one cause that may show the truth of dark chocolate can grow micro-circulation in the skin. It can increased blood run to the outer layer of the derma and give the healthy oxygenation on your skin that require to protect skin.
One rationale may come from the fact that high-cocoa chocolate can increase micro-circulation in the skin itself. Increased blood flow to the topmost layers of the skin (those within only one millimeter of the surface) can provide the healthy oxygenation your skin needs to help protect itself.