Introduction
As the COVID-19 pandemic continues to remain a very relevant and detrimental phenomenon within American society, many may feel helpless or vulnerable to its spread. While we can work to control infection rates through vaccination, social distancing, and masks, little is known about effective treatments to treat the novel coronavirus. Rather than worrying about the many uncontrollable factors we face throughout this tumultuous time, we can empower ourselves with nutritional knowledge and work to increase immune strength through improved metabolic health.
The Most Vulnerable
One significant risk factor for chronic disease, and indirectly COVID-19, is overnutrition or inadequate nutritional status. Overnutrition leads to obesity, a chronic disease characterized by increased visceral, or abdominal, adipose tissue. Adipose tissue, commonly known as fat, is composed of adipocytes that multiply with overconsumption of macronutrients. Within this visceral adipose tissue are signaling molecules, called adipokines, that work to communicate between cells in the body. In individuals with an excessive amount of body fat, adipokines trigger metabolic disturbances and lead to secondary health conditions such as cardiovascular disease, hypertension, insulin resistance, and inflammation.
Some of the main chronic conditions associated with adverse COVID-19 outcomes include cardiovascular disease, obesity, type 2 diabetes, respiratory disease, and immune dysregulation. Elderly persons and those with underlying chronic conditions are most likely to be admitted to the hospital due to COVID-19 progression. Recent studies have highlighted the link between metabolic dysfunction and increased pathogenicity of the virus.
Linking Nutrient Intake and the Immune System
Adequate nutrition is incredibly important for geriatric patients, as the bioavailability of micronutrients and uptake of macronutrients is often lowered with increasing age. Insufficient micronutrient intake can lead to suppressed immune response, including dysregulation of immune signaling cells, or cytokines, and impaired antibody function. While it should not be touted as a cure, proper nutrition has been shown to support our metabolic processes and improve disease states. Micronutrients, such as vitamins and minerals, work to aid our cells in energy metabolism and biochemical interactions, leading to improved immune cell function.
We all know that consistently practicing healthy habits is easier said than done. The Harvard School of Public Health has created a guide, as shown in Figure A, to provide some tips and strategies that may help maintain a healthy lifestyle during these uncertain times of the COVID pandemic.
How I Can Improve My Diet to Support Immune Function
Navigating the many food products sold in grocery stores can be a daunting task for the average American. Many of these products may have misleading slogans such as ‘natural’, ‘organic’, and ‘low-fat’. A food that is low in fat may substitute healthy polyunsaturated fatty acids (PUFAs) with copious amounts of simple sugars. PUFAs help control inflammation and have been shown to have preventive effects on risk factors associated with COVID-19 such as cardiovascular disease, obesity, and type 2 diabetes. These healthy fats can be found in fish, as well as plant-based foods such as olive oil and walnuts.
Vitamin D is a fat-soluble and naturally-occurring micronutrient in our bodies that may have therapeutic effects on respiratory tract infections. We are better able to synthesize Vitamin D through time spent in the sun, in addition to consumption of dairy, egg yolks, and whole milk. No worries if you follow a vegan or plant-based diet, as many foods are fortified with this important vitamin.
Another fat-soluble micronutrient, Vitamin A, has been shown to aid the immune system by improving the cellular and humoral branches of the immune system. These branches are essential in fighting off pathogens and developing memory immune cells to recognize antigens from past infections. Some foods that are a great source of Vitamin A include bell peppers, eggs, and carrots.
Dysbiosis, an interruption in the bacterial population within the gastrointestinal tract, is caused by disease states or poor nutritional status. This interruption has been correlated with hyper-inflammation and the progression of COVID-19. The healthy flora in our GI-tract, also called probiotics, create a diverse gut microbiome that houses many immune cells. Probiotics can be consumed through fermented food products such as sauerkraut, apple cider vinegar, kimchi, and daily probiotic supplements.
Takeaway
COVID is most risky for those with pre-existing conditions, some of which can be prevented with proper nutrition. It is important that we begin to prioritize disease prevention practices alongside episodic care by introducing nutritional guidelines early on. Incorporating proper nutritional education within primary care can help to establish a preventive, food-approach foundation within our healthcare system and combat the rising number of casualties caused by chronic disease and any future pandemics.
Although proper nutrition helps to improve inflammatory responses and support the immune system, the pathophysiology of COVID-19 is still largely unknown and these interventions will not prevent infection or transmission to others. In a time of many unknowns, we may find solace in taking control of our dietary choices in order to optimize our individual health and wellness.
For more information on how to make your grocery trips healthy and affordable, visit KIN’s Tips & Tricks. In addition, don't forget to check out Harvard's Healthy Living Guide 2020-2021.
Additional Sources:
MCGUIRE, MICHELLE. NUTR. 2nd ed., CENGAGE LEARNING, 2016.