Dietary sugars stimulate fatty acid synthesis in adults.
The goal of this study was to determine the magnitude by which acute consumption of fructose in a morning bolus would stimulate lipogenesis (measured by infusion of 13C1-acetate and analysis by GC-MS) immediately and after a subsequent meal. Six healthy subjects [4 men and 2 women; aged (mean +/- SD) 28 +/- 8 y; BMI, 24.3 +/- 2.8 kg/m(2); and serum triacylglycerols (TG), 1.03 +/- 0.32 mmol/L] consumed carbohydrate boluses of sugars (85 g each) in a random and blinded order, followed by a standardized lunch 4 h later. Subjects completed a control test of glucose (100:0) and a mixture of 50:50 glucose:fructose and one of 25:75 (wt:wt). Following the morning boluses, serum glucose and insulin after 100:0 were greater than both other treatments (P < 0.05) and this pattern occurred again after lunch. In the morning, fractional lipogenesis was stimulated when subjects ingested fructose and peaked at 15.9 +/- 5.4% after the 50:50 treatment and at 16.9 +/- 5.2% after the 25:75 treatment, values that were greater than after the 100:0 treatment (7.8 +/- 5.7%; P < 0.02). When fructose was consumed, absolute lipogenesis was 2-fold greater than when it was absent (100:0). Postlunch, serum TG were 11-29% greater than 100:0 and TG-rich lipoprotein-TG concentrations were 76-200% greater after 50:50 and 25:75 were consumed (P < 0.05). The data demonstrate that an early stimulation of lipogenesis after fructose, consumed in a mixture of sugars, augments subsequent postprandial lipemia. The postlunch blood TG elevation was only partially due to carry-over from the morning. Acute intake of fructose stimulates lipogenesis and may create a metabolic milieu that enhances subsequent esterification of fatty acids flowing to the liver to elevate TG synthesis postprandially.
Parks
Elizabeth J
EJ
Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390-9052, USA. elizabeth.parks@utsouthwestern.edu
Skokan
Lauren E
LE
Timlin
Maureen T
MT
Dingfelder
Carlus S
CS
D000328:Adult; D001786:Blood Glucose; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000494:pharmacology; D005227:Fatty Acids / Q000096:biosynthesis*; D005260:Female; D005632:Fructose / Q000008:administration & dosage / Q000494:pharmacology*; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005227:Fatty Acids; D007328:Insulin; D014280:Triglycerides; D005632:Fructose; D005947:Glucose