Protect Our Immune System During This Difficult Time – Part III
Part III: Other considerations
Probiotics & Prebiotics
You may think your body is 100% yours. But you are wrong. According to the American Academy of Microbiology, an adult human body has 37.2 trillion human cells – that sounds like a lot, but the human microbiome has 100 trillion bacterial cells . So simply put, you are more like an ecosystem than simply yourself. Mind-boggling, right?
Granted, some of these bacteria can be harmful, but there are many that live in our GI (gastrointestinal) tract that are beneficial. For example, some bacteria help complete the digestion of certain food residues and produce certain vitamins (for example, Vitamin K), and some produce energy for our metabolic use. Research has found that a healthy GI flora protects our GI tract integrity and plays an anti-inflammatory role in our immune system . So, is your answer to consume more yogurt? Certainly, probiotics and fermented products such as yogurt, kefir, kombucha, tempeh, miso, kimchi, and sauerkraut all contain healthy microbes that can help boost our healthy GI flora population, but there is more than that. Incorporating foods with prebiotics, such as those rich in dietary fiber, promote the growth of healthy microbes and inhibit the harmful ones. There is no reason to rush to buy prebiotic products or fiber supplements. They are abundant in whole foods such as fruits, vegetables, legumes, and grains.
Spice Up your Immune Diet
If you are a foodie, you must have heard of the culinary “holy trinity”, or the mirepoix. Mirepoix is the French word to describe the light cooking of onion, celery, and carrots to provide flavor to dishes. Using aromatics to create a base flavor is not unique to French cuisine; in fact, almost every food culture has its own signature mirepoix. The version of Chinese mirepoix changes when you move from region to region in the country, but two household staples can always be found: garlic and ginger. Growing up in China, I sauté almost everything with minced garlic and ginger. I also use ginger in soups and smoothies. The other thing I sometimes add to my smoothies and stews is turmeric. It turns out these spices – garlic , ginger , and turmeric , all boost our immune system by either being antioxidant or having anti-inflammatory functions. Herbs are great additions too. Cilantro, green onions, parsley – use them generously and creatively to not just boost the flavor, but your health as well.
Other Nutrient Considerations
Two B vitamins, B6 and folic acid, play critical roles in cell production and maintenance. It is therefore not a surprise that they are beneficial for our immune system as well. Experiments on animals have shown severe deficiency impairs immunity, however, similar deficiency hasn’t been assessed on human immune functions . Nevertheless, both nutrients are essential for a healthy body, and the National Academy of Medicine has established corresponding Recommended Dietary Allowance (RDA). The good news is, a lot of the foods we’ve already recommended, such as vegetables, whole grains, or some beans (especially chickpeas and soybeans), are very high in both B6 and folic acid. If you don’t have a restricted diet, meat products are naturally high in B6 as well.
One cautionary note is, overconsumption of almost any nutrient can be harmful. The National Academy of Medicine therefore established Tolerable Upper Intake Levels (ULs) for nutrients. But don’t panic. It is almost impossible that you can eat your way to exceed these limits if you choose a balanced, moderate, and varied whole-food diet. If you are not heavily subsidizing on supplement pills, chewing on steel pipes, or chomping on carrots like a bunny, the chance is that you are just fine. If you have a medical condition that makes you more deficient in certain nutrients, make sure you talk to your physician or a registered dietitian.
It is more important than ever that we practice healthy habits in the face of COVID-19. That means, not only eating the foods that boost our immune system, but also eating healthy in general. We like what Michael Pollan said in his book, In Defense of Food: Eat food, not too much, mostly plants – by the way, if you are bored at home (and right now, most of us are), buy this book and read it. You can thank me later.
In addition to eating, exercise also helps our immune system. So don’t be couch potatoes and start moving. We are lucky our gym (Thank you Irontribe!) allowed us to borrow some weights. We are finding creative ways to use all things we can find to stay active. Depending on where you live, you may still be able to go outdoors to have a run. If you do, stay away from other runners. Try to hit the road at a less busy hour or try a less busy neighborhood to run. Over exercising, however, can compromise your immune system, but so far, we haven’t run into that problem – no pun intended.
Have enough sleep. Drink moderately. Stop smoking. If you are watching a lot of Netflix these days, don’t binge until late at night. Try to find productive things to occupy yourself with: read a book, learn a skill through online lessons, start cooking, start a garden, talk to your loved ones, exercise together with your loved ones. I hope we will be over with this soon and emerge stronger and healthier.
 Thompson, J., Manore, M., & Vaughan, L. (2019). Science of Nutrition, 5th edition. Pearson Higher Ed.
 Mashhadi, N. S., Ghiasvand, R., Askari, G., Hariri, M., Darvishi, L., & Mofid, M. R. (2013). Anti-oxidative and anti-inflammatory effects of ginger in health and physical activity: review of current evidence. International journal of preventive medicine, 4(Suppl 1), S36–S42.
 Arreola, R., Quintero-Fabián, S., López-Roa, R. I., Flores-Gutiérrez, E. O., Reyes-Grajeda, J. P., Carrera-Quintanar, L., & Ortuño-Sahagún, D. (2015). Immunomodulation and anti-inflammatory effects of garlic compounds. Journal of immunology research, 2015, 401630. https://doi.org/10.1155/2015/401630
 Jagetia, G. C., & Aggarwal, B. B. (2007). “Spicing up” of the immune system by curcumin. Journal of clinical immunology, 27(1), 19-35.