Sialic acid is a family of sugars on cell-surface glycoproteins and glycolipids involved in cell recognition, signaling, and immune responses. It supports brain development and cognition (notably in infant nutrition), modulates pathogen interactions, and contributes to inflammation. Clinically, sialic-acid patterns serve as biomarkers for infections, inflammatory conditions and cancers, and it’s studied for therapeutic and nutritional applications.

Sialic acid is a terminal sugar on skin glycoproteins and glycolipids that supports hydration, barrier function, and cell signaling. It helps retain moisture, stabilizes extracellular matrix components like hyaluronic acid, promotes wound repair, and reduces inflammation. By supporting collagen and elastin interactions and defending against microbial attachment, sialic acid contributes to improved firmness, elasticity, and a smoother, more resilient complexion.

Another name for sialic acid is N‑acetylneuraminic acid (commonly abbreviated Neu5Ac or NANA). Sialic acids are a family of nine‑carbon acidic sugars found on cell-surface glycoproteins and glycolipids; N‑acetylneuraminic acid is the predominant form in humans and is often referred to simply as sialic acid. It plays key roles in cell signaling, pathogen recognition and immune modulation.

Foods high in sialic acid include mammalian milks—especially human colostrum and cow’s milk—and dairy products (yogurt, cheese). Eggs (particularly yolks), and animal tissues such as organ meats and muscle meats (beef, pork, poultry) and many fish and shellfish also contain sialic acids. Plant foods are generally low in sialic acid.

Sialic acids are terminal sugars on cell-surface glycoproteins and glycolipids that tend to change or decline with age. Reduced sialylation disrupts cell–cell signaling, promotes inflammation and immune dysregulation, and impairs neuronal plasticity and synaptic function. These effects contribute to tissue dysfunction and cognitive decline; modifying sialylation is being studied as a potential way to influence aging and related diseases.

Sialic acids are terminal sugars on cell-surface glycans that shape cell–cell recognition and immune responses. Altered sialylation promotes infection (many pathogens bind or cleave sialic acids), helps tumors evade immunity and increases metastasis, and modulates complement activity and inflammation. Genetic defects or excess sialylation cause neurological, storage, and inflammatory disorders. Targeting sialic-acid pathways is a therapeutic focus.