Hi there! It’s Amy here. In this crazy time of covid, over-sanitization of everything we touch, election stress, homeschooling while working from home, all piled up on top of the normal cold and flu season — our immune systems are taking a hit. But the good news is that there are dietary and lifestyle practices we can implement to boost our immune systems. For this blog post I have invited Cassidy, a Dietetic intern, to help compile some research on the best ways to support the immune system.

---

What is the Immune System? 

Our immune system is our body’s way of protecting us against pathogens such as bacteria, toxins, and viruses. It consists of two networks, the innate and adaptive immune systems which work together to fight off those foreign invaders. 

How does it work? 

The innate immune system is the fast-acting, first line of defense against harmful microbes. It includes the skin, immune defense cells, and proteins. 1

If a pathogen passes through the skin’s barrier, it is confronted with defense cells that release substances triggering inflammation which in turn, can lead to a fever. 

Our adaptive immune system works slower than its counterpart but precisely targets specific germs. This unit consists of B and T cells which identify and attack pathogens, as well as antibodies which prevent us from getting a disease again, hence the term “immunity.” 2

The adaptive immune system has the unique characteristic of being able to “remember” foreign invaders and therefore, will have a much quicker response if it enters the body again. 

Are you getting the proper nutrients? 

If you’re wanting to maintain a healthy immune system, it is important to ensure a well-balanced diet filled with fruits and vegetables for adequate nutrition. 

Diets containing a variety of fruits and vegetables provide a plethora of nutrients to the body, many of these containing antioxidant properties. Many of these include: 

Beta-carotene- the pigment that gives fruits and vegetables an orange color. This is commonly found in sweet potatoes, carrots, oranges, butternut squash, and more. This nutrient plays a possible role in preventing cancer. 3
These are fat-soluble, so the nutrients are better absorbed when paired with a fat, like olive oil!

Vitamin C is an antioxidant that contributes to the functions of both the innate and adaptive immune systems. As humans, we cannot make this nutrient in our body so it must be obtained through our diet. It is commonly found in red bell peppers, broccoli, spinach, and other leafy green vegetables. 

Vitamin D has been shown to reduce the risk of possible infections and deficiency in this nutrient is present in those with autoimmune diseases.7 
The best source of vitamin D is daily strategic sun exposure! To increase your vitamin D consumption, try implementing certain fish, such as salmon and trout. Whole milk, egg yolks, and cod liver oil have also been found to contain high levels of this vitamin. 

Vitamin E is a fat-soluble antioxidant defending against free radicals. Deficiency in this vitamin is linked to Cystic Fibrosis (CF) and Crohn’s Disease.13
Foods containing vitamin E include nuts, salmon, and avocado.

While these vitamins and nutrients are extremely beneficial, we must also be aware of what can hinder their effectiveness. The western diet is abundant in fast food which contains unnecessary sugars, sodium, saturated and trans fats. Excess intake of added sugar and sodium has been shown to contribute to the depletion of nutrient stores, as well as inflammation.

Your Gut’s Role in Immune Function 

The gastrointestinal system, commonly referred to as the “gut,” comprises digestive organs such as the esophagus, stomach, pancreas, gallbladder, and intestines. Besides promoting smooth digestion, the GI system aids immune function. 70-80% of immune cells are found in the gut!10 Here we find gut-associated lymphoid tissue (GALT), which serve as our first line of defense against infection.11 

At a microscopic level, the GI system houses the microbiome, home to trillions of bacteria and fungi that coexist together. This composition of microorganisms varies with each individual, dependent upon his or her lifestyle, dietary habits, body mass index (BMI), antibiotic intake, and more.12

This system encompasses many functions of the body, yet does not receive much recognition unless alterations are present. The slightest imbalance in gut microbiota can lead to a plethora of issues including constipation, bloating, heartburn, and autoimmune disorders.  

If you struggle with GI discomfort, try implementing a probiotic into your diet. Probiotics are found in fermented foods such as sauerkraut, kimchi, kombucha, as well as some yogurts that explicitly state that they contain live cultures. You can also find probiotics in supplement form. You can find some of Amy’s favorites in her online dispensary.

Elderberry 

Another supplement that can be beneficial to possibly preventing infection and shortening the duration of flu-like symptoms, is elderberry.4 Derived from the Sambucus tree family, elderberry is sold in the form of gummies, syrup, and lozenges at nearly any local supermarket or health store. Look for one without added sugar. 

