Vitamin C, Zinc, Echinacea and your Immunity
May is often a time to think about your immune system and what you can do for it to help ward off infection during the cold and flu season. 2020 has brought with it new challenges and boosting immunity likely ranks high on everyone’s priority. Vitamin C, Zinc and Echinacea and known natural immune boosters and are a must to think about consuming on a regular basis.
Vitamin C or ascorbic acid is an essential nutrient for humans in that we cannot synthesis it ourselves or store excess amounts. The best sources of Vitamin C include citrus fruits, capsicum, chilli, kiwifruit, strawberries, tomatoes, broccoli and Brussels sprouts. By eating the recommended 2 serves of fruit and 5 serves of vegetables from varied sources per day you are likely to ingest more than 200mg Vitamin C. Our current recommended daily intake (RDI) is 45mg per day for healthy Australian adults.
During times of infection and stress concentration of vitamin C in the body decrease, thus it is believed to play an integral role in our immune system. Vitamin C is a powerful antioxidant and has been shown to help regenerate other antioxidants, which reduces free radicals and inflammation in the body. It is found in phagocytic cells (cells that protect the body by ingesting harmful foreign particles) and natural killer cells, thus helping to boost our immune systems response when an infection if present.
Research has not proven that Vitamin C can prevent you catching a cold, but there is evidence doses greater than 200mg per day can decrease the length and severity of a cold or flu. Higher doses of Vitamin C have been shown to be more beneficial in people with compromised immune systems such as the elderly and smokers.
Another nutrient to be sure you get enough of during cold and flu season is Zinc. Zinc is critical for healthy cell development and function. It is needed for gut health, wound healing, blood clotting as well as reducing the severity of cold and flu symptoms. Eat oysters, lean red meat, crab, lobster, baked beans, pumpkin seeds, fortified cereals, cashew nuts and chickpeas to help boost your zinc intake.
The RDI for zinc is 14mg per day in healthy adult males and 8mg per day in healthy adult females. Studies have shown that supplementation with 30mg per day has beneficial effects on the immune system and reducing the severity and length of a cold or flu.
Some key components of your immune system require zinc for normal function. Zinc helps to develop and activate T-lymphocytes and neutrophils. T-lymphocytes come from stem cells in the bone marrow and help protect the body from infection. Neutrophils are the white blood cell that is the first responder when an infection or issue is present. Even a mild deficiency can impair immune function, hence it is important to consume daily.
Echinacea is one of the most widely used herbal medicines. It is a bright pink/purple daisy looking flower that grows in the USA, well known for its immune system benefits and relieving cold and flu symptoms.
Its immune benefits and anti-inflammatory properties come from the many phytochemicals, antioxidants and other compounds it contains. In studies these have been shown to increase macrophage and natural killer cell activity. Macrophages are large white blood cells that put simply eat and destroy microbial pathogens. Macrophage activity stimulates natural killer cells, which assist to contain viral infections. Antioxidants help prevent cell damage from oxidative stress, which in turn reduces inflammatory processes within the body.
A Cochrane review published in 2014 found that Echinacea may reduce the relative risk of catching a cold by 10-20%. Note though that the studies reviewed used a number of different Echinacea preparations including dry powders and liquids from both the root and/or flower of the plant. It is not yet known which Echinacea preparation works best, and there is no best-known dose. Always follow the recommendations of the product you choose to avoid negative effects.
As always, as well as boosting your intake of Vitamin C, Zinc and Echinacea, a healthy diet including a wide variety of vegetables, fruits, wholegrains and lean protein should be followed to support an optimal immune system.
Barrett, B, 2003 “Medicinal properties of Echinacea: A critical review”. Phytomedicine, Vol 10, issues 1, pg 66-86
Carr, A.C, Maggini,S, 2017 “Vitamin C and Immune Function
”. Nutrients. 2017 Nov #, Vol 9, Issue 11
Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. “Echinacea for preventing and treating the common cold”. Cochrane Database of Systematic Reviews 2014, Issue 2. Art. No.: CD000530.
Manayi, A, Vazirian, M, Saeidnia, S, “Echinacea purpurea: Pharmacology, phytochemistry and analysis methods”. Pharmacogn Rev. 2016 Vol 9, Issue 17 pg 63-72
Prasad, A, S, 2009 “Zinc: role in immunity, oxidative stress and chronic inflammation”. Curr Opin Clin Nutr Metab Care. Vol 12, Issue 6 pg 646-52.
Prasad, A, S, 2008 “Zinc in Human Health: Effect of Zinc on Immune Cells”. Molecular Medicine. Vol 14, Issue 5-6, pg 353-57.
Wintergerst, E,S, Maggini, S, Hornig, D, H, 2006 “Immune-enhancing role of vitamin C and zinc and effect on clinical conditions”. Ann Nutr Metab. Vol 50, Issue 2, pg 85-94,