Effect of trans-fatty acid intake on insulin sensitivity and intramuscular lipids--a randomized trial in overweight postmenopausal women. A high-trans fatty acid diet and insulin sensitivity in young healthy women. Intake of a Diet High in Trans Monounsaturated Fatty Acids or Saturated Fatty Acids: Effects on postprandial insulinemia and glycemia in obese patients with NIDDM Dairy and industrial sources of trans fat do not impair peripheral insulin sensitivity in overweight women. Study of the effect of trans fatty acids from ruminants on blood lipids and other risk factors for cardiovascular disease. Effects of trans- and n-3 unsaturated fatty acids on cardiovascular risk markers in healthy males. An 8 weeks dietary intervention study Beneficial effects of long-chain n-3 fatty acids included in an energy-restricted diet on insulin resistance in overweight and obese European young adults Prospective association of fatty acids in the de novo lipogenesis pathway with risk of type 2 diabetes: the Cardiovascular Health Study. Serum pentadecanoic acid (15:0), a short-term marker of dairy food intake, is inversely associated with incident type 2 diabetes and its underlying disorders. Dietary Monounsaturated Fatty Acids but not Saturated Fatty Acids Preserve the Insulin Signaling Pathway via IRS-1/PI3K in Rat Skeletal Muscle Diet-induced change in fatty acid composition of plasma triacylglycerols is not associated with change in glucagon-like peptide 1 or insulin sensitivity in people with type 2 diabetes. Effects of meals rich in either monounsaturated or saturated fat on lipid concentrations and on insulin secretion and action in subjects with high fasting triglyceride concentrations. Chronic dietary fat intake modifies the postprandial response of hemostatic markers to a single fatty test meal. Dietary fat intake and risk of type 2 diabetes in women. Increased n-6 polyunsaturated fatty acids do not attenuate the effects of long-chain n-3 polyunsaturated fatty acids on insulin sensitivity or triacylglycerol reduction in Indian Asians. Adverse effects on insulin secretion of replacing saturated fat with refined carbohydrate but not with monounsaturated fat: A randomized controlled trial in centrally obese subjects. Dietary fatty acids affect plasma markers of inflammation in healthy men fed controlled diets: a randomized crossover study.
Intake of industrially produced trans-fatty acids ( TFA ) has been linked to increased risk of type 2 diabetes mellitus in observational studies . We investigated the causality of this association by examining if a high intake of TFA impairs measures of glucose homeostasis and induces intramuscular lipid deposition in abdominally obese women . In a double-blind , parallel dietary intervention study , 52 healthy but overweight postmenopausal women were r and omized to receive either partially hydrogenated soybean oil ( 15 g/d TFA ) or a control oil ( mainly oleic and palmitic acid ) for 16 weeks . Three markers of glucose homeostasis and 4 markers of lipolysis were derived from glucose , insulin , C-peptide , nonesterified fatty acid , and glycerol concentrations during a 3-hour frequent sampling oral glucose tolerance test . Intramuscular lipids were assessed by magnetic resonance spectroscopy . Forty-nine women completed the  study .  Insulin sensitivity ( assessed by ISI(composite ) ) , β-cell function ( the disposition index ) , and the metabolic clearance rate of insulin were not significantly affected by the dietary intervention . Neither was the ability of insulin to suppress plasma nonesterified fatty acid and glycerol during oral glucose ingestion nor the intramuscular lipid deposition . In conclusion , high TFA intake did not affect glucose metabolism over 16 weeks in postmenopausal overweight women . A study population with a stronger predisposition to insulin resistance and /or a longer duration of exposure may be required for insulin sensitivity to be affected by intake of industrial TFA Epidemiological and experimental studies suggest that a diet rich in saturated fat affects insulin sensitivity . Monoenes and dienes that have an usaturated bond with the trans configuration ( trans fatty acids ) resemble saturated fatty acids with respect to structure , but no published data are available on the effect of trans fatty acids on insulin sensitivity . Therefore , the effects of diets high in trans fatty acids ( TFA diet ) and oleic acid ( monounsaturated fat [ MUFA ] diet ) on glucose and lipid metabolism were studied in 14 healthy women . Subjects consumed