What does science say about the ingredients in functional beverages?

Functional beverages -- or drinks promoted as offering mental or physical benefits beyond hydration -- are growing in popularity around the world. Hundreds of companies have jumped into the market, hoping to get some buzz with trendy and sometimes unfamiliar ingredients.

What does science say about the ingredients in functional beverages?
Functional beverages -- or drinks promoted as offering mental or physical benefits beyond hydration -- are growing in popularity around the world. Hundreds of companies have jumped into the market, hoping to get some buzz with trendy and sometimes unfamiliar ingredients.