Immune Boosting Nutrients
As the colder months approach, it's important to take extra care of our immune system. With the change in weather and the increased likelihood of colds and flu, it's essential to give our bodies the support they need to fight off infection and stay healthy. Luckily, there are many nutrients that can help boost our immune system and keep us feeling our best throughout the colder months. In this blog, we'll explore the effects of various nutrients on the immune system and what foods they’re found in so that you can incorporate them into your diet to help you stay healthy. So, let's dive in and discover how we can support our immune system as the cold weather sets in.
Vitamin C
Vitamin C is a powerful antioxidant with immune boosting properties. It helps to support the function of immune cells, which can help to improve the body's ability to fight off infections. In fact, vitamin C has been shown to significantly reduce the duration and severity of colds and other respiratory infections in a dose dependant manner [1].
Vitamin C is found in many fruits and vegetables. Some of the best sources of vitamin C include oranges, lemons, grapefruits, kiwi, strawberries, papaya, red and green capsicums, broccoli, Brussels sprouts, spinach, tomatoes, sweet potatoes, and cauliflower. Vitamin C is easily destroyed by heat and oxygen, so it is best to eat these foods raw or lightly cooked and avoid slicing and storing away to preserve their vitamin C content.
Vitamin D
Numerous studies have concluded the beneficial effects of vitamin D in regulating the immune system. Studies have found that vitamin D deficiency is associated with an increased risk of infections, including respiratory infections, such as the common cold, influenza, COVID-19 and pneumonia [2, 3].
Vitamin D helps to stimulate the production of antimicrobial peptides and regulate the function of immune cells, including T cells and B cells, which play a key role in fighting off infections [2, 4, 5, 6]. Vitamin D also helps to regulate the inflammatory response, which is important for controlling infections and preventing damage to healthy tissues [2,5].
The best way to increase vitamin D levels are through sun exposure; however, you can also find vitamin D in some foods such as salmon, mackerel, tuna, and egg yolks. I recommend downloading an app such as “D-Minder” on to your phone which helps to calculate how much vitamin D you are getting from the sun based on individual factors. It provides recommendations for how long you should spend in the sun each day to maintain optimal vitamin D levels.
Quercetin
Quercetin is a flavonoid, a type of plant pigment that is found in many fruits, vegetables, and grains. It is known for its antioxidant and anti-inflammatory properties, and it has several benefits for the immune system.
Quercetin exhibits antiviral properties, which can help to reduce the risk of infections and regulate inflammation associated with them [7]. Several studies have found that quercetin may help to inhibit the replication of the influenza virus, which may reduce the severity and duration of infections [7, 8, 9]. Quercetin has also been shown to have a protective effect against lung induced injuries [10].
Quercetin is found in a variety of plant-based foods, including fruits, vegetables, and grains. Some of the best sources of quercetin include red onions, kale, cranberries, apples, citrus fruits, berries, broccoli and tomatoes. Cooking can reduce the amount of quercetin in foods, so it's best to eat these foods raw or lightly cooked to preserve their quercetin content.
Zinc
Zinc influences the normal development and function of the innate immune system, neutrophils and natural killer cells which are responsible for fighting off infections [11]. Studies have found that zinc deficiency is associated with an increased risk of infections, particularly respiratory infections, such as the common cold, influenza, and pneumonia.
Zinc also helps to support the function of the skin and mucous membranes, which act as a barrier against infections [11]. It helps to maintain the integrity of these tissues, which can help to prevent infections from entering the body [11].
Zinc is found in a variety of foods, including oysters, beef, pork, and chicken, legumes, beans, lentils, chickpeas, nuts, and seeds.
Resveratrol
Resveratrol is a naturally occurring polyphenol compound found in plants. Evidence suggests that resveratrol may have immune boosting and anti-inflammatory properties, which may help to reduce some of the symptoms associated with colds, such as coughing and congestion [12]. Additionally, resveratrol has antioxidant properties, which can help to protect the body from damage caused by free radicals [12]. Resveratrol is found in many foods including red grapes, blueberries, cranberries, peanut skins, rubarb and dark chocolate.
Taking care of our immune system during the colder months is crucial to stay healthy and prevent illness. Incorporating nutrient-dense foods into our diet can help support our immune system and boost our overall health. Nutrients such as vitamin C, vitamin D, quercetin, zinc and resveratrol have been shown to have positive effects on the immune system and can be found in many wholefoods. By prioritizing our health and taking steps to support our immune system, we can enjoy a happy and healthy winter season.
Yours in health and happiness,
Ebony x
References:
[1] Bucher, A., & White, N. (2016). Vitamin C in the Prevention and Treatment of the Common Cold. American journal of lifestyle medicine, 10(3), 181–183. https://doi.org/10.1177/1559827616629092
[2] Ben-Eltriki, M., Hopefl, R., Wright, J. M., & Deb, S. (2022). Association between Vitamin D Status and Risk of Developing Severe COVID-19 Infection: A Meta-Analysis of Observational Studies. Journal of the American Nutrition Association, 41(7), 679–689. https://doi.org/10.1080/07315724.2021.1951891
[3] Grant, W. B., Lahore, H., McDonnell, S. L., Baggerly, C. A., French, C. B., Aliano, J. L., & Bhattoa, H. P. (2020). Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients, 12(4), 988. https://doi.org/10.3390/nu12040988
[4] Bergman, P., Norlin, A. C., Hansen, S., Rekha, R. S., Agerberth, B., Bjorkhem-Bergman, L.,
… Andersson, J. (2012). Vitamin D3 supplementation in patients with frequent
respiratory tract infections: A randomised and double-blind intervention study.
BMJ Open, 2(6), 1-10. https://doi.org/10.1136/bmjopen-2012-001663
[5] Gombart A. F. (2009). The vitamin D-antimicrobial peptide pathway and its role in protection against infection. Future Microbiology, 4(9), 1151–1165. https://doi.org/10.2217/fmb.09.87
[6] Youssef, D. A., Miller, C. W., El-Abbassi, A. M., Cutchins, D. C., Cutchins, C., Grant, W. B., & Peiris, A. N. (2011). Antimicrobial implications of vitamin D. Dermato-endocrinology, 3(4), 220–229. https://doi.org/10.4161/derm.3.4.15027
[7] Mehrbod, P., Hudy, D., Shyntum, D., Markowski, J., Łos, M. J., & Ghavami, S. (2020). Quercetin as a Natural Therapeutic Candidate for the Treatment of Influenza Virus. Biomolecules, 11(1), 10. https://doi.org/10.3390/biom11010010
[8] Wu, W., Li, R., Li, X., He, J., Jiang, S., Liu, S., & Yang, J. (2015). Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry. Viruses, 8(1), 6. https://doi.org/10.3390/v8010006
[9] Di Petrillo, A., Orrù, G., Fais, A., & Fantini, M. C. (2022). Quercetin and its derivates as antiviral potentials: A comprehensive review. Phytotherapy research, 36(1), 266–278. https://doi.org/10.1002/ptr.7309
[10] Choirur Rizky, W., Candragupta Jihwaprani, M., Mushtaq, M. (2022). Protective mechanisms of quercetin in various lung-induced injuries. SCIREA J Clin Med. 7:206–223. https://doi.org/10.54647/cm32844
[11] Prasad A. S. (2008). Zinc in human health: effect of zinc on immune cells. Molecular medicine, 14(5-6), 353–357. https://doi.org/10.2119/2008-00033.Prasad
[12] Malaguarnera L. (2019). Influence of Resveratrol on the Immune Response. Nutrients, 11(5), 946. https://doi.org/10.3390/nu11050946