both experimental diets for 4 weeks according to a r and omized crossover study design . Both experimental diet periods were preceded by consumption of a st and ardized baseline diet for 2 weeks . The diets provided 36.6 % to 37.9 % of energy ( E% ) as fat . In the TFA diet , there was 5.1 E% trans fatty acids , and in the MUFA diet , 5.2 E% oleic acid , substituted for saturated fatty acids in the baseline diet . A frequently sample d intravenous glucose tolerance test ( FSIGT ) was performed at the end of the experimental diet periods . Glucose effectiveness ( S(G ) ) and the insulin sensitivity index ( S(I ) ) did not differ after the two experimental diet periods . There was also no difference in the acute insulin response between the diets . The total cholesterol to high-density lipoprotein ( HDL ) cholesterol ratio and serum total triglyceride , HDL , and low-density lipoprotein ( LDL ) triglyceride and apolipoprotein B ( apoB ) concentrations were higher ( P < .05 ) after the TFA diet . In conclusion , in young healthy women , the TFA diet result ed in a higher total/HDL cholesterol ratio and an elevation in triglyceride and apo B concentrations but had no effect on glucose and insulin metabolism compared with the MUFA diet OBJECTIVE High intake of trans fatty acids and saturated fatty acids ( SFAs ) is known to increase the risk of coronary heart disease . We studied the effects of diets enriched in various fatty acids on postpr and ial insulinemia and fasting serum levels of lipids and lipoproteins in obese patients with NIDDM . RESEARCH DESIGN AND METHODS Sixteen obese NIDDM patients were studied in a free-living outpatient regimen . After a run-in period , the patients received three different isocaloric diets for 6 weeks using a r and omized crossover design . The patients were instructed to keep the energy intake from carbohydrate and protein constant at 50 and 20 E% ( percent of energy intake ) , respectively , on all three diets . The fat composition of the diets differed : saturated fat ( SAT ) diet ( 20 E% SFAs , 5 E% polyunsaturated fatty acids [ PUFAs ] , and 5 E% monounsaturated fatty acids [ MUFAs ] ) versus cis monounsaturated fatty acid ( CMUFA ) diet ( 20 E% cis-MUFAs , 5 E% PUFAs , and 5 E% SFAs ) versus trans monounsaturated fatty acid ( TMUFA ) diet ( 20 E% trans-MUFAs , 5 E% PUFAs , and 5 E% SFAs ) . Fasting serum levels of lipids and lipoproteins were measured at baseline and in the fasting state before meal tolerance tests at the end of each study period . Insulin secretion was assessed from incremental serum insulin and C-peptide responses during the meal tests . RESULTS BMI , waist-to-hip ratio , and glycemic control remained stable throughout the study . After meal stimulation , postpr and ial glycemic responses were similar on all diets ; however , serum insulin and C-peptide responses were greater following the TMUFA and SAT diets than following the baseline or CMUFA diets ( P < 0.05 ) . No statistical difference was found in fasting levels of serum lipids ( total cholesterol , triglyceride , phospholipid , and nonesterified fatty acids ) or lipoproteins of HDL cholesterol , VLDL cholesterol , LDL cholesterol , and apolipoprotein B between diets . CONCLUSIONS In the presence of unchanged glycemia , both dietary trans fatty acids and SFAs induce an increase in postpr and ial insulinemia in obese patients with NIDDM BACKGROUND The 2 major dietary sources of trans fatty acids ( TFAs ) are partially hydrogenated oils and ruminant-derived products . Epidemiologic data suggest that chronic consumption of industrial sources of TFAs could be damaging to insulin sensitivity , but intervention studies on this issue have remained inconclusive . OBJECTIVE The trial was design ed to compare the effects of dairy compared with industrial sources of TFAs on insulin sensitivity in overweight women . DESIGN Sixty-three healthy women with abdominal obesity [ waist circumference > 88 cm and a body mass index ( in kg/m(2 ) ) > 28 ] were recruited . After a run-in period , the volunteers were r and omly assigned to consume 1 of 3 four-week diets : 60 g low-TFA lipids/d ( 0.54 g/d ; n = 21 ) , ruminant TFA-rich lipids ( 4.86 g/d ; n = 21 ) , or industrial TFA-rich lipids ( 5.58 g/d ; n = 21 ) . Changes in peripheral insulin sensitivity were assessed by using hyperinsulinemic-euglycemic clamps . RESULTS After the intervention period , fasting glycemia and insulinemia and insulin sensitivity were not significantly modified in either group ( P > 0.05 ) . CONCLUSIONS These data indicate