Immune modulation—having an aggressive immune (defense) system, available to meet invading pathogens and destroy foreign cells—came into vogue, when Covoid-19 first surfaced, as a recognized disease. Prior to the SARS-2 infection, immune modulator agents—such as various types of immunotherapy—were referenced relative to cancer treatments.
One related factor to both cancer and Covid-19 is the unique role that cytokines—proteins made by white blood cells—play in the human body’s normal immune response. Covid-19 causes a “cytokine storm,”—a situation where, “viral replication triggers an abnormally strong release of cytokines and other immune-related stimuli, resulting in hyper-inflammation.”
Inflammation and oxidative stress are essential to the normal functioning of the human body. Free radical oxidative stress can have a protective effect against invading microorganisms. However, chronically elevated oxidative stress—defined in relation to excessive reactive oxygen and nitrogen species–is seen in longer duration viral diseases like HIV and Epstein-Barr.
According to Strengthening the Immune System and Reducing Inflammation and Oxidative Stress Through Diet and Nutrition: Considerations During the Covid-19 Crisis, which appears in the July 2020 online issue of Nutrients, “an optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay.”
For instance, a low protein intake—below the basic recommended 0.8 grams per kilogram of body weight–has been shown to increase risk to infection. The study authors—from Luxembourg Institute of Health, First Moscow Medical University, and California Polytechnic State University—comment that, “the low pool of available proteins also results in a decreased amount of functional active immunoglobulins and gut-associated lymphoid tissue (GALT), which play a role in gut-mucosal defense against infection.”
Further stating that high quality proteins—such as eggs, fish, lean meat (poultry), and whey proteins–are an essential component of an anti-inflammatory diet, as are plant-derived proteins–like pea isolate protein.
The amino acid glutamine is needed to support genes of the immune system–with glutamine providing energy to, “macrophages, neutrophils, and lymphocytes, (which are) needed for pathogen-identification through the proliferation of immune cells and the repair of tissues.”
Fatty acids (FA) can alter the immune response. Note the researchers, “(essential) omega-3 FAs appear to have the most potent anti-inflammatory capability, though not all omega-3 FAs are anti-inflammatory. Trans-fatty acids derived from processed foods, such as fries and chips, are pro-inflammatory.
The omega-3 FA alpha linolenic acid (ALA) is obtained from various plant sources, while the two other Omega 3’s, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in fish and seafood sources–salmon, mackerel, and tuna.
The essential omega-6 FAs, such as arachidonic acid–found in certain vegetable oils and processed, baked goods–are primarily pro-inflammatory, and can hamper the omega-3 metabolism, when a ratio of omega-6 to omega-3 exceeds 10:1 versus a healthy ratio of 1:1 to 4:1.
From a gut health perspective, prebiotic (food for healthy GI bacteria) fiber is critical to offset a pro-inflammatory-type diet. As the researchers point out, “while the intake of 25 grams and 38 grams of fiber for women and men, respectively, is recommended, true intake is generally lower (around 15–20 g/d), at least in Westernized countries.”
An advantage of whole-grain intake is to create a more favorable gut microbiome (organisms in GI tract) composition, which lowers both gut and systemic inflammation, and even small increases of only 5 grams of additional fiber per day can be beneficial, comment the researchers.
Let’s add to the list fermented foods, such a yogurt and kefir, to support the GI system—increasing favorable short chain fatty acids and healthy GI bacteria. Bifidobacterium, lactobacillus, faecalibacterium, ruminococus, and prevotella have been associated with lower systemic inflammation.
Micronutrients that support immune function include:
Vitamin A supports a healthy mucus layer in the respiratory tract and intestine; vitamin D from fish, eggs, fortified milk and mushrooms supports T-cell function; vitamin E is important for coordination of the adaptive and innate immune response; vitamin C is a “classical” antioxidant that has been shown to stimulate the migration of neutrophils to the infection site, while B vitamins are involved in numerous energy-related processes.
The mineral zinc serves as a cofactor in over 200 enzymes involved with antioxidant defense. Iron helps fight off infection by increasing T-lymphocyte immune cell maturity. Copper is involved in innate immune responses to bacterial infection, while selenium has a primary role as an antioxidant to “quench” the anti-inflammatory reactive oxygen species effect.
Other nutrients in the immune arsenal are polyphenols found in fruits and vegetables, and carotenoids–lutein, zeaxanthin, and carotene, which is a precursor to vitamin A.
It all adds up to consuming a balanced, modified Mediterranean-type diet with the addition of a comprehensive multi-vitamin/mineral immune-based formula.