The berries and flower of American elder offer similar flavor and health benefits and can be used in the same ways as European elder.
American elder varieties are genetically almost identical to European elder, but American varieties are more cold hardy and tend to grow more vigorously in our climates. (2) American elder typically grow as multi-stemmed bushes while European varieties are usually somewhat taller shrubby trees.
Another difference — European elderberries contain significant levels of cyanogenic glycosides, a family of chemicals that can be converted into cyanide, a hazardous chemical. European elderberries must be heated or otherwise processed to deactivate these glycosides. American elderberries (Sambucus canadensis) have low levels of glycosides — lower than commercial apple juice. The berries and juice are safe to consume without special treatment according to peer-reviewed, published research by the University of Missouri. (3,4)
“…Taking all of this information into consideration, my personal conclusion is that elderberries are as safe to consume as apples, with or without heating….” (5)
That said, consuming fresh berries of any kind can cause digestive upset in some people. Consume small amounts of fresh berries or juice until you know how your body reacts.
References:
(1) Wikipedia. Sambucus. Downloaded 16 February 2020 from en.wikipedia.org/w/index.php?title=Sambucus&oldid=933640739
(2) Observations from Carandale Farm, Univ of Wisconsin. Uncommon Fruit: European elderberry. Downloaded 20 February 2020 from uncommonfruit.cias.wisc.edu/european-elderberry/
(3) University of Missouri Extension Service staff. Unpublished results presented at the 2019 Comprehensive Elderberry Workshop hosted by River Hills Harvest. Jefferson City, MO, 14-15 June 2019. Powerpoint slides from this talk downloaded 19 March 2020 from https://www.greatplainsgrowersconference.org/uploads/2/9/1/4/29140369/elderberry_cyanide_st._joe_january_2019.pdf
(4) Appenteng MK, Krueger R, Johnson MC, Ingold H, Bell R, Thomas AL, Greenlief CM. Cyanogenic Glycoside Analysis in American Elderberry. Molecules. 2021 Mar 4;26(5):1384. doi: 10.3390/molecules26051384. PMID: 33806603; PMCID: PMC7961730. Abstract downloaded 9 February 2022 from https://pubmed.ncbi.nlm.nih.gov/33806603/
(5) Rebekah Bailey. Elderberry Toxicity. The Essential Herbal magazine, Nov/Dec 2019 issue. Republished online in its entirety in a 15 March 2020 blog post by Tina Sams, editor and publisher of The Essential Herbal. Downloaded 16 March 2020 from https://theessentialherbal.blogspot.com/2020/03/elderberry-new-research.html