by Dan Gleason, DC

This article is a review and summary on an article from the journal BMJ Nutrition, Prevention & Health (https://nutrition.bmj.com/content/3/1/74).

The immune system protects humans from bacteria, viruses, fungi and parasites. To deal with these threats, the immune system has evolved to include specialized cell types, communicating molecules and functional responses. The immune system carries out continuous surveillance, then increases its activity when invaders threaten. Experimental research and studies of people with deficiencies has demonstrated that several vitamins (A, B6, B12, folate, C, D and E) and trace elements (zinc, copper, selenium, iron) have key roles in supporting the human immune system and reducing risk of infections. Human trials suggest that vitamins C, D and E, along with zinc and selenium intake is required to optimally support the immune system. These needs may be difficult to meet by diet alone, and in part to the typical American diet. Supplementation is often required to achieve optimal levels of these nutrients.

The intestinal microbiota plays a role in educating and regulating the immune system. Gut dysbiosis is a feature of many infectious diseases and has been described in COVID-19 literature. There is evidence that improving the gut microbiota with probiotic bacteria, particularly some lactobacilli and bifidobacteria, along with fiber and fermented foods, can modify the immune response and protect against infections, including in the respiratory tract. Gut microbes also help control inflammatory responses.

Severe lung infections can lead to acute respiratory distress syndrome (ARDS), characterized by excessive inflammation, often called the “cytokine storm.” This is seen in severe cases of COVID-19. There is evidence from ARDS in other settings that the cytokine storm can be controlled by omega-3 fatty acids EPA and DHA.

Aging is associated with a gradual loss of immune competence, a process called immunosenescence, via a decrease in production of immune cells from bone marrow. The thymus also shrinks, decreasing the output of naive T lymphocytes, resulting in reduced capacity to respond to new antigens. Older people, therefore, have increased susceptibility to infections, including respiratory tract infections, and poorer responses to vaccination, in general.

Obesity can also be associated with a loss of immune competence and reduced antibody production. Compared with non-obese individuals, obese individuals have increased susceptibility to a range of bacterial, viral and fungal infections and poorer responses to vaccination. For example, a French study found that 85.7% of obese individuals infected with SARS-CoV-2 required mechanical ventilation, compared with 47.1% of non-obese individuals. As Americans have high incidence of obesity, it is no surprise to see high rates of COVID-19 in the U.S.

Certainly, social distancing, appropriate use of masks, quarantines and vaccines will help deal with COVID-19; however, improving immune function is a powerful way to avoid or mitigate the serious effects of this pandemic virus as well as a way to get better results from vaccination and reduce the risk of side effects. Each person has unique nutrient requirements, so it is best to work with a functional medicine practitioner who uses testing to provide an individual program of diet and supplementation.

Dr. Dan Gleason is the owner of The Gleason Center located at 19084 North Fruitport Road in Spring Lake. For more info: go to TheGleasonCenter.com or call 616-846-5410.