itself against a more complex variety of invaders. Adaptive immunity provides such ability and allows the body to defend itself against specific foreign substances such as bacteria, toxins, viruses and foreign tissue.
The human body utilizes white blood cells to captain the adaptive immune response through two basic means, cell-mediated immunity and humoral immunity. Cell-mediated immunity, the body’s second line of defense, leverages T cells to help eliminate foreign bodies, direct immune function, and regulate the immune response when antigens have been eliminated. Cell-mediated immunity is particularly effective against intracellular pathogens, cancer cells, and foreign tissue transplants where self cells indiscriminately attack foreign cells to fend of disease.
Humoral immunity, the final line of defense, involves the production of antibodies where B cells respond to the presence of certain antigens with the production of special proteins whose chemical structures neutralize specific foreign bodies. Contrary to cell-mediated immunity, humoral immunity works mainly against extracellular pathogens that work in the fluids outside of our cells while helping our immune system develop immunological memory to facilitate a quicker response in the event of subsequent exposure.
Other important elements of the immune system include the spleen, thymus, lymphatic system and bone marrow. The spleen filters blood to remove “old” red blood cells and is the site where B cells are introduced to antigens to learn how to manufacture the appropriate antibodies. The thymus is important in the ‘education’ of T cells and produces thymic hormones that are thought to aid in T cell maturation. The lymphatic system continuously cleanses the body by clearing excess fluid from intercellular spaces to remove waste, toxins and other debris. Finally, B and T cells are produced in bone marrow and it is that site of B cell maturation.
If we were to walk away from this discussion remembering only one thing, I hope it would be that immune system function is dependent upon the ample supply of white blood cells and their ability to directly attack antigens (T cells) and produce antibodies that have the ability to neutralize foreign substances (B cells).
The Eat This, Not That Portion
Armed with this basic understanding of the immune system, we can now work on integrating specific nutrients that improve its ability to operate effectively and efficiently. Nutrients and foods of particular importance to the immune system include:
- Vitamin C – The single most important vitamin for the immune system, vitamin C is essential in the production of white blood cells and decreases susceptibility to infection. Dietary sources include: citrus fruits, broccoli, Brussels sprouts, dark leafy greens* and bell peppers.
- Vitamin A – Vitamin A enhances T cell activity and proliferation, contributes to B cell activation and antibody production, and works well with foods high in carotenoids and beta-carotene that are powerful antioxidants, free radical scavengers, and immune system enhancers. Dietary sources include: sweet potatoes, carrots, dark leafy greens*, butternut squash, and cantaloupe.
- Vitamin E – Vitamin E is a cofactor for vitamins C and A activity, acts as a powerful antioxidant and free radical scavenger to bolster immune function and plays an important role in T cell maturation in the thymus. Dietary sources include: sunflower seeds, almonds, spinach, dark leafy greens*, and papaya.
- Zinc – Zinc boosts the innate, non-specific immune response and helps promote wound healing. Dietary sources include: beef, lamb, sesame seeds, pumpkin seeds, oats and yogurt.
*’Dark leafy greens’ refers to kale, chard, mustard greens, dandelion greens and collards.
While this isn’t an exhaustive list, these are often considered the most fundamental nutrients that aid immunological function.
I probably don’t have to mention this, but looking at the foods listed above illustrates that a diet based upon fresh fruits and vegetables is probably the best way to provide your body and immune system the nutrients it needs to function at a high level. Also, hot foods like soups, stews and teas will go a long way in providing the mind, body and soul the warmth and comfort they needs during a long and arduous immunological battle against illness. Further, eating all the immune boosting foods in the world wont provide much help if we are not able to properly digest them. We must remember to thoroughly chew our food and eat in accordance with our body’s circadian cycle. Finally, a few minor lifestyle modifications will aid the immune system in fighting illness and hastening recovery when sick. If we eliminate excess stress, avoid highly allergenic foods, and abstain from the use of marijuana, alcohol and other illicit drugs we will be able to provide our body and immune system the proper environment to function at a high level.
I know, I know. What fun is life if we cant smoke ounces of pot and eat McDonalds all day long, right? Well, I am in no position to say what is or isn’t the best for your health one way or another, but maybe, just maybe maintaining a nutrient dense, plant based diet while sick or when highly susceptible to illness is the ticket to resounding health and wellness this holiday season. Worth a shot, right?