As we head into flu season with COVID19 surging in many areas, we’re all concerned with ways to avoid getting sick. Staying home, maintaining social distance, regular handwashing, and wearing masks are our best ways to protect ourselves until the majority of the population is vaccinated.
Eating a nutritious diet can improve our immune systems to not only prevent us from getting ill, but reducing the risk of serious complications if we do get sick. Let’s take a look at what nutrition can do for you!
Protein is one of three macronutrients and is needed for strong immunity. Protein provides materials for our bodies to make antibodies, white blood cells, and other compounds that help fight disease. Protein is also necessary for wound healing and recovery from disease.
Most people associate animal foods with protein, which is true. Eggs, beef, fish, poultry, pork, and shellfish all provide protein, but so do soy-based foods (edamame, tofu, soy milk, or soy nuts). Beans, lentils, peas, nuts, seeds, nut butter, and quinoa, a seed from Peru, are also good sources of protein.
Whole grains and vegetables contain small amounts of protein, with the exception of soy, they aren't considered complete proteins since they're missing some essential amino acids. Combining rice and beans or peanut butter on wheat bread makes the two a complete protein. But you don't have to do worry about getting complete protein in one meal because you are likely to eat a variety of foods containing them throughout your day.
Vitamin D has been in the spotlight most recently as research suggests that individuals with vitamin D deficiency are more likely to contract COVID and suffer more severe consequences when they do.1 Vitamin D improves the ability of white blood cells in your immune system to fight disease and also reduces inflammation, which may cause cell damage.
This fat-soluble vitamin can be found in dairy products as well as fortified juice or cereal, fatty fish, and through casual sunlight exposure. It's difficult to get enough through our diet.
If you’re over 50, have an autoimmune disease (such as MS, RA, or Lupus), suffer lactose intolerance, have kidney, pancreatic, or liver disease or obesity, you’re at higher risk for vitamin D deficiency. Ask your doctor to check your vitamin D level and follow supplementation recommendations if needed.
Vitamin C impacts immunity in a number of ways. For starters, it supports the skin’s barrier function against pathogens and promotes antioxidant activity in the skin, which protects it from oxidative stress. Vitamin C also collects in phagocytic cells- the type of cells that “eat up” bacteria and aid in getting rid of them. It helps with ridding the body of spent neutrophils from infection sites, which decreases the chance of tissue damage.
Vitamin C deficiency results in impaired immunity and a higher risk of infections. Deficiency of this water-soluble vitamin can be prevented through regular intake of fruits and vegetables like peppers, citrus fruits, berries, broccoli, and tomatoes.
Most people think of iron when they think of the health of their blood, but this mineral is quite important in immunity. Iron is needed for cell differentiation and cellular growth. It’s a key component in enzymes that are vital for the normal functioning of immune cells.
Iron is part of hemoglobin, which carries oxygen to our body’s cells, tissues, and organs. It’s also needed for our body’s ability to fight infection. Iron-deficiency is linked with poor immunity.
Iron-rich foods include beef, poultry, and pork as well as lentils, quinoa, and iron-fortified foods such as bread and cereals. Consuming a food high in vitamin C improves the absorption of non-animal forms of iron.
Zinc lozenges are popular during cold and flu season, but zinc is fairly widespread in our diet, too. Zinc is needed to help activate over 300 enzymes in the body and helps with the integrity of our skin, similar to vitamin C. In addition, zinc is needed for immune-modulating cells such as neutrophils and killer cells. Zinc deficiency is linked with a higher risk of infection.
While zinc won’t “cure” a cold, some studies suggest it may reduce symptoms and duration of the illness. It has been linked with reduced severity of COVID. 2
Zinc is found in oysters, beef, whole grains, nuts, seeds, and legumes. Excessive supplements may cause a decrease in HDL (healthy) cholesterol levels. 3
Here are some tips to protect your immune system:
- Include a variety of fruits and vegetables in your diet daily. Sources of vitamin C include peppers, berries, broccoli, citrus fruits, and spinach.
- Obtain protein in your diet with lean cuts of meat, low-fat dairy products such as Greek yogurt or string cheese, or dried beans and lentils.
- Add whole grains to your diets such as oatmeal, whole-wheat pasta, bran cereal, or quinoa for adequate zinc and fiber.
- Add berries to iron-fortified cereals to boost iron absorption or include peppers and tomatoes in bean dishes.
- Drink plenty of water. Water helps keep mucous membranes moist, which helps protect the lining of our lungs and gut from harmful bacteria. Aim for at least 6 to 8 cups of water daily.
- Get enough vitamin D in your diet through dairy products, fatty fish, or dietary supplementation (if needed).
Finally, getting enough sleep, reducing stress, and doing regular exercise also improve our immune systems and should be accomplished every day.
Lisa Andrews, MEd, RD, LD
- Ali N. Role of vitamin D in preventing COVID-19 infection, progression, and severity. J Infect Public Health. 2020 Oct;13(10):1373-1380
- Wessels I, Rolles B, Rink L. The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis. Front Immunol. 2020;11:1712. Published 2020 Jul 10. doi:10.3389/fimmu.2020.01712
- Bulka CM, Persky VW, Daviglus ML, Durazo-Arvizu RA, Argos M. Multiple metal exposures and metabolic syndrome: A cross-sectional analysis of the National Health and Nutrition Examination Survey 2011-2014. Environ Res. 2019 Jan;168:397-405.
- Marsh KA, Munn EA, Baines SK. Protein and vegetarian diets. Med J Aust. 2013;199(4 Suppl):S7-S10.
Lisa Andrews, MEd, RD, LD, is a registered dietitian and owner of Sound Bites Nutrition in Cincinnati. She shares her clinical, culinary, and community nutrition knowledge through cooking demos, teaching, and freelance writing. Lisa is a regular contributor to Food and Health Communications and Today’s Dietitian and is the author of the Healing Gout Cookbook, Complete Thyroid Cookbook, and Heart Healthy Meal Prep Cookbook. Her line of food pun merchandise, Lettuce beet hunger, supports those suffering food insecurity in Cincinnati. For more information, visit her website: https://soundbitesnutrition.com/