C O N T E N T SDescriptionFucose is a hexose sugar with the chemical formula C6H12O5. It is found on N-linked glycans on the mammalian and plant cell surface. DiscussionFucose is the H(o) antigen. Dietary fucose can be readily absorbed from the small intestine. In a study in healthy volunteers, oral administration of fucose at a dose of 50-100 mg/kg body weight (equivalent to 3.5-7.0 grams per 150-lb person) increased serum fucose concentrations, which reached a maximum of 110-210 ?mol/L after 60 minutes. Fucose was then cleared from the serum with a half-time of 100 minutes. After 24 hours, fucose in the serum was still greater than basal levels. In a study in rats, the serum half-life of fucose was 110-140 minutes; after 1 hour, about 39% of the oral dose appeared in the expired CO2, 13-24% was found in feces and gastrointestinal contents, and 0.3% was present in the serum. Absorbed fucose is extensively incorporated either directly or after metabolism into glycoproteins. Unabsorbed fucose is metabolized by intestinal bacteria. SafetySafety Fucose appears to be relatively safe when given repeatedly at high daily oral doses. For example, when fucose was given orally in the diet at daily doses of up to 492 mg/kg body weight (equivalent to >34 grams per 150-lb human) over a period of 277 days to treat the rare inherited disorder of leukocyte adhesion deficiency, no significant adverse effects were reported. The only remotely related oral toxicity studies in the scientific literature involved animals ingesting a diet composed of 20% fucose, an amount in extreme excess of any dietary dosage. In these studies, there was reversible reduced nerve conduction velocity and reduced collagen production in cultured cerebral microvessel endothelial cells obtained from fucose-fed animals. The relevance of these findings to a possible similar effect in humans is, however, completely unknown, especially based on the extremely high doses of fucose, the in vitro data, and metabolic differences in humans. Actually, several studies of ingested fucose have shown beneficial biological effects. For example, fucose is known to be an immune system modulator. It has also been shown to have therapeutic implications in treating or preventing respiratory tract infections and in inhibiting cancer growth and metastasis. In addition, fucose appears to have a beneficial role in neonatal health, since concentrations of fucose-containing glycoproteins in maternal urine have been found to increase markedly during the latter stages of pregnancy and during lactation. Moreover, none of these studies have reported significant toxicity from fucose treatment. Links |