Pliny the Elder was a first century Roman author and naturalist. One of his most famous sayings is: "Truth comes out in wine."

Did he know about elderberry wine? Being a naturalist (and Roman), there's a good chance he did. After all, the health benefits of elderberry syrup for treating the symptoms of the flu have been anecdotally cited since before his time.

But it's only in the last 20 years that the medicinal properties of the elderberry have been scientifically documented.

• A small study published in 1998 showed that 93 percent of flu patients given elderberry syrup (Sambucol) were completely symptom-free within two days, while those taking a placebo recovered in about six days.

• Another controlled study from 1999-2000 in Norway reported that flu patients taking three teaspoons of elderberry syrup four times a day saw their symptoms improve four days earlier than others who took a placebo.

• And a randomized, double-blind trial in 2009 found that 48 hours after flu sufferers took elderberry extract, 28 percent of them were devoid of all flu symptoms and 60 percent showed some symptom relief. Not a single patient in the placebo control group showed any relief.

Elderberries are more bitter than blackberries or raspberries, which is why they're distilled into wines or baked in pies in combination with other berries.

But the concentrated syrup is what you want if you have flu symptoms. As the American Nutrition Association states, "Elderberry extract seems to offer an efficient, safe and cost-effective treatment for influenza."