Consumption of alpha-linolenic acid-enriched diacylglycerol induces increase in dietary fat oxidation compared with alpha-linolenic acid-enriched triacylglycerol: A randomized, double-blind trial

Fat metabolism is an important consideration in obesity. Alpha-linolenic acid-enriched diacylglycerol (ALA-DAG), which mainly occurs as ALA esterifies to 1,3-diacyl-sn-glycerol (1,3-DAG), has beneficial effects on fat metabolism and body weight compared with triacylglycerol (TAG). Moreover, compared with ALA-TAG, ALA-DAG enhances β-oxidation activity in the small intestine and liver in rodents. We hypothesized that ALA-DAG consumption may increase dietary fat oxidation compared with ALA-TAG in humans. To examine this hypothesis, we conducted a randomized double-blind cross-over trial in 17 normal and moderately obese men and women (BMI: 25.7±2.0 kg/m², mean±SD). Each participant was assigned to a 4-week intervention period with 2.5 g/day of ALA-DAG or ALA-TAG consumption, followed by a 4-week washout period between consumption of each diet. Dietary fat oxidation, assessed based on the ¹³CO₂ recovery rate in the breath, was significantly increased by ALA-DAG consumption compared with ALA-TAG consumption (17.0±4.5% and 14.1±5.9%, respectively, P<.05). In addition, ALA-DAG consumption significantly decreased the visceral fat area compared with ALA-TAG (102.9±51.9 cm² and 110.9±51.7 cm², respectively; P<.05). These results indicate that ALA-DAG consumption may be useful for preventing obesity.

Alpha Linolenic Acid-enriched Diacylglycerol Consumption Enhances Dietary Fat Oxidation in Healthy Subjects: A Randomized Double-blind Controlled Trial

Consumption of alpha linolenic acid-enriched diacylglycerol (ALA-DAG) reduces visceral fat area. In this study, we performed a randomized, placebo-controlled, double-blind, crossover intervention trial to investigate the effect of ALA-DAG on dietary fat oxidation in comparison with control triacylglycerol (TAG). Each subject (n=16) consumed either 2.5 g/d of ALA-DAG or TAG for 14-d, separated by a 21-d washout period. At the end of each consumption period, we assessed dietary fat oxidation. ALA-DAG consumption significantly enhanced dietary fat utilization as energy compared to TAG consumption.

Genotoxicity evaluation of alpha-linolenic acid-diacylglycerol oil

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We evaluated the genotoxicity of ALA-DAG oil using standard tests.

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Bacterial reverse mutation and in vitro/in vivo micronucleus tests were conducted.

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No genotoxicity was observed under the testing conditions.

The alpha-linolenic acid (ALA)-diacylglycerol (DAG) oil is an edible oil enriched with DAG (>80%) and ALA (>50%). Although DAG oil, which mainly consists of oleic and linoleic acids has no genotoxic concerns, the fatty acid composition could affect the chemical property of DAG. Therefore, the purpose of this study was to evaluate the genotoxicity of ALA-DAG oil using standard genotoxicity tests in accordance with the OECD guidelines. ALA-DAG oil showed negative results in the bacterial reverse mutation test (Ames test) and in vitro micronucleus test in cultured Chinese hamster lung cells with and without metabolic activation, and in the in vivo bone marrow micronucleus test in mice. Our results did not show any genotoxicity, suggesting that the fatty acid composition had no deleterious effects. We conclude that ALA-DAG oil had no genotoxicity concerns under the testing conditions.

Alpha Linolenic Acid-enriched Diacylglycerol Enhances Postprandial Fat Oxidation in Healthy Subjects: A Randomized Double-blind Controlled Trail

Alpha linolenic acid-enriched diacylglycerol (ALA-DAG) reduces visceral fat area and body fat in rodents and humans compared to conventional triacylglycerol (TAG). Although ALA-DAG increases dietary fat utilization as energy in rodents, its effects in humans are not known. The present study was a randomized, placebo-controlled, double-blind, crossover intervention trial performed to clarify the effect of ALA-DAG on postprandial energy metabolism in humans. Nineteen healthy subjects participated in this study, and postprandial energy metabolism was evaluated using indirect calorimetry followed by 14-d repeated pre-consumption of TAG (rapeseed oil) as a control or ALA-DAG. As a primary outcome, ALA-DAG induced significantly higher postprandial fat oxidation than TAG. As a secondary outcome, carbohydrate oxidation tended to be decreased. In addition, postprandial energy expenditure was significantly increased by ALA-DAG compared to TAG. These findings suggest that daily ALA-DAG consumption stimulates dietary fat utilization as energy after a meal, as well as greater diet induced thermogenesis in healthy humans. In conclusion, repeated consumption of ALA-DAG enhanced postprandial fat metabolism after a meal, which may partially explain its visceral fat area-reducing effect.