They're not a buckthorn and they don't grow by the sea. Doesn't make much sense, right?
This sample tested was from Norway which interestingly enough, were significantly higher than those sourced from Denmark.
While they do have moderate antioxidant content, their most impressive benefit is their omega 7 content. An elusive fatty acid that benefits your skin.
You probably can't find the fresh berries but consider sea buckthorn oil.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH 2010