that consumption of dairy- and industrial- source TFAs for 4 wk at nutritional levels do not impair peripheral insulin sensitivity in insulin-resistant women . Our study may not preassess the effects of TFAs in normal insulin-sensitive individuals . This trial was registered at Clinical Trials.gov as NCT00617435 BACKGROUND The intake of trans fatty acids ( TFA ) from industrially hydrogenated vegetable oils ( iTFA ) is known to have a deleterious effect on cardiovascular health , the effects of TFA from ruminants ( rTFA ) are virtually unknown . OBJECTIVE The purpose of the present study was to compare the effects of rTFA and iTFA on plasma LDL concentrations and other cardiovascular disease risk factors in healthy subjects . DESIGN In a double-blind , r and omized crossover controlled study , 38 healthy men were fed each of 4 experimental isoenergetic diets lasting 4 wk each . The 4 diets were high in rTFA ( 10.2 g/2500 kcal ) , moderate in rTFA ( 4.2 g/2500 kcal ) , high in iTFA ( 10.2 g/2500 kcal ) , and low in TFA from any source ( 2.2 g/2500 kcal ) ( control diet ) . RESULTS Plasma LDL-cholesterol concentrations were significantly higher after the high- rTFA diet than after the control ( P = 0.03 ) or the moderate- rTFA ( P = 0.002 ) diet . Plasma LDL-cholesterol concentrations also were significantly ( P = 0.02 ) higher after the iTFA diet than after the moderate-rTFA diet . Plasma HDL-cholesterol concentrations were significantly ( P = 0.02 ) lower after the high-rTFA diet than after the moderate-rTFA diet . Finally , all risk factors were comparable between the control and the moderate-rTFA diets . CONCLUSIONS These results suggest that , whereas a high dietary intake of TFA from ruminants may adversely affect cholesterol homeostasis , moderate intakes of rTFA that are well above the upper limit of current human consumption have neutral effects on plasma lipids and other cardiovascular disease risk factors Background : Studies of long-term intake of industrially produced trans fatty acids ( TFA ) and n-3 polyunsaturated fatty acids ( PUFA ) suggest opposite effects on cardiovascular disease risk . Common mechanisms of action are probable . Objective : To examine the effects on cardiovascular risk markers of dietary enrichment with TFA or n-3 PUFA . Design : R and omized , double-blind , parallel intervention trial . Setting : Department of Human Nutrition , The Royal Veterinary and Agricultural University . Subjects : In all , 87 healthy males included , 79 completed . Intervention : Subjects were r and omly assigned to 8 weeks of a daily intake of 33 g of experimental fats from either partially hydrogenated soy oil containing 20 g of TFA , 12 g of fish oil with approximately 4 g of n-3 PUFA and 21 g of control fat , or 33 g of control fat . The experimental fats were incorporated into bakery products .  Plasma lipids , blood pressure , heart rate variability ( HRV ) , arterial dilatory capacity , compliance , and distensibility were recorded before and after intervention and at follow-up 12 weeks after the intervention . Results : High-density lipoprotein cholesterol ( HDL-C ) decreased in the TFA group and triglycerides and mean arterial blood pressure decreased in the n-3 PUFA group compared to the control group . HRV , arterial dilatory capacity , compliance , and distensibility were unchanged . Conclusion : The results indicate that the association between coronary heart disease risk and intake of TFA and n-3 PUFA relates only modestly to changes in traditional risk markers . Sponsorship : Danish Medical Research Council ( Grant no. 22 - 01 - 0390 ) , Center of Advanced Food Research ( Copenhagen , Denmark ) ( Grant no. KVL-R-2001 - 107 ) , the Danish Heart Association ( Grant no. 99 - 2 - 3 - 45 - 22748 ) , Novozymes ( Bagsvaerd , Denmark ) , Aarhus Olie ( Aarhus , Denmark ) , and from private sources . The experimental fats were provided by Pronova Biocare ( Aalesund , Norway ) and Aarhus Olie ( Aarhus , Denmark ) Abstract Aims /hypothesisEpidemiological research indicates that long-chain n-3 polyunsaturated fatty acids ( LC n-3 PUFA ) improve insulin resistance . The aim of this study was to investigate the effects of seafood consumption on insulin resistance in overweight participants during energy restriction . Methods In this 8 week dietary intervention , 324 participants ( 20–40 years , BMI 27.5–32.5 kg/m2 , from Icel and , Spain and Irel and ) were r and omised by computer to one of four energy-restricted diets ( −30E% ) of identical macronutrient composition but different