Recent developments in molecular biology have led to the recognition of food-derived lipids and their metabolites, including cholesterol, fatty acids, bile acids and litocholic acids, as ligands of each corresponding nuclear receptor and regulators of key physiological events. Intake of diacylglycerol, which comprises up to 10% of glycerides in plant-derived edible fats and oils and contains 70% of the unusual 1,3-species, has been shown to affect lipid and glucose metabolism. Effects include lowering of plasma triacylglycerol, decreasing postprandial hyperlipidemia and hemoglobin A1c, increasing energy expenditure, and reducing diet-induced obesity compared with triacylglycerol, which has a similar fatty acid composition. This review summarizes recent research into the metabolic effects and possible mechanisms of diacylglycerol outcome.
Reacylation to triacylglycerol in small intestinal cells was found to be slower with diacylglycerol feeding than triacylglycerol feeding. Expression of mRNA of β-oxidative and uncoupling proteins 2 was also increased in liver and/or intestinal cells on feeding diacylglycerol compared with triacylglycerol. Because the energy value and absorptive and digestive properties are similar, the different effects of diacylglycerol compared with triacylglycerol are due to their structural differences.
The stimulation of enzyme activities responsible for β-oxidation and regulation of lipid metabolism-related gene expression in the small intestine may contribute to reduced postprandial hyperlipidemia as well as to increased energy expenditure, which result in suppression of diet-induced obesity. Further analysis is required to elucidate the chemical and biological properties of diacylglycerol, especially of 1,3-diacylglycerol, on digestion, absorption and metabolic processes that may provide new insights for managing a lifestyle-related chronic disease such as the metabolic syndrome.
Department of General Medicine, Kashiwa Hospital, Jikei University School of Medicine, Chiba, Japan
Correspondence to Norio Tada MD PhD FAHA, Professor, Department of General Medicine, Kashiwa Hospital, Jikei University School of Medicine, 163-1 Kashiwashita Kashiwa, Chiba 277-8567, Japan Tel: +81 4 7164 1111 ext 3260; fax: +81 4 7164 1126; e-mail: email@example.com