Elderberry for Cold and Flu: A Review of Published Studies

Elderberries, Sambucus nigra, have a long history of use for upper respiratory infections (colds) and influenza (flu).  In addition to the traditional use of these berries, recent research research has been positive.  Several in vitro and clinical trials have been published supporting elderberries beneficial effect on cold and flu symptoms.

Research has shown that elderberry extract is a safe and effective treatment for cold and flu symptoms. 

A summary of the latest studies:

One of the most well-studied elderberry syrup benefits is its powerful immune-boosting properties. The berries contain chemical compounds called anthocyanidins, which have been proven to have immunostimulant effects (stimulates, or boosts, the immune system) [1].

Several studies have shown elderberry be effective against many different strains of the influenza virus.  Specifically, the flavonoids in elderberry extract bind to the H1N1 human influenza virus as well as the H5N1 avian influenza virus.  When the flavonoids bind to the virus it prevents the virus from replicating and, block the ability of the viruses to infect host cells [2].  Elderberry is also antimicrobial, meaning it can fight bacteria [3].  This is particularly important as bacterial infection during an influenza infection can lead to pneumonia.

A 2004 clinical study showed that when elderberry extract is used within the first 48 hours of the onset of flu symptoms, it can shorten the duration of flu symptoms by an average of four days [4]. Sixty patients suffering from influenza-like symptoms for 48 hours or less were enrolled in this multi-center (4 sites) randomized, double-blind, placebo-controlled study in Norway.  60 patients with verified influenza were enrolled in the study. A standardized elderberry extract (Sambucol®) was used. The subjects were randomly assigned to two groups, and received either 15 ml elderberry or placebo syrup four times a day, during meals, for 5 days. The first dose of medication was given within 48 hours of the onset of the influenza-like symptoms.  Symptoms were relieved on average 4 days earlier and use of rescue medication was significantly less in those receiving elderberry extract compared with placebo. The authors concluded “Elderberry extract seems to offer an efficient, safe and cost-effective treatment for influenza.”

A 2009 pilot study showed elderberry decreased flu symptoms when given within 24 hours of the onset of symptoms [5].  This randomized, double‐blind, placebo‐controlled clinical trial involved sixty‐four patients with three or more flu‐like symptoms. One group was given four doses of 175-milligram proprietary elderberry extract daily, and the other group received a placebo for two days. The group treated with the extract showed significant improvement in most flu symptoms, while the placebo group showed no improvement in symptom severity. Researchers conclude that the extract is effective in controlling influenza symptoms.

A study in 1995 was so encouraging that it turned this ancient remedy into a popular mainstream cold and flu natural remedy.  In this placebo-controlled, double blind study, a complete cure was achieved within 2 to 3 days in nearly 90% of the treatment group, 3-4 days earlier than the placebo group. Patients in the treatment group received black elderberry extract Sambucol®, and included children as well as adults. Children received two, and adults four tablespoons of either Sambucol or its placebo daily for 3 days [6]. 

In 2011, an in vitro study showed elderberry to be effective against human pathogenic bacteria [3].  For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria and the Gram-negative bacterium in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses.  Researchers concluded that “elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses.”   As mentioned earlier, bacterial infections, such as bacterial pneumonia, are serious complications when associated with the flu.

A 2016 study published in Nutrients showed that elderberry supplementation was able to reduce cold duration and symptoms in air travelers [7]. This randomized, double-blind placebo-controlled clinical trial of 312 economy class passengers traveling from Australia to an overseas destination investigated if elderberry extract has beneficial effects on health. Travelers using elderberry from 10 days before travel until four to five days after arrival overseas experienced, on average, a two-day shorter duration of their colds as well as a noticeable reduction in cold symptoms.

In summary, elderberries have shown antiviral activities in lab studies (in vitro). Clinical trials using elderberry extract have shown a reduction in symptoms and duration of cold and flu infections.  Elderberry is also antibacterial, potentially decreasing the occurrence of opportunistic bacterial infections during a flu illness, such as bacterial pneumonia.

Want to learn more about where to find elderberries, or how to make your own elderberry syrup?  Check out this article on the blog. 

REFERENCES

1. Lila, Mary Ann.  “Anthocyanins and Human Health: An In Vitro Investigative Approach.”  J Biomed Biotechnol. 2004 Dec 1; 2004(5): 306–313. doi: 10.1155/S111072430440401X. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1082894/
2. Roschek, B., et al. “Elderberry flavonoids bind to and prevent H1N1 infection in vitro. Phytochemistry.” 2009;70:1255–1261. doi: 10.1016/j.phytochem.2009.06.003. https://www.ncbi.nlm.nih.gov/pubmed/19682714
3. Krawitz, C., et al. “Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses.” BMC Complement. Altern. Med. 2011;11:182 doi: 10.1186/1472-6882-11-16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3056848/
4. Zakay-Rones, Z., et al. “Randomized Study of the Efficacy and Safety of Oral Elderberry Extract in the Treatment of Influenza A and B Virus Infections.” Journal of International Medical Research. April-01-2004; pp. 132 – 140. http://journals.sagepub.com/doi/pdf/10.1177/147323000403200205
5. Kong, F. “Pilot clinical study on a proprietary elderberry extract: Efficacy in addressing influenza symptoms.” Online J. Pharmacol. Pharmacokinet. 2009;5:32–43. https://pdfs.semanticscholar.org/367d/1c92716b6be462f26dbfe6c223863dc78464.pdf
6. Zakay-Rones, Z, et al. “Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B Panama.” J Altern Complement Med. 1995 Winter;1(4):361-9. https://www.ncbi.nlm.nih.gov/pubmed/9395631
7. Tiralongo E, et al. “Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial.” Nutrients. 2016 Mar 24;8(4):182. doi: 10.3390/nu8040182. https://www.ncbi.nlm.nih.gov/pubmed/27023596