January 2021 Issue
By KC Wright, MS, RDN
Vol. 23, No. 1, P. 10
Is it really efficacious in the prevention and treatment of the cold, flu, and COVID-19?
Here we are in the midst of cold and flu season, but worse, we’re also fighting COVID-19, the disease caused by the novel coronavirus. To prevent and/or treat these infections, many clients have turned to elderberry supplements, lauded to possess immune-stimulating, antiviral, and other properties. But does elderberry really make a difference? This article examines the health claims for elderberry, considers the latest research findings, and provides recommendations for clients and patients.
Elderberry is the dark purple berry of the European or black elder tree (Sambucus nigra). It grows in warm areas of Europe, North America, Asia, and North Africa. Elderberry has been used as a folk medicine for centuries to fight infections and boost immunity. Elderberry is a rich source of phenolic compounds, particularly anthocyanins that give the fruit its dark color, similar to those found in blueberries and blackberries. In addition, elderberry contains flavonoids, such as quercetin, which have been found in laboratory tests to possess a variety of biochemical and pharmacological actions, including antioxidant and immunologic properties. As an ingredient, elderberry traditionally was added to food for flavoring and in the preparation of jams, wines, and pies.1
Both the berries and flowers of the elderberry tree are edible, but elderberries need to be cooked before being consumed to eliminate the toxin sambunigrin. Raw, unripe elderberries along with the leaves and stem of the elderberry tree can cause nausea, vomiting, and diarrhea; in large quantities, the toxin may cause serious illness.2 Powders, concentrates, and extracts of elderberry typically are made with only the berry and are processed to remove toxins.3 Consumers can buy elderberry formulated in cough syrups, gummies, lozenges, and immunity juice shots.
Efficacy for Colds and Flu
As dietary supplements, elderberry products have been prepared and packaged to support colds, flu, and other conditions. Most recently, rampant marketing claims have promoted
elderberry to prevent COVID-19, although sales of elderberry supplements and products containing elderberry already had begun to demonstrate enormous growth. In 2018, elderberry became the fourth top-selling herbal supplement, a 138% increase from 2017.4
Most of the current research on elderberry has focused on immunity and antiviral activity. Laboratory studies have shown that an extract of elderberry (Sambucol, Razei Bar Ltd) can increase cytokines, proteins that fight infection. Elderberry extract and certain elderberry flavonoids also have been shown to reduce the replication of influenza A and B.3
In human clinical studies, though, data on whether elderberry is beneficial for the cold or flu are mixed. Preliminary research published in 2004 involving elderberry extract supplements showed a shortened duration of the flu by four days when compared with placebo.5 A 2014 systematic review highlighted two small studies that showed elderberry extract shortened the duration and lessened the symptoms of the flu compared with placebo, but recommended additional, large well-designed clinical trials to confirm these outcomes.1 Several small, company-funded clinical studies have suggested elderberry may reduce the symptoms and shorten the duration of the cold and flu, but a study not company funded didn’t show benefit.3
Yet, one study published in September 2020, one of the largest to date evaluating elderberry in the treatment of flu patients, showed no difference in the severity or duration of symptoms between elderberry and placebo.6 This affirms the need for further research, specifically well-conducted human clinical trials for elderberry, especially as a monotherapy. Elderberry also has been suggested to improve CVD biomarkers. However, consumption of a supplement containing elderberry anthocyanins for 12 weeks showed no improvement, nor did the supplement positively affect fasting blood glucose levels or kidney or liver function.7
According to ConsumerLab.com, an independent agency that tests the quality of dietary supplements, “Relying on an elderberry supplement to reduce or shorten cold or flu symptoms requires a big leap of faith” for several reasons. Many companies that make elderberry products fund the clinical trials, and they haven’t been able to quantify and therefore standardize the level of compound needed to determine efficacy. In addition, the formulations allegedly used don’t match the contents of the products tested. Much of the research on elderberry used the Sambucol extract, which was standardized as 38% elderberry extract. Yet, the various Sambucol products currently on the market may differ in the amount of extract they contain and have other added ingredients.
Impact on COVID-19
Currently, there are no published studies that have evaluated the use of elderberry in the treatment of COVID-19.2 In fact, the FDA and the Federal Trade Commission have taken action against companies that have marketed products with unsubstantiated claims of efficacy for COVID-19.2,8
Elderberry can be harmful to those who have COVID-19. Due to the immune supportive actions of elderberry, it increases the release of a cytokine called interleukin 1 beta, which is part of the inflammatory reaction to COVID-19 that can result in acute respiratory distress.9 Elderberry has the potential to aggravate the inflammatory “cytokine storm” that occurs when the body overreacts to the coronavirus in severe COVID-19 infections and damages the lungs.10 Therefore, elderberry shouldn’t be taken by anyone who tests positive for the virus.
