Review of the toxicologic properties of medium-chain triglycerides

Medium chain triglycerides (MCTs) are a family of triglycerides, containing predominantly, caprylic (Cs) and capric (Clo) fatty acids with lesser amou nts of caproic (C-6) and lauric (C-12) fatty acids. MCTs are widely used fo r parenteral nutrition in individuals requiring supplemental nutrition and are being more widely used in foods, drugs and cosmetics. MCTs are essentia lly non-toxic in acute toxicity tests conducted in several species of anima ls. In ocular and dermal irritation testing MCTs exhibit virtually no poten tial as ocular or dermal irritants, even with prolonged eye or skin exposur e. MCTs exhibit no capacity for induction of hypersensitivity. Ninety-day t oxicity tests did not result in notable toxicity, whether the product was a dministered in the diet up to 9375 mg/kg body weight/day or by intramuscula r (im) injection (up to 0.5 ml/kg/day, rabbits). There was no evidence that intravenous (iv) or dietary administration of MCTs adversely affected the reproductive performance of rats or resulted in maternal toxicity, foetal t oxicity or teratogenic effects at doses up to 4.28 g/kg body weight/day (iv ) or 12,500 mg/kg body weight/day (dietary), There was no evidence that die tary administration of MCTs adversely affected the reproductive performance of pigs or resulted in maternal toxicity, foetal toxicity or teratogenic e ffects at doses up to 4000 mg/kg body weight/day in the diet. In rabbits, f ollowing iv administration, the maternal and foetal no-observed-adverse-eff ect levels (NOAELs) were between 1.0 and 4.28 g/kg body weight/ day. A 2-ye ar study in rats, conducted with a closely related compound (tricaprylin, a triglyceride with Cs fatty acids), provided no evidence of a carcinogenic effect when the material was administered by oral gavage at levels up to 10 ml/kg (9.54 g/kg) per day. Although tricaprylin was found to be positive i n one of five strains of Salmonella typhimurium in the presence of metaboli c activation in an Ames mutagenicity assay, the results of the carcinogenic ity test with tricaprylin and mutagenicity tests with caprylic acid indicat e that MCTs do not have the potential to be carcinogenic or mutagenic. The safety of human dietary consumption of MCTs, up to levels of 1 g/kg, has be en confirmed in several clinical trials. (C) 2000 Elsevier Science Ltd. All rights reserved.