For healthy skin, collagen is key: This naturally occurring protein keeps skin smooth and youthful, but our bodies produce less collagen as we get older. The result? Thinner skin, dryness, and more wrinkles.
Definition of BLACK BILE. : a humor of medieval physiology believed to be secreted by the kidneys or spleen and to cause melancholy. ADVERTISEMENT.1681. a humor of medieval physiology believed to be secreted by the kidneys or spleen and to cause melancholy. ADVERTISEMENT. 1681.
bile pigments, a group of substances that contribute to the colors of bile, which may range from a yellowish green to brown. A common bile pigment is bilirubin, which contains a reddish iron pigment derived from the breakdown of old red blood cells.