Are you getting enough sleep?

Besides needing sleep to recover from the craziness of everyday life, sleep is crucial to your immune health!

Our bodies function like clocks; we like to go to bed at the same time and wake up at the same time. This unique biological process is known as the circadian rhythm. 

When this rhythm is interrupted and we are sleep deprived, we are then left more vulnerable and susceptible to disease. This is why many college students fall sick after taking their finals- more time spent studying and less time sleeping leads to a depressed state of immunity.5

What about stress?

Our lives are naturally filled with stressors, but 2020 brought it to a new level. From worrying about our jobs, health, our children’s health, and so many more, life is anything but easy. 

However, all this stress and worry can manifest physically, leading to immune system depression and even sickness! Our bodies produce a hormone in response to stress, called cortisol. This hormone is responsible for a variety of good things, such as keeping blood pressure at normal levels and reducing inflammation, but chronic high levels can be detrimental. 

If we feel stressed all the time, cortisol levels remain elevated, leading to a compromised immune system. This excess cortisol has been linked to ailments such as irritable bowel syndrome, rheumatoid arthritis, multiple sclerosis, anxiety, depression, and more.6

Fortunately, there are many ways to alleviate the stress of everyday life. Simple tasks such as going on walks, taking baths, prayer & meditation, and reading a book, are ways to find peace and be still in the middle of a crazy week. 

As mentioned earlier, keeping your diet in check by including nutrient-dense foods can have positive effects on your health. Sleep, nutrition, and stress management are the most important factors in maintaining a well-balanced immune system.

Cassidy is a Dietetic student at Texas Woman’s University. She is also a personal trainer who enjoys all things fitness and wellness. When she is not working or studying, Cassidy loves going to church at Mercy Culture and taking long walks outside.

References

1. CDC. Test for Past Infection. Cdc.gov. 2020 Sep 18 [accessed 2020 Oct 2]. https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html
2. InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. The innate and adaptive immune systems. [Updated 2020 Jul 30].Available from: https://www.ncbi.nlm.nih.gov/books/NBK279396/
3. Hughes DA. Effects of carotenoids on human immune function. Proc Nutr Soc. 1999 Aug;58(3):713-8. doi: 10.1017/s0029665199000932. PMID: 10604207.
4. Complementary and alternative medicine – Penn state Hershey medical center – elderberry – Penn state Hershey medical center. Adam.com. [accessed 2020 Oct 2]. 
5. Besedovsky L, Lange T, Born J. Sleep and immune function. Pflugers Arch. 2012;463(1):121-137. doi:10.1007/s00424-011-1044-0
6. Morey, J. N., Boggero, I. A., Scott, A. B., & Segerstrom, S. C. (2015). Current Directions in Stress and Human Immune Function. Current opinion in psychology, 5, 13–17. https://doi.org/10.1016/j.copsyc.2015.03.007
7. Aranow C. Vitamin D and the immune system. J Investig Med. 2011;59(6):881-886. doi:10.2310/JIM.0b013e31821b8755
8. Manzel, A., Muller, D. N., Hafler, D. A., Erdman, S. E., Linker, R. A., & Kleinewietfeld, M. (2014). Role of “Western diet” in inflammatory autoimmune diseases. Current allergy and asthma reports, 14(1), 404. https://doi.org/10.1007/s11882-013-0404-6
9. DiNicolantonio, J. J., & Berger, A. (2016). Added sugars drive nutrient and energy deficit in obesity: a new paradigm. Open heart, 3(2), e000469. https://doi.org/10.1136/openhrt-2016-000469
10. Furness, J. B., Kunze, W. A., & Clerc, N. (1999, November 1). Download Citations: Future Science. Retrieved October 29, 2020, from https://journals.physiology.org/action/showCitFormats?doi=10.1152%2Fajpgi.1999.277.5.G922
11. Ruth, M.R., Field, C.J. The immune modifying effects of amino acids on gut-associated lymphoid tissue. J Animal Sci Biotechnol 4, 27 (2013). https://doi.org/10.1186/2049-1891-4-27
12. The Microbiome. (2020, May 01). Retrieved October 30, 2020, from https://www.hsph.harvard.edu/nutritionsource/microbiome/
13. Office of Dietary Supplements – Vitamin E. (n.d.). Retrieved October 30, 2020, from https://ods.od.nih.gov/factsheets/VitaminE-Consumer/