Turmeric is traditionally used as a spice and coloring in foods. It is an important ingredient in curry and gives curry powder its characteristic yellow color. As a consequence of its intense yellow color, turmeric, or curcumin (food additive E100), is used as a food coloring (e.g. mustard). Turmeric contains the curcuminoids curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Recently, the health properties (neuroprotection, chemo‐, and cancer prevention) of curcuminoids have gained increasing attention. Curcuminoids induce endogenous antioxidant defense mechanisms in the organism and have anti‐inflammatory activity. Curcuminoids influence gene expression as well as epigenetic mechanisms. Synthetic curcumin analogues also exhibit biological activity. This Review describes the development of curcumin from a “traditional” spice and food coloring to a “modern” biological regulator.