Debunking Immune System Myths

by Jessica Pastuf

Hey Utes! We hope you're hanging in there. We know there is an abundance of information circulating, and there is much to do with boosting your immunity in the face of COVID-19, so we want to lay down the facts for you here. We will discuss a few "hot topic" nutrients in the realm of boosting the immune system, and then discuss the known facts to support proper immune functioning both during COVID and beyond.

First and foremost, as is widely emphasized, practicing social distancing and proper hygiene (hand-washing, disinfecting surfaces and homes, and wearing a cloth face mask in public) are the best known ways to protect yourself from being exposed to COVID-19. 

With that in mind, now let's talk the immune system game. Here are the main players:

1) Adequate calorie (energy) and protein intake

2) Ample fruits and vegetables 

3) Getting enough sleep

4) Managing Stress

5) Probiotics (Kiefer, kimchi, tempeh, Greek yogurt, pickles, miso)

6) Vitamin D (sunlight, fortified foods - milk and juices) 

7) Heart healthy fats 

8) Hydration

9) Exercise 

You might be wondering, about the vitamin that seems to get all the credit for immunity -Vitamin C.

Adequate intake of vitamin C is important to support the immune system, however, vitamin C is only one of many nutrients that plays a role. This point highlights the importance of a well-rounded diet, with a variety of fruits and vegetables to support ample levels of vitamin C intake. In fact, vitamin C has been a hot topic of many researchers, and ultimately, there is little-to-no evidence to suggest taking a vitamin C supplement will help to cure sickness. Rather, there is evidence to suggest maintaining adequate intakes of vitamin C, through diet, can help to decrease your chances of getting sick. So the moral of the story, slow your impulse to purchase any Emergen-C. 

Zinc has also gained popularity in the media to be a necessary immune booster. It is true, zinc plays a role in various components of health, including the formation of key immune cells. However, zinc deficiency is extremely rare in the U.S. Zinc is found in various food sources including: beef, pork, poultry, seafood, dairy, nuts, legumes, fortified breakfast cereals and whole grains. By eating a varied diet, overall healthy individuals can rest assured they are getting enough zinc. Similar to Vitamin C, there is overall conflicting evidence to suggest that a zinc supplement will cure or prevent sickness, therefore you may want to think twice before allocating money to supplements. On that note though, as always, if you choose to use a supplement, choose safely. Look for third party certified logos such as NSF and reach out to your sports RD for further guidance. 

Okay, now that that's out of the way, we can discuss the roles of the main players. Let's start with calorie and protein intake.  Just like your muscles, the immune system requires energy to work at its best. Many of the components of the immune system are proteins, highlighting the need for adequate dietary protein intake to support immune system function. With inadequate energy coming in, the body has to go in conservation mode. One of the first systems to take the backseat, is the immune system. To support immunity, fuel frequently and don't skip out on your lean proteins. 

Next, remember the phrase "eat the rainbow". Fruits and vegetables of different colors have unique nutritional benefits including antioxidants and phytonutrients which both help to reduce inflammation and support immune functioning. Of course by consuming a variety of fruits and vegetables throughout the day you are much more likely to get enough Vitamin C too! 

Managing your sleep and stress go hand-in-hand to support immunity, just like it does performance. Inadequate sleep and overt stress causes hormonal changes in the body which can lead to inflammation and ultimately suppression of the immune system. Being well-rested and calm will help to support better training sessions and performance, and to keep you healthy. 

Probiotics promote a healthy gut by introducing "good bacteria" into the body. Such good bacteria can help to promote the growth of immune fighting cells, and send signals throughout the body to help decrease inflammation and the overall immune response. Increasing your intake of probiotic rich sources can help to keep you gut, and your immune system happy, and healthy. Need help identifying probiotic rich sources? Check in with your sports RD,  and keep an eye out for an upcoming blog post all about probiotics! 

Vitamin D is a fat soluble vitamin, meaning it requires dietary fat to do its job in the body.  Although best known for its role in bone health, Vitamin D also plays a fundamental role in supporting the immune system. Vitamin D is needed for the production and function of specific immune system cells (e.g. T-cells and macrophages) which both help your body to fight against sickness. Vitamin D seems to play a protective role specifically in defending respiratory illnesses, most notably upper respiratory tract infections. While vitamin D is limited in our foods, sources such as salmon (or other fatty fish), egg yolks, and fortified milk or juice all add to your vitamin D intake. However, for most people the best source of vitamin D comes from the sun. Spending about 30 minutes per day, with most of your arms and legs exposed to sunlight (without sunscreen) is usually sufficient to get the Vitamin D you need to stay healthy. In some cases, vitamin D supplements are needed. In the case of vitamin D it is recommended to have your levels measured before beginning to take a supplement to ensure you take a proper dose and to check with your sports RD or physician to ensure you are taking the correct dose of a supplement to meet your needs. More info to come in future blog posts about vitamin D too! 

Heart healthy fats are beneficial for overall health, and specific to the immune system, they too help to reduce inflammation. A diet rich in health fats will also support the function of Vitamin D. 

Staying hydrated is important to support optimal functioning of all parts of the body. Adequate hydration is needed to support blood flow, and the transportation of nutrients throughout the body. Hydration is the basis for tissue repair and recovery, which is relevant to the immune system too. And, don't forget about the importance of electrolytes (salt and potassium) to help you to stay hydrated. 

Lastly, exercise. As athletes, this usually comes naturally, but may seem foreign during this time of unstructured training. Remaining active, even when off the field, or outside the weight room, can help you to stay healthy. Find a cute dog to walk, break out your yoga mat, or hop on a bike. Structured exercise is great, but the most important thing is to stay active, and hey, maybe even have little fun to help reduce stress while you're at it! 

In the end, eating a well-balanced diet, sleeping, and staying active and calm will be your best tools now during COVID-19, and at all times to stay strong and to stay well.  

Okay - that was a lot! Have any questions? Intrigued about any of this information? Reach out to any of the Utah Sports Nutrition staff members for more information!