Elderberry: Health Benefits & Possible Side Effects, From MDs

Elderberries have gained a reputation for supporting the immune system, particularly during cold and flu seasons. However, in the wake of COVID-19, the commonly beloved fruit has received some conflicting reviews. 

To better understand the health benefits and the potential drawbacks of elderberries, mbg spoke with integrative medicine doctors and immunologists. Here's what they have to say about the supplement and how it may react with viruses.  

The elderberry fruit1 (sambucus nigra) is commonly found in North America and Europe and has been used medicinally for centuries, says integrative medicine doctor Alejandra Carrasco, M.D.

Elderberry flowers and leaves were traditionally used to manage inflammation, pain, and swelling. Today, the berry is most commonly found in supplement, syrup, or tea form to support the immune system2 and help fight cold and flu symptoms. 

Elderberry is often recommended during cold and flu season. Liquid extract from the berry has been shown to limit activity against pathogenic bacteria, influenza, and the common cold, Carrasco says. 

One study published in the Journal of Functional Food specifically looked at the influenza virus in vitro and found that elderberry extract3 "showed mild inhibitory effect at the early stages of the influenza virus cycle, with considerably stronger effect in the post-infection phase."

"In general, elderberries are an excellent source of antioxidants, which help to maintain a strong immune system," functional medicine doctor Tiffany Lester, M.D., tells mbg. "Especially against viruses." 

Elderberries are a good source of vitamins and minerals. While the nutritional values will vary by product, 1 cup of raw elderberries4 contains:

"Elderberries contain flavonoids, proanthocyanidins, anthocyanins, and phenolic acids, which protect against the oxidative stress caused by reactive oxygen species (ROS)," Carrasco says. Too much ROS has been linked to the development of many chronic and neurodegenerative diseases5. Therefore, adding these antioxidants to the diet may lower the risk of developing chronic illness. 

Elderberry should not be used in place of prescription medicines or other treatments. Anyone thinking about adding elderberry to their supplement routine should consider consulting a doctor.  

The bark, leaves, and root of the elderberry plants contain sambunigrin, which can release cyanide, Carrasco says. When ripe or cooked, however, the berries don't contain the potentially toxic substance. "If you are making your own syrup, make sure that you thoroughly cook the berries," Carrasco adds. 

When taking elderberry in gummy supplement or syrup form, Lester says to keep the added sugar content in mind. "Sugar in all forms is inflammatory, so I encourage people to look at the labels and choose the lowest added sugar content available," she says. 

Despite being known for immune-supporting benefits, some experts have raised concerns about the way elderberries react to the coronavirus. Elderberry activates inflammatory cytokines in the body, which, in the face of the cold and the flu, can be beneficial. However, when introduced to the COVID-19 virus, those cytokines may produce at a rapid and uncontrollable rate (called a cytokine storm2), integrative immunologist Heather Moday, M.D., explains. "It's rare but often fatal and can happen with other viruses and bacteria, too," she says. 

The research on this topic is still developing, and there's no conclusive evidence that elderberry creates a cytokine storm in all COVID-19 patients. To avoid any potential risks, Lester suggests taking other immune-supporting supplements, like vitamin C, vitamin D, quercetin, glutathione, and zinc.

In general, elderberry supplementation can be a safe and effective way to increase nutrient intake, antioxidants, and protect against cold and flu symptoms. However, if someone tests positive or shows symptoms of COVID-19, Moday says it should be avoided—just in case.