Elderberry Extract for Influenza?

A Professor's Perspective on Current Events

Image of Professor Roy Benaroch. M.D.
By, Professor Roy Benaroch. M.D.

Could Elderberry Extract for Influenza Really Help? Dr. Roy Benaroch discusses this interesting, tasty, and possible “magic fix” for influenza.

The article originally premiered on The Pediatric Insider.

A Facebook pal posted about using an elderberry extract to treat flu – apparently, this stuff is flying off the shelves. Could it really help?

Illustration of the Influenza VirusIt’s certainly conceivable that a plant extract could have anti-viral or other health-promoting properties. After all, plants battle with viruses, bacteria, and other microorganisms all the time. We know that there are tons of “natural” compounds right there in the plants we eat that are themselves pesticides or antimicrobials (in fact, there’s far more pesticide in a plant than is ever sprayed on a plant. Cool, huh?) There’s a certain plausibility that says some plants or plant exacts could help prevent or treat infections. There have also been a small number of in vitro studies of elderberry – that is, studies in a test tube – that show some antimicrobial properties. And even one study in chimps!

But what we really want to know is whether elderberry can help fight flu in people. And to do that, we need a good study. A randomized controlled trial, to be precise, where some people with flu are given elderberry, and another group a placebo. And then let’s see how they do. Science!

Illustration of The Mechanics of The Influenza VirusIn fact, one such trial was done about 20 years ago, by a team of researchers from Israel and Scandinavia. 80 adults from age 18 to 54 (no children) were candidates for inclusion, all with typical flu symptoms during the 1999 flu season, recruited from one of four health centers in Norway. 60 people participated in the study (it’s unclear how the 80 was whittled down to 60.) Half of the 60 were given a standardized elderberry extracted called “Sambucol”, made in Israel; the other half were given a syrup said to be identical in taste, but lacking actual elderberry. Both groups were told to take a tablespoon of their syrup four times a day for 5 days. No attempt was made to see if patients could guess whether they were in the placebo or elderberry group.

Illustration of The Mechanics of The Influenza VirusThe patients judged how they felt on several scales of crumminess, rating their own aches and pains, degree of coughing, quality of sleep, and other measures each day. Their ratings at the beginning of the study were similar (which is good—that means the randomization didn’t put sicker people in unbalanced groups.) None of the patients had any important side effects.

Illustration of The Mechanics of The Influenza VirusThe results – you can take a look at them in figure 1 – were impressive. The elderberry-takers quickly had a huge improvement in symptoms and rated that they had almost no symptoms by day 4. Contrast with the placebo-takers, who really didn’t get back to feeling good until day 8. There are different ways to break down different symptoms in the text of the study, but the bottom line is that these authors found elderberry extract to be very effective at relieving the symptoms of flu.

Illustration of The Mechanics of The Influenza VirusI have some doubts. The results fail a kind of “sniff test” to me – they’re too good to be true. No one with flu has symptoms that disappear so quickly. And it shouldn’t have taken the control group 8 days to get better, even with no treatment at all. I wonder if the patients were truly blinded, or if they figured out their group assignment. I read a lot of studies, and these results show a huge effect size seldom seen with any intervention.

Image of the influenza pandemic timeline
The H1N1 Virus continues to mutate as it finds new hosts to infect

I also wonder what impact the funding source could have had – the study was funded by the maker of Sambucol, who also supplied the elderberry and placebo extracts. The study was performed in 1999 and published in 2004, and I cannot find any further human studies of any elderberry product to fight influenza since then.

This article is part of our Professor’s Perspective series—a place for experts to share their views and opinions on current events.

So there you have it – that’s the evidence. A single, small, industry-paid-for study showing a remarkably positive effect of elderberry in treating influenza in adults. Color me skeptical. But I’ll also say that I don’t know of any downside to elderberry – as far as I can tell, it’s safe, and some people even like the taste. And other than fluids and ibuprofen, I don’t know of anything else that has a big impact on treating influenza. Is it worth a try? Sure. Let me know how it goes.

For more with Dr. Benaroch, check out Medical School for Everyone on The Great Courses Plus!

1 Comment

  1. “No one with flu has symptoms that disappear so quickly.”

    When I get the flu, my symptoms last no longer than 3 days. One of my sons is the same. Our flu diagnoses were verified by a doctor. I must say that when a professional uses generalized statements like this, it concerns me.

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