The Importance of Strengthening the Immune System

With the start of the cold and flu season, the topic of immune-boosting has gained popularity.

The immune system does a great job defending your body against disease caused by harmful microorganisms and is even important in delaying the onset of cancer. Sometimes the immune system fails and a pathogen (e.g. viruses, bacteria, parasites, worms, fungi) successfully invades and makes you sick. Even when an infection occurs, the robustness of your immune system’s response can help shorten the length of the illness. For example, in the case of a mild infection caused by SARS-CoV-2 (the virus causing COVID-19), a strong immune system is generally able to clear the virus. However, in some people, a dysfunctional immune response occurs and a “cytokine storm” causes widespread lung inflammation and can lead to organ failure and death.

There are a number of individual and immune-related factors that can render some people more or less susceptible to damage from pathogens. In most cases, these factors are both controllable (e.g. diet), and uncontrollable (e.g. age). As a naturopathic doctor, I believe promoting the maintenance of a resilient immune system is a central component to optimizing health and well-being.

What Factors Affect Immunity?

Age

As we age, the capability of our immune system to respond to pathogens becomes reduced, which in turn leads to a greater incidence of infections and cancer. This is why the elderly are more likely to contract and die from infectious diseases. It is hypothesized that this is due to a decreased number of immune cells being produced by the body. Malnutrition leading to deficiencies in essential vitamins and minerals caused by a diet that is limited in substance and variety may also play a role.

Comorbidities

Comorbidities are medical conditions that co-occur with another. Metabolic syndrome, obesity, and type 2 diabetes are common conditions that can negatively affect immunity. Metabolic syndrome is characterized by a combination of three of the following components: central obesity, elevated blood glucose, elevated triglycerides, elevated blood pressure, and low HDL-cholesterol. Together with obesity, these conditions result in a loss of functioning immune tissue and result in an impaired immune response. In Type 2 Diabetes, there is abnormal insulin function, which leads to dysfunctional immune responses. Both the innate and adaptive parts of the immune system are weakened, making patients with this disease more susceptible to infection.

Diet

It is intrinsically difficult to study the effect of dietary intake of vitamins and minerals on the overall immune response. However, scientists have long recognized that those who live in poverty and are malnourished are more vulnerable to infectious disease. There are certain foods that contain natural antimicrobial compounds that may be helpful in warding off the incidence of infections. For example, garlic and onions contain allicin—a molecule that has been shown to inhibit the proliferation of bacteria and fungi. Alcohol consumption in high doses can directly suppress a wide range of immune responses, and alcohol abuse is associated with an increased incidence of a number of infectious diseases, especially of the lungs. Even a single occasion of moderate-to-heavy drinking results in an altered innate immune response. Moderate alcohol consumption is defined as one drink per day for women and two drinks per day for men.

Stress

Higher subjective levels of psychological stress are associated with greater incidence of infections and more symptomatic infections. Physical stress can also take a toll on the function of the immune system. For example, the risk of developing respiratory infections was shown to increase during periods of intense training and competition in competitive endurance athletes. On the other hand, moderate exercise appears to enhance the immune system and lower the risk of infections.

Sleep

Individuals getting less than seven hours of sleep at night are three times more likely to become infected by the common cold. A study of over 50,000 women found that those sleeping five hours or less were 70% more likely to develop pneumonia. A study looking at response to flu vaccines found that not getting enough sleep in the week before you get your flu shot resulted in a production of less than 50% of the normal antibody response. See below for more information on vaccine and antibodies.

What Else Can I Take To Help Improve My Immunity?

There are many products on the market that are advertised as immunity-boosters. Some of the most popular ones are echinacea, probiotics, vitamin C, vitamin D, and zinc. Depending on your current health conditions, past medical history, current medications, the safety profile of the supplement or herb, and what your goals are (e.g. preventing infections or shortening the course of an infection), there may be benefits from choosing one supplement or herbal preparation over another. I always recommend starting a supplement or herbal preparation with the guidance of a regulated health professional, preferably a naturopathic doctor.

A Note on Autoimmunity

This ability to distinguish between healthy tissues of the body (“self”) and pathogens, is a unique and crucial component of the immune system. Autoimmunity or autoimmune disease is what happens when this goes awry. In this situation, the immune system loses the ability to distinguish pathogens from “self” and mounts an immune response against healthy cells and tissues within the body. Autoimmunity is responsible for several diseases like rheumatoid arthritis, autoimmune thyroiditis, celiac disease, and multiple sclerosis, for example.

Like with many aspects of health, there is often no one direct “cause” for developing autoimmunity, but it may be due to a number of factors including, but not limited to, a decreased ability of the immune system to clear infections, the person’s sex (women tend to experience more autoimmune disease possibly due to their ability to mount a larger inflammatory response when the immune system is triggered, as well as experiencing physiologic changes when becoming pregnant), exposure to some infectious diseases and parasites, cigarette smoking, chemical agents, and genetics.

As you can imagine, bolstering one’s immune response in the presence of an autoimmune disease can exacerbate an existing condition. In these cases, the goal instead is to regulate the over-active immune response and manage excess inflammation within the body. This is why most individuals with autoimmune disease are treated with anti-inflammatory and/or immunosuppressive drugs (e.g. corticosteroids).

If you want to know more about the immune system and what you can do specifically to optimize your health and immunity, contact us to book an appointment with one of our experienced naturopaths in downtown Toronto.

References:

1. The trinity of COVID-19: immunity, inflammation and intervention. Nat Rev Immunol. 2020 Apr 28: 1–12.
2. Impact of Obesity and Metabolic Syndrome on Immunity. Adv Nutr. 2016 Jan; 7(1): 66–75.
3. Type 2 Diabetes and its Impact on the Immune System. Curr Diabetes Rev. 2020 May; 16(5): 442–449.
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5. =Moderate alcohol consumption and the immune system: a review. Br J Nutr. 2007 Oct;98 Suppl 1:S111-5.
6. Alcohol’s Effects on Lung Health and Immunity. Alcohol Res. 2015; 37(2): 199–208.
7. A recent perspective on alcohol, immunity and host defense. Alcohol Clin Exp Res. 2009 Feb;33(2):220-32.
8. Psychological Stress and Susceptibility to the Common Cold. N Engl J Med 1991; 325:606-612.
9. The compelling link between physical activity and the body’s defense system. J Sport Health Sci. 2019 May; 8(3): 201–217.
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12. Effect of sleep deprivation on response to immunization. JAMA. 2002 Sep 25;288(12):1471-2.