Author
BENDSEN, NATHALIE - University Of Copenhagen | |
CHABANOVA, ELIZAVETA - Copenhagen University | |
THOMSEN, HENRIK - University Of Copenhagen | |
LARSEN, THOMAS - University Of Copenhagen | |
Newman, John | |
STENDER, STEEN - Copenhagen University | |
DYERBERG, JORN - University Of Copenhagen | |
HAUGAARD, STEEN - Copenhagen University | |
ASTRUP, ARNE - University Of Copenhagen |
Submitted to: Nutrition and Diabetes
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/1/2010 Publication Date: 1/15/2010 Citation: Bendsen, N.T., Chabanova, E., Thomsen, H.S., Larsen, T.M., Newman, J.W., Stender, S., Dyerberg, J., Haugaard, S.B., Astrup, A. 2010. Trans fatty acids adversely affect blood lipids but not intra-abdominal and liver fat deposition - a randomized trial in overweight postmenopausal women. Nutrition and Diabetes. 1:e4; 10.1038. Interpretive Summary: Intake of industrially produced trans fatty acids (TFA) is, according to observational studies, associated with an increased risk of cardiovascular disease, but the causal mechanisms have not been fully elucidated. Besides inducing changes in blood lipid profiles with adverse health consequences, dyslipidemia, TFA intake is suspected to promote the deposition of fat inside the abdominal cavity and liver. In this study, we examined the effect of a high intake of TFA as part of an isocaloric diet on whole-body, abdominal and hepatic fat deposition, as well as blood lipids, in postmenopausal women. In a 16-wk double-blind parallel intervention study, 52 healthy overweight postmenopausal women were randomized to receive either partially hydrogenated soybean oil providing 15.7 g/d of TFA or a control oil with mainly oleic and palmitic acid and <0.2 g/d of TFA. Before and after the intervention, body composition, abdominal fat, and liver fat was assessed. Compared to the control oil, TFA intake decreased plasma HDL-cholesterol by 10%, increased LDL-cholesterol by 18%, and increased the LDL/HDL-cholesterol ratio by ~3-fold [(0.22; 0.60); P < 0.001]. While TFA tended to increase body fat [0.46 (-0.20; 1.17) kg; P = 0.16] and waist circumference [1.1 (-0.1; 2.4) cm; P = 0.08] more than the control fat, neither abdominal nor liver fat deposition was affected by TFA intake. In conclusion, our study suggests that the adverse effect of dietary TFA on cardiovascular disease risk involves induction of dyslipidemia, and perhaps body fat, whereas a weight gain-independent accumulation of fat in sites in the body unaccustomed to fat deposition could not be identified as a contributing factor during short-term intake. Technical Abstract: Intake of industrially produced trans fatty acids (TFA) is, according to observational studies, associated with an increased risk of cardiovascular disease, but the causal mechanisms have not been fully elucidated. Besides inducing dyslipidemia, TFA intake is suspected of promoting abdominal and liver fat deposition. We examined the effect of a high intake of TFA as part of an isocaloric diet on whole-body, abdominal and hepatic fat deposition and blood lipids in postmenopausal women. In a 16-wk double-blind parallel intervention study 52 healthy overweight postmenopausal women were randomized to receive either partially hydrogenated soybean oil providing 15.7 g/d of TFA or a control oil with mainly oleic and palmitic acid. Before and after the intervention, body composition was assessed by dual-energy x-ray absorptiometry, abdominal fat by magnetic resonance (MR) imaging, and liver fat by 1H MR spectroscopy. Compared to the control fat TFA intake decreased plasma HDL-cholesterol by 10%, increased LDL-cholesterol by 18%, and resulted in an increased LDL/HDL-cholesterol ratio [baseline adjusted mean (95%CI) difference between diet groups 0.41 (0.22; 0.60); P<0.001]. TFA tended to increase body fat [0.46 (-0.20; 1.17) kg; P = 0.16] and waist circumference [1.1 (-0.1; 2.4) cm; P=0.08] more than the control fat, whereas neither abdominal nor liver fat deposition was affected by TFA. In conclusion, our study suggests that the adverse effect of dietary TFA on cardiovascular disease risk involves induction of dyslipidemia, and perhaps body fat, whereas weight gain-independent accumulation of ectopic fat could not be identified as a contributory factor during short-term intake. |