Lifestyle Modifications for a Stronger Immune System

People with chronic diseases such as obesity, hypertension, and diabetes have been shown to be at greater risk for COVID-19-related illness and death. The functional medicine approach to COVID-19 involves strengthening the immune system to reduce the risk of viral infection through an assortment of lifestyle interventions from diet to relationships.

Research shows that eating a plant-based diet rich in phytonutrients, vitamins, antioxidants, and fiber can reduce viral infection and severity by balancing inflammatory pathways. This is achieved by reducing inflammatory foods, such as added sugars, salts, and trans fats or excessive saturated fats, and increasing foods with anti-inflammatory effects, such as fruits, vegetables, and legumes.

Food and nutrition may further reduce viral susceptibility and severity by reducing oxidative stress. Viral infection begins with an abundance of oxidative stress, known as a “cytokine storm,” which produces damaging free radicals in the body. Cooking at lower temperatures and boiling and steaming food creates fewer oxidative compounds than grilling, frying, and broiling. Eating foods high in antioxidants, such as spices and herbs, nuts and seeds, and vegetables, may be helpful for reducing oxidative injury.

Harmonizing the gut microbiome also improves immune function. The majority of immune system activity occurs in the gastrointestinal tract, so gut health is critical. High-fiber diets can directly modulate immune reactivity. Fermented foods such as yogurt, kefir, kimchi, miso, and sauerkraut may help with immune response and reduce incidence and duration of respiratory infections. Research has shown that probiotic microorganisms within the Lactobacillus and Bifidobacterium species provide numerous benefits to immunity.

A wide variety of plant compounds is key for immunity and a healthy gut microbiome. Polyphenol compounds found ubiquitously in plant foods are known to be especially powerful immune-regulating foods. These include apples, onions, grapes, green tea, and turmeric. Research has shown eating a healthy diet with a diversity of fruits and vegetables results in lower DNA oxidation than eating a less diverse group of fruits and vegetables. Experts advise eating 9-13 servings per day of a wide variety of fruits and vegetables, including fermented vegetables and other probiotic-rich foods, and consuming 28-35 grams daily of dietary fiber from whole foods.

Chronic stress is known to suppress the immune system, resulting in a higher likelihood of illness. Many people live with a baseline of stress in daily life that is chronically elevated, so functional medicine practitioners encourage the use of assessments to monitor stress level, in some cases recommending biofeedback devices, such as heart rate variability monitors, to detect heightened release of inflammatory markers. In addition, stress management techniques such as yoga, meditation, Tai Chi, and breath exercises have been shown to benefit immune regulation and reduce susceptibility to infection.

Research has shown that sleep serves a restorative and regulatory purpose that strongly influences immune function. Even one night of reduced sleep disrupts immune system activity. Experts advise aiming for seven to eight hours of quality sleep each night. A good sleep routine includes setting a reminder to go to bed at a regular time each night, turning off screens, and having a cool, quiet, dark sleep environment.

Exercise improves immune function in a number of different ways. Research has shown that even a single instance of physical activity can stimulate immune function, but regular exercise confers optimal immune system benefits. Stretching, walking, stair climbing, and yoga require no equipment and can be done safely at home in compliance with social distancing requirements. Exercising outside in nature has been shown to improve immune recovery, decrease stress, and increase relaxation.

Social relationships are another key determinant of immune health. Research has shown that a sense of supportive connection through ones’ social network improves markers of immune health. Functional medicine practitioners recommend reducing non-supportive interactions and seeking out positive, affirming relationships.