During this time when the media is consumed in chatter around how to best prevent the spread of Coronavirus, we wanted to share some research-backed information about what you can do to protect yourself. Without a vaccine or effective antivirals, your best chance at combating COVID-19 is your current health. And while we often defer to hand sanitizer, mega-doses of vitamin C, and the latest so-called “superfoods,” there is a more tried and tested way to strengthen your immune system. In this article, we’ll explore a few proven ways to stay healthy by making small tweaks to what you eat.
Go With Your Gut
We recently came across a landmark 2015 study conducted by a team in Sapienza Univeristy’s Department of Internal Medicine and Medical Specialties. It tore up the rulebook on how the body’s command center communicates with the immune system. For the longest time, scientists believed that the brain can only receive input and send back output when the central nervous system acts like a telephone operator and connects the caller to the correct recipient’s line. While this may well still be the case for the cardiovascular, musculoskeletal, and the body’s other major systems, we know now from the researchers who published their findings in the Annals of Gastroenterology, that the brain can bypass the central nervous switchboard. When necessary, a two-way conversation takes place via microbiota and receptor cells in the gut that are tied into the enteric nervous and immune systems.1
This revelation is part of the emerging body of evidence that suggests 70 percent of immune system function resides in the gut, making so-called “gut health” even more crucial when it comes to fighting off viruses, bacterial infections, and the other invaders that our bodies are bombarded with than was first thought. Yes, you could take a probiotic supplement to help with this. But given how many options there are on the market (thousands, with more appearing on physical and digital shelves all the time) and the fact that it’s hard to get a handle on your gut’s individualized needs, you’re better off investing in certain foods that have a broader spectrum of both probiotic and prebiotic properties. Fruit and vegetables are a good place to start because of their high fiber content, which is essential to optimal digestive health. Also give sprouted grains a try for the same reason, and because they contain more micronutrients like manganese, selenium, and copper than regular bread.
Then start introducing fermented foods to aid in digestion and boost immunity. There are plenty of options here, from two kinds of cabbage – spicy kimchi and that old German favorite sauerkraut – to Greek yogurt to pickles (the Bubbies brand kind, not cheap ones you’d put on a hot dog at a ball game). A little daunted by all of these options? Then grab a bottle of kombucha, which has become so popular of late that you can almost certainly find a flavor you like.
Z is for Zinc
Ask 100 people to name the main micronutrient involved in immune function and 99 would probably say, “Vitamin C.” This is partly grounded in fact, as this vitamin does indeed play an important role in the cellular response to the presence of viruses and bacteria.
While it is important to get 100 percent of your vitamin C RDA, taking excess amounts will be excreted by your body once they go past usable levels, so tipping fizzy packets into your water several times a day is likely accomplishing nothing. Instead, direct your attention to stacking another essential micronutrient on top of your vitamin C intake. Zinc is a mineral that’s critical to immune function, as shown by a seminal study published in Molecular Medicine in June 2008.2 Yes, those same mega-dose supplements that sell out at this time of year do contain it, but they also often include artificial colors and flavors that might be bad for you.
So instead, take advantage of prime citrus fruit season while it lasts and load up on oranges (Cara Cara, blood, and tangelo varieties are all tasty alternatives to the go-to staple navel), grapefruit, and clementines, which also happen to make perfect, easy-to-peel school snacks if you happen to have kids. And, of course, an orange a day will also give you everything you need on the vitamin C front, as well as packing a potassium and vitamin A punch.
Blackcurrant is another underrated rich source of zinc. Widely consumed across Europe, it’s still a niche product here in the US, but if you can’t find the berry itself (as you will be able to growing wild and at farmer’s markets in the Pacific Northwest, Michigan, and other areas where berries are prevalent), try it in unsweetened juice form. Elderberry has a very similar chemical profile, but while it is easier to find, it’s much more expensive and has a bitter taste.
Pack in More Protein
We’ve written extensively about how your body breaks down protein into amino acids that are used to heal the microtears caused by exercise, rebuild muscle fibers, and even expand them (hypertrophy). While this is vital for exercise recovery, protein also plays a largely unheralded role in immunity. When your body’s digestive enzymes go to work on protein, they not only send amino acids into your bloodstream, but also antibodies. A research duo at Walter and Eliza Hall Institute found that the protein myb enables immune cells to regulate the strength of their response, depending on the threat level.3
While you will eventually hit a protein intake point where a law of diminishing returns comes into effect, it’s safe to say that if you’re currently training and/or competing hard while your exposure to viruses is elevated, you could probably do with consuming a little extra protein. So load up on fish, dairy, and lean meats. Your immune system will thank you.
- 70 percent of immune system function resides in the gut.
- Eat plenty of fruits and vegetables to increase your fiber intake to optimize digestive health.
- Try including sprouted grains for their fiber content, but also for their manganese, selenium, and copper.
- Eat fermented foods like kimchi, sauerkraut, Greek Yogurt, pickles, and kombucha to aid in digestion.
- Oranges, grapefruits, and clementines offer high sources of Vitamin C and Zinc.
- Blackcurrant is our favorite underrated rich source of Zinc.
- Protein plays a large role in immunity, so focus on maintaining fish, dairy, lean meats, and high quality protein powder in your diet.
1 – Marilia Carabotti et al, “The Gut-Brain Axis: Interactions Between Enteric Microbiota, Central, and Enteric Nervous Systems,” Annals of Gastroenterelogy, 2015, available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/.
2 – Ananda S Prasad, “Zinc in Human Health: Effect of Zinc on Immune Cells,” Molecular Medicine, June 2008, available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277319/.
3 – Sheila Diaz et al, “Effector Regulatory T Cell Differentiation and Immune Homeostasis Depend on the Transcription Factor Myb. Immunity, 2017, available online at https://www.ncbi.nlm.nih.gov/pubmed/28099866.