Immunity Post-COVID

There is no food or supplement capable of preventing or curing COVID-19. However, nutrition does play a role in bodily defenses against infection. We spoke with Stephanie Biggs, a Registered Dietitian, about thinking about immunity, and how nutrition Post-COVID will be affected.

• How is nutrition linked to immunity?
  • Nutrition has so much influence on our immunity! Every part of our immune system and function involves micronutrients. Protein, a macronutrient, also plays a crucial role since protein provides the building blocks to create the cells that fuel our immune system. While good nutrition plays such an important role in supporting and boosting our immunity, poor nutrition can also dampen our immune system. Therefore, healthy eating is so important during this pandemic and should be emphasized!

• What are some specific nutrients that are related to infection-defense?
  • Vitamin D, Vitamin C, Vitamin A, and Zinc! There continues to be a lot of research showcasing the importance of maintaining good vitamin D serum levels. Vitamin D deficiency appears to be related to the incidence and severity of COVID-19.  Vitamin D deficiency impairs the innate immune system. Vitamin A and Vitamin C are two important antioxidants that support immune function and help combat inflammation. Zinc affects multiple aspects of our immune system and function which include supporting our white blood cells. However, I always caution patients with starting supplementation on their own without proper guidance from a Dietitian. For instance, if someone supplements with too much zinc for too long, without proper balance of copper, they can give themselves a copper deficiency. Nutrients work synergistically with one another, so balance is important!

• How can we formulate a diet to optimize the immune system?
  • An anti-inflammatory diet focused on whole, real foods is key to obtaining the important vitamins, minerals, and antioxidants needed to support our immune function and fight off oxidative stress. This should include a balance of good quality protein (wild-caught fish, seafood, organic poultry, eggs, grass-fed beef, beans & lentils), whole food carbohydrates (berries, apples, beets, sweet potato), and healthful fats (olive oil, avocado, flaxseed) to support a healthy glucose and insulin response. Including a variety of colorful vegetables and fruits provide antioxidants, and dietary fiber to support our microbiome. Up to 80% of our immune system resides in our gut! Inflammatory foods like sugar, trans fat, refined oils, and alcohol should be avoided or limited as much as possible. Sugar and alcohol can both suppress the immune system and offer little to no nutritional value.

• What supplements would you encourage to optimize immunity?
  • Vitamin D is usually the supplement I recommend most often since most Americans have suboptimal or insufficient levels today. Especially those residing in more northern latitudes. (Looking at you Philadelphia). However, I think it’s important to check one’s Vitamin D blood serum levels prior to initiating supplementation so the correct dose can be chosen. For most adults however, 1000-2000 IU of D3 is a safe maintenance dose. I also like to use Vitamin C, Zinc, Vitamin A, Glutathione, and Melatonin.

• Are there any other wellness recommendations you would encourage to adapt, like lifestyle changes?
  • Absolutely! In addition to a healthy diet, prioritizing sleep is crucial in supporting immunity. Sleep deprivation suppresses immune system function and renders our ability to fight off infections. We should aim to get 7-8 hours of sleep per night.  I also recommend practicing stress management. When we are stressed, a hormone called cortisol is released. Although we require some cortisol under normal conditions, chronically elevated cortisol can become problematic. High cortisol levels can lead to impaired immune function. Lastly, I encourage getting outside in nature and being active! Being in nature can reduce stress, support our natural circadian rhythm to support healthy sleep cycles, and even increases microbial diversity!

Helping eating habits is important now more than ever to build a strong defense against COVID-19 and other infections. For all these reasons, we believe in the importance of nutrition, not only now but also in the future.