The Forgotten Amino Acid in Slow-Cooked Foods

A building block of protein, glycine was once obtained naturally from a diet high in slow-cooked connective tissues, bone broth, and marrow.

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The expensive protein powders on the market offer an amino acid your great-grandmother got for free—from the parts of the animal nobody wanted.

Bone broth simmered for hours, fall-off-the-bone lamb shank, rich slow-cooked meats, buttery bone marrow spread onto toast—these foods weren’t delicacies; they were once regular meals. Without knowing it, generations of home cooks were providing an overlooked nutrient—glycine.