Elderberry (Sambucus nigra) is the fruit of the European elder tree, which is native to Europe but naturalized in America. Parts of the tree have been used for hundreds of years as an alternative treatment for medical ailments. In the kitchen, cooks use the berries to flavor food and drink. The flowers and berries contain flavonoids, which have antioxidant and immunologic properties. (Still, do not take elderberry as treatment for a medical condition without first consulting a doctor.)
Elderberry extract has been used to treat colds and influenza, and as an expectorant, emetic or diuretic. According to studies cited by Medline Plus (part of the National Institutes of Health), "Elderberry juice may improve flu-like symptoms, such as fever, fatigue, headache, sore throat, cough and aches, in less time than it normally takes to get over the flu." Early reports also show that it may decrease the concentrations of serum cholesterol and increase the stability of low-density LDL ("bad") cholesterol.
Elderberry extract is used to make the licorice-flavored liqueur Sambuca and elderberry wine; to add flavor and color to Red Windsor Cheese; and to heighten the flavor of elderberry pie, jam and syrup. Fresh elderberries tend to be somewhat bland-tasting, but they are very rich in vitamin C.
If you are allergic to plants in the Caprifoliaceae (honeysuckle) family, avoid elderberry extract. There have been reports of gastrointestinal problems after drinking elderberry juice, and it's important to know that the berries can cause nausea or cyanide toxicity if not cooked properly. To eat them safely, bring the berries to a boil for jam, juice or syrup; cook until heated through when using in a pie.