Foods to Fight COVID-19 – Eat and Live Healthfully

With the rapidly increasing number of COVID-19 cases and the potential seriousness of the illness, now more than ever is the time to focus on taking care of ourselves. Thanks to all the amazing scientists and medical teams working day and night, we have learned a lot about coronavirus, the immune system, and the points where they intersect. Our bodies are designed to protect against foreign invaders; and like any effective army, we have to make sure our immune system has the right tools and training to do its proper job.

So what can we do to buff up our immune system to offer the most protection?

First, start with following the CDC guidelines, as prevention is always the strongest line of defense.

Wear a mask.
Physical distance – at least 6 feet.
Avoid indoor gatherings outside those in your household.
Wash your hands.
Stay home this holiday season.

Frontload the Initial Immune Response

Additionally, we can use food to help frontload our initial immune response, which is prepared to rid our bodies of any invaders, including the novel SARS-CoV-2. Here are my top 11 foods, based on recent studies, to eat regularly and help enhance your immune system. Many of them are even some of our holiday favorites!

Mushrooms – Have been shown to increase secretory IgA antibodies, which are the prominent 1st-responder antibodies found in the mucosa layer, such as the nose, lungs, and gut lining. In one study, 1/3^rd cup of button mushrooms daily increased secretory IgA by 144% after 1 week. It appears to be the beta-glucan found in mushrooms that has the immunomodulatory effect. Be sure to eat the stems, too, because they contain 30% more beta-glucans than the caps.
Cranberries – Cranberry polyphenols enhance gamma-delta T cells, (γδ T cells), which also are part of the initial, rapid branch of the innate immune system, quick to respond to a foreign invader and notify the adaptive immune response of what’s coming. In a randomized, controlled study where people drank 15 oz cranberry juice daily or placebo for 10 weeks, those drinking cranberry juice were found to have 16% less cold and flu symptoms, 51% less GI distress, and 31% less missed days at school and work. This was associated with a 3.2-fold increase in gamma-delta T cells and a 172% increase in interferon secretion.
Blueberries, blackberries, pomegranates – The anthocyanins in these deeply colored fruits have been shown to activate Natural Killer (NK) cells, which target viral-infected and abnormal cells and eliminate them.
Garlic – The compound Allium sativum in garlic, has been shown to stimulate macrophages, lymphocytes, natural killer (NK) cells, dendritic cells, and eosinophils, which are all important early responders of the immune system. Garlic also helps regulate the immune system response by modulating cytokine secretion and immunoglobulin production, among other immune functions.
Fermented vegetables – When looking at countries that traditionally eat fermented vegetables such as sauerkraut, kimchi, and pickled vegetables, they show a significant decrease in mortality from COVID-19. For example, for each g/day increase in the average national consumption of fermented vegetables, the mortality risk for COVID-19 decreased by 35.4%.
Cruciferous vegetables – This includes the cabbage, broccoli, kale, cauliflower family of vegetables. These brassica vegetables, as they’re called, stimulate the master antioxidant response element (ARE), which serves as a gene transcription factor, activating multiple anti-inflammatory genes. Additionally, cruciferous vegetables are activated into compounds such as ITCs, DIM, and sulforaphane, which have natural antiviral and antibacterial activity.
Seaweed – Contains sulfated polysaccharides, which were found to bind the ACE-2 receptor and gum it up, thereby inhibiting COVID-19 from binding to it. It’s actually a similar mechanism as Remdesivir, an anti-viral used to treat COVID infection. Some examples include kelp and nori, often used in Japanese cuisines.
Soluble fiber – Found in foods like beans, chia seeds, oatmeal, barley, apples, citrus fruits, and berries. Soluble fiber is food for our healthy microbiome, increasing microbes like Lactobacillus, which have an anti-inflammatory and immune-activating function. Eating a variety of plant-based, fiber-rich foods is helpful to create a robust and diverse microbiome to offer maximum protection.

Reduce Inflammation and the Cytokine Response

While we want to have a robust initial immune response, we want to avoid the body from over-reacting with out-of-control immune cells, known as the “cytokine storm”. Eating and living an anti-inflammatory lifestyle might offer some protection. For example, excessive amounts of sugar have been shown to elevate CRP (C-reactive protein), a clinical marker of systemic inflammation. Another helpful factor for reducing general inflammation is reducing the amount of animal products eaten, as people on a whole-food, plant-based diet (WFPB) demonstrate lower CRP.

Enhance a Vaccine Response

Broccoli, Broccoli sprouts – With multiple vaccines showing promise against COVID-19, the hope is that we are able to generate a significant response against the virus. In one small study, people given broccoli sprouts for two days before receiving a nasal flu vaccine had 22 times more natural killer cells and fewer flu virus particles in their nose. The sulforaphanes in the broccoli sprouts appear to directly enhance the immune effect.

Putting it Together

This integrative approach – following the CDC-recommended precautions, practicing good hygiene, getting medical care when needed and the vaccine when available, eating foods to fight the virus, and taking care of ourselves might just be the best approach. This virus has shown us how sneaky it can be; it’s time we fight back.

References:

Investigations of Immunomodulatory Effects of White Button Mushroom Medicinal Properties Against Covid-19. Journal of Environment, Science, and Technology, 2020.
Immunomodulation and Anti-Inflammatory Effects of Garlic Compounds, Journal of Immunol Res. 2015.
Eating green veggies improves immune defenses, Science Daily, 2011.
Is diet partly responsible for differences in COVID-19 death rates between and within countries? BMC, May, 2020.
Association between consumption of fermented vegetables and COVID-19 mortality at a country level in Europe, MedRxIV, BMJ, 2020.
Consumption of cranberry polyphenols enhances human γδ-T cell proliferation and reduces the number of symptoms associated with colds and influenza: a randomized, placebo-controlled intervention study, Nutrition Journal, 2013.
Effect of Dietary Sugar Intake on Biomarkers of Subclinical Inflammation: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients, 2018
Effect of Broccoli Sprouts and Live Attenuated Influenza Virus on Peripheral Blood Natural Killer Cells: A Randomized, Double-Blind Study. PLoS One, 2016.
In cell studies, seaweed extract outperforms remdesivir in blocking the COVID-19 virus. Science Daily, July, 2020.
The COVID 19 novel coronavirus pandemic 2020: seaweeds to the rescue? Why does substantial, supporting research about the antiviral properties of seaweed polysaccharides seem to go unrecognized by the pharmaceutical community in these desperate times? Journal of Applied Phychology, 2020.
Anti‐Inflammatory Effects of a Vegan Diet Versus the American Heart Association–Recommended Diet in Coronary Artery Disease Trial, Journal of the American Heart Association, 2018.
Change in Plant-Based Diet Quality Is Associated with Changes in Plasma Adiposity-Associated Biomarker Concentrations in Women, The Journal of Nutrition, 2019.