How To Keep Your Immune System Healthy, According To Experts

How To Keep Your Immune System Healthy, According To Experts

This article originally appeared in Forbes.

With the colder months just around the corner and the third wave of coronavirus (SARS-CoV-2) upon us, taking care of our immune system is more important than ever. 

Our immune system is the first line of defense against infection and disease. Although "scientifically there is no way to boost your immunity, there are certain lifestyle changes you can adopt to maintain a balanced immune system—one that can respond appropriately to infection and heal and repair any damage that may occur in the process," says Dr. Jenna Macciochi, immunologist and author of Immunity: The Science of Staying Well.

Here, three health experts share key tips you can start following right now to maintain a robust immune system:

  • Load up on Vitamin C: "When you’re sick, your body uses more vitamin C, so keeping your body topped up is important and may help to reduce the time you are unwell," says Rhiannon Lambert, London-based registered nutritionist and host of Food for Thought podcast. "Vitamin C helps support the production and function of the special types of white blood cells that attack bacteria and viruses," explains James Collier, head nutritionist at complete nutrition brand, Huel. "While the popular idea of vitamin C preventing the common cold has been exaggerated, a good vitamin C intake of at least the RDA is essential for an efficient immune system," notes the nutrition expert. “It is important to note you can only get this water-soluble vitamin from the diet as it cannot be stored in the body," Lambert points out. Foods like orange, bell pepper, strawberry, kiwi, broccoli, guava, tomato and kale are some of the best sources of Vitamin C. You can also try drinking Vita Coco coconut water for some additional vitamin C, suggests Lambert. "A 500ml carton of Vita Coco coconut water contains 90mg of vitamin C," tells Lambert. 

  • Eat more protein: "Protein is well known for its ability to help build muscle, but it’s actually also vital for supporting immunity," notes Collier. "Getting adequate protein is really important as it makes up the building blocks that help our immune system to make new cells and antibodies to fight infection," explains Dr. Macciochi. "Consuming at least the RDA or above of protein will help keep your immune system strong and sturdy," says Collier. Fatty fish, lean chicken, beans, tofu, lentils, nuts and seeds are good sources of protein. 

  • Get enough Vitamin D: Also known as the 'sunshine' vitamin as our bodies can make Vitamin D from sunlight, this nutrient helps support several different white blood cells to protect the body against foreign invaders, explains Collier. Oily fish, such as salmon and trout, are excellent sources of vitamin D. One of the next best sources of vitamin D are eggs—which contain 11% of the US RDA, followed by cheeses including Fontina, Muenster, and Monterey, tells the nutritionist.

  • Drink more H2O: "Staying hydrated is super important when it comes to the immune system," says Collier. "The mucus in the mouth, nose and respiratory tract is on the front line when it comes to protecting your body against foreign invaders. If you’re dehydrated, you’ll make less mucus and this quite simply means you’ll be less protected. This is an added stressor to the body and can increase susceptibility to infection, so it’s important to drink up," he explains. An average adult should consume at least three liters of fluids per day. "A general rule of thumb for healthy people is to drink two to three cups of water per hour, or more if you're sweating heavily," suggests a Harvard Health report

  • Balance your plate: "Building a fighting fit immune system comes down to eating a varied diet and ensuring our bodies get their recommended dietary allowances (RDAs) for all essential nutrients," says Collier. Besides protein, fiber and Vitamins A, C, D and E, other essential micronutrients for a healthy immune system include iron, zinc, selenium, and vitamins B6 and B12. "Always aim for a food first approach," says Dr. Macciochi. While "supplements might seem like a quick fix but unless you are deficient, there is little benefit from taking more than you need," adds the immunologist.

  • Take care of our gut: Taking care of your gut health is another essential way to strengthen your immunity, tells Dr. Macciochi. The gut flora or gut microbiota not only regulates the body's metabolism but its immune system as well. "Healthy intestinal barrier function allows certain gut-derived molecules to get into the body while keeping others out. This supports better immune and brain performance," explains Dr. Sara Adães in a detailed report on the connection between gut microbiota and the immune system. Eating more fiber-rich foods like whole grains, seeds and veggies and fermented foods such as yogurt, tempeh and kombucha while limiting your intake of processed foods are some of the best ways to improve your gut health. 

  • Make sleep a priority: Getting good quality and quantity of sleep is crucial for a balanced immune system, says Dr. Macciochi. When you are asleep, your body produces cytokines—a protein that regulates your body's immune and inflammation responses. In addition, the human body also produces a type of white blood cell called T-cells during sleep that destroy infected cells and regulate the body’s immune response. According to the Centres for Disease Control and Prevention (CDC), an average adult needs at least seven hours of restful sleep every night for optimal health. 

  • Move often: Both Lambert and Dr. Macciochi stress that regular moderate exercise is essential for supporting your immune system. Moderate to intense physical activity reduces stress, fights inflammation and increases the blood flow which in turn keeps the immune cells, particularly T-cells, circulating rapidly through the bloodstream—all of which help your immune system in the long run. According to the U.S. Department of Health and Human Services (HHS), adults should get a total of at least 150 minutes of moderate-intensity exercise or a minimum of 75 minutes of vigorous activity—plus muscle-strengthening exercises—at least twice a week. Here are some trainer-approved, no-equipment exercises you can easily do at home.

  • Try to limit stress: Managing your stress levels is also incredibly important for maintaining a healthy immune system, notes Dr. Macciochi. Chronic stress can make you susceptible to illness and disease as it weakens the immune system's ability to combat infection. Here's how to de-stress in five minutes or less. Doing meditation, exercising, listening to music and talking to a loved one are also great ways to alleviate stress.