With COVID-19 on everyone’s mind, it’s crucial to maintain a healthy immune system. There are many things you can do to boost your immune system or to keep it from falling behind. Lifestyle changes such as diet and exercise can be incredibly powerful in maintaining the strength of the immune system.
Today, let’s focus on how nutrition can improve immunity and look at some foods you can include in your diet to help keep your immune system healthy.
Citrus fruits (oranges, lemons, etc.) are a great source of vitamin C. We all know vitamin C is beneficial to the immune system. There are a couple of reasons why vitamin C is a powerful immune enhancer.
First, vitamin C boosts your innate immunity. Innate immunity is your body’s ability to protect against a variety of pathogens. Vitamin C supports innate immunity by increasing your body’s ability to keep pathogens out. It strengthens the body’s barriers by increasing collagen production.1 Stronger barriers, fewer pathogens! As a side effect, more collagen will also make your skin smoother and more radiant!
Next, vitamin C increases your acquired immunity. Acquired immunity is your body’s ability to recognize a specific pathogen and remove it. Acquired immunity creates antibodies for specific viruses or bacteria. Vitamin C supports acquired immunity by boosting the cells that produce antibodies.2 More antibodies help clear viruses and bacteria faster, meaning you recover sooner!
Many dairy products are fortified with vitamin D. Vitamin D is not as well-known as vitamin C when it comes to immune health, but it is just as important. Recent studies suggest vitamin D may reduce the risk for COVID-19!3
Scientists are still studying vitamin D to understand how it influences immune health. They think vitamin D likely increases antibody production. Whatever its mode of action, vitamin D is powerful: Supplementing with vitamin D can reduce the risk of influenza by up to 40%!4
Almonds are a good source of vitamin E. Vitamin E is another potent immune enhancer. Like vitamin C, it acts to improve immunity in multiple ways.
First, vitamin E is a powerful antioxidant that removes harmful free radicals and oxidative substances from the body that weaken the immune system.5 This improves both innate and acquired immunity.
Second, vitamin E increases antibody production.5 This supports acquired immunity and allows the body to eliminate existing infections more quickly.
Broccoli is all-around amazing for keeping your body healthy! It supports immune health through multiple vitamins, including vitamins A, C, and E. We’ve already talked about vitamins C and E, so let’s focus on vitamin A.
Like vitamin C, vitamin A supports both innate and acquired immunity. Vitamin A supports innate immunity by improving the body’s natural barriers.6 This prevents pathogens from penetrating and making us ill.
Vitamin A also supports acquired immunity. It improves the body’s ability to produce antibodies. It also regulates antibody function. This helps the immune system in two ways. First, it enhances the effectiveness of antibody function. Second, it helps prevent immune overreaction.7
Maybe with all the COVID-19 news, you’ve heard about a “cytokine storm.” This is a runaway train of immune responses, causing more damage to the body than the infection itself. Vitamin A can help prevent this and keep the immune system functioning properly.
Nutritionists often recommend fish as part of a healthy diet. Artic Flex uses krill oil to support joint health. Who knew shellfish would have other high-powered nutrients!? (We did, actually.)
In addition to healthy oils, shellfish contain high quantities of zinc. Zinc is an essential mineral that supports health in many ways, including boosting the immune system. Zinc supports immune health in a few ways.
First, zinc is an antioxidant. As we mentioned earlier, clearing oxidative substances reduces the number of pathogens entering the body. Second, zinc is involved in producing antibodies.8 Also, it helps cells to form the specialized portions of antibodies that can react with specific viruses and bacteria. Finally, zinc supports the growth of additional immune cells.9
Variety is the Spice of Life
The foods we mentioned benefit the immune system. However, remember that variety is essential in any diet. The nutrients from each of these foods can be found elsewhere.
For example, you might not like shellfish. Or maybe you’re lactose intolerant. That’s not a problem! Zinc and vitamin D are found in many other foods. Eating a variety of healthy foods, including fruits, veggies, and whole grains, is more important than overloading on any one food. Remember: maintain a balanced diet. And maybe eat more broccoli.
- Geesin JC, Darr D, Kaufman R, Murad S, Pinnell SR. Ascorbic acid specifically increases type I and type III procollagen messenger RNA levels in human skin fibroblast. J Investig Dermatol. 1988;90(4):420–424. DOI: 10.1111/1523-1747.ep12460849.
- Feigen GA, Smith BH, Dix CE, et al. Enhancement of antibody production and protection against systemic anaphylaxis by large doses of vitamin C. J Urol. 1983;129(5):1091-1092. DOI: 10.1016/S0022-5347(17)52586-0.
- Grant WB, Lahore H, McDonell SL, et al. Evidence That Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):988. DOI: 10.3390/nu12040988.
- Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza A in Schoolchildren. Am J Clin Nutr. 2010;91(5):1255-1260. DOI: 10.3945/ajcn.2009.29094.
- Meydani SN, Beharka AA. Recent developments in vitamin E and immune response. Nutr Rev. 1998;56(1 pt 2):S49–S58. DOI: 10.1111/j.1753-4887.1998.tb01644.x.
- Stephensen CB. Vitamin A, infection, and immune function. Annu Rev Nutr. 2001;21:167-192. DOI: 10.1146/annurev.nutr.21.1.167.
- Takaki H, Ichiyama K, Koga K, et al. STAT6 Inhibits TGF-beta1-mediated Foxp3 Induction Through Direct Binding to the Foxp3 Promoter, Which Is Reverted by Retinoic Acid Receptor. J Biol Chem. 2008;282(22):14955-14962. DOI: 10.1074/jbc.M801123200.
- Prasad AS. Effects of zinc deficiency on Th1 and Th2 cytokine shifts. J Infect Dis. 2000;182 Suppl 1:S62-S68. DOI: 10.1086/315916.
- Fraker PJ, King LE. Reprogramming of the immune system during zinc deficiency. Annu Rev Nutr. 2004;24:277-298. DOI: 10.1146/annurev.nutr.24.012003.132454.