Similar to other dietary supplements, neither the FDA nor any other regulatory agency tests elderberry for quality. However, in 2020, ConsumerLab.com tested two of eight elderberry supplements and five of 25 elderberry extracts for quality and found they contained no elderberry.3 Fourteen of the extracts included low amounts of a key flavonoid, cyanidin-3-O-sambubioside.11
In 2019, the United States Pharmacopeia, which standardizes medicines and food for quality and safety, published a monograph specifying that European elderberry extracts should contain specific anthocyanins that are at least 17% of the extract weight.3 The combination of increased consumer demand for elderberry and delayed shipments due to the pandemic also has increased the desire for a reliable and legitimate supply. Manufacturers have experienced difficulties in obtaining high-quality bulk elderberry extracts, as there are some fraudulent suppliers who sell adulterated products. A few US elderberry suppliers have begun to take steps to protect the supply chain by working with other stakeholders to validate analytical methods to identify and authenticate against adulteration.11-12 The chemical make-up of elderberry and many other dietary supplements, as well as the most effective dosing, doesn’t appear to be well defined.
Recommendations for RDs
Due to inconsistent research findings on the efficacy of elderberry to prevent and treat colds, flu, and COVID-19, it’s important for dietitians to remind their clients and patients that there’s no panacea that can replicate eating a healthful diet of whole foods rich in vegetables and fruits to provide them with several immune-boosting vitamins, minerals, antioxidants, and phytochemicals, such as anthocyanins. Along with blueberries and blackberries, other anthocyanin-rich foods include red and black raspberries, red cabbage, black plums and currants, and red radishes. Certainly, other colorful vegetables and fruits, including sweet potatoes, broccoli, apples, and cranberries, also have health-promoting phytochemicals. Staying well hydrated also is vital to help prevent colds and flu, as is good sleep hygiene and regular physical activity. Proper hand washing and avoiding others if you or they aren’t feeling well are essential.
Based on current research and direction from the National Institutes of Health, there isn’t enough information to demonstrate that elderberry is helpful for preventing or treating cold and flu. While some research on elderberry suggests a benefit, it shouldn’t replace medical advice, the flu vaccine, or other recommended treatments. Tell patients they shouldn’t bank on elderberry or other dietary supplements to prevent or treat the cold or flu, and especially COVID-19. Finally, tell patients that it’s also ill advised for them to make their own elderberry home brew or homemade syrup due to news reports of accidental poisoning from inadequate preparation.13
— KC Wright, MS, RDN, is a research dietitian, food and nutrition writer, and advocate for healthful and sustainable food at WildberryCommunications.com.
1. Ulbricht C, Basch E, Cheung L, et al. An evidence-based systematic review of elderberry and elderflower (Sambucus nigra) by the Natural Standard Research Collaboration. J Diet Suppl. 2014;11(1):80-120.
2. Elderberry. National Center for Complementary and Integrative Health website. https://www.nccih.nih.gov/health/elderberry. Updated August 2020. Accessed October 1, 2020.
3. Elderberry supplements review. ConsumerLab.com website. https://www.consumerlab.com/reviews/elderberry-supplements-reviewed/elderberry/. Updated September 24, 2020. Accessed October 2, 2020.
4. Smith T, Gillespie M, Eckl V, Knepper J, Reynolds CM. Herbal supplement sales in US increase by 9.4% in 2018. HerbalGram. 2019;123:62-73.
5. Zakay-Rones Z, Thom E, Wollan T, Wadstein J. Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. J Int Med Res. 2004;32(2):132-140.
6. Macknin M, Wolski K, Negrey J, Mace S. Elderberry extract outpatient influenza treatment for emergency room patients ages 5 and above: a randomized, double-blind, placebo-controlled trial. J Gen Intern Med. 2020;35(11):3271-3277.
7. Curtis PJ, Kroon PA, Hollands WJ, et al. Cardiovascular disease risk biomarkers and liver and kidney function are not altered in postmenopausal women after ingesting an elderberry extract rich in anthocyanins for 12 weeks. J Nutr. 2009;139(12):2266-2271.
8. Fraudulent coronavirus disease 2019 (COVID-19) products. FDA website. https://www.fda.gov/consumers/health-fraud-scams/fraudulent-coronavirus-disease-2019-covid-19-products. Updated November 9, 2020.
9. COVID-19 FAQ. The University of Arizona Andrew Weil Center for Integrative Medicine website. https://integrativemedicine.arizona.edu/COVID19/FAQ.html. Accessed October 2, 2020.
10. Mehta, P, McAuley DF, Brown M, et al. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet. 2020;395(10229):1033-1034.
11. Adulteration of European elder berry extracts on the rise. American Botanical Council website. http://cms.herbalgram.org/BAP/V20/BAM20-IndAlerts.html?ts=1605526512&signature=5051d7debda198608a539a374ecca517. Published September 2020.
12. Krawiec S. Elderberry growth was huge in 2019. Here’s why. 2020 ingredient trends to watch for foods, drinks, and dietary supplements. Nutritional Outlook website. https://www.nutritionaloutlook.com/view/elderberry-growth-was-huge-2019-heres-why-2020-ingredient-trends-watch-foods-drinks-and. Published February 4, 2020. Accessed October 2, 2020.
13. Roy J. No, elderberry will not prevent the flu. Los Angeles Times. October 17, 2019. https://www.latimes.com/lifestyle/story/2019-10-17/elderberry-flu-colds-prevention. Accessed October 5, 2020.