LC n-3 PUFA content : control ( n = 80 ; no seafood ; single-blinded ) ; lean fish ( n = 80 ; 150 g cod , three times/week ) ; fatty fish ( n = 84 ; 150 g salmon , three times/week ) ; ( 4 ) fish oil ( n = 80 ; daily docosahexaenoic/eicosapentaenoic acid capsules , no other seafood ; single-blinded  ) . Fasting glucose , insulin , adiponectin , plasma triacylglycerol and fatty acids in erythrocyte membrane were measured at baseline and endpoint . Insulin resistance was calculated using the homeostasis model assessment of insulin resistance ( HOMA-IR ) . Linear models with fixed effects and covariates were used to investigate the effects of seafood consumption on fasting insulin and HOMA-IR at endpoint in comparison with the control group . Results Of the participants , 278 ( 86 % ) completed the intervention .  Fish oil intake was a significant predictor of fasting insulin and insulin resistance after 8 weeks , and this finding remained significant even after including weight loss , triacylglycerol reduction , increased LC n-3 PUFA in membranes or adiponectin changes as covariates in the statistical analysis . Weight loss was also a significant predictor of improvements . Conclusions /interpretationLC n-3 PUFA consumption during energy reduction exerts positive effects on insulin resistance in young overweight individuals , independently from changes in body weight , triacylglycerol , erythrocyte membrane or adiponectin . Trial registration : Clinical Trials.gov NCT00315770 . Funding : The YOUNG study is part of the SEAFOODplus Integrated Project , which is funded by the EC through the 6th Framework Programme Contract No. FOOD-CT-2004 - 506359 BACKGROUND Experimental evidence suggests that hepatic de novo lipogenesis ( DNL ) affects insulin homeostasis via synthesis of saturated fatty acids ( SFAs ) and monounsaturated fatty acids ( MUFAs ) . Few prospect i ve studies have used fatty acid biomarkers to assess associations with  type 2 diabetes . OBJECTIVES We investigated associations of major circulating SFAs [ palmitic acid ( 16:0 ) and stearic acid ( 18:0 ) ] and MUFA [ oleic acid ( 18:1n-9 ) ] in the DNL pathway with metabolic risk factors and incident diabetes in community-based older U.S. adults in the Cardiovascular Health Study . We secondarily assessed other DNL fatty acid biomarkers [ myristic acid ( 14:0 ) , palmitoleic acid ( 16:1n-7 ) , 7-hexadecenoic acid ( 16:1n-9 ) , and vaccenic acid ( 18:1n-7 ) ] and estimated dietary SFAs and MUFAs . DESIGN In 3004 participants free of diabetes , plasma phospholipid fatty acids were measured in 1992 , and incident diabetes was identified by medication use and blood glucose . Usual diets were assessed by using repeated food-frequency question naires . Multivariable linear and Cox regression were used to assess associations with metabolic risk factors and incident diabetes , respectively . RESULTS At baseline , circulating palmitic acid and stearic acid were positively associated with adiposity , triglycerides , inflammation biomarkers , and insulin resistance ( P-trend < 0.01 each ) , whereas oleic acid showed generally beneficial associations ( P-trend < 0.001 each ) . During 30,763 person-years , 297 incident diabetes cases occurred . With adjustment for demographics and lifestyle , palmitic acid ( extreme-quintile HR : 1.89 ; 95 % CI : 1.27 , 2.83 ; P-trend = 0.001 ) and stearic acid ( HR : 1.62 ; 95 % CI : 1.09 , 2.41 ; P-trend = 0.006 ) were associated with higher diabetes risk , whereas oleic acid was not significantly associated . In secondary analyses , vaccenic acid was inversely associated with diabetes ( HR : 0.56 ; 95 % CI : 0.38 , 0.83 ; P-trend = 0.005 ) . Other fatty acid biomarkers and estimated dietary SFAs or MUFAs were not significantly associated with incident diabetes . CONCLUSIONS In this large prospect i ve cohort , circulating palmitic acid and stearic acid were associated with higher diabetes risk , and vaccenic acid was associated with lower diabetes risk . These results indicate a need for additional investigation of biological mechanisms linking specific fatty acids in the DNL pathway to the pathogenesis of diabetes BACKGROUND Growing evidence suggests that dairy consumption is associated with lower  type 2 diabetes risk .  However , observational studies have reported inconsistent results , and few have examined dairy 's association with the underlying disorders of insulin resistance and β-cell dysfunction . OBJECTIVE We investigated the association of the dairy fatty acid biomarkers pentadecanoic acid ( 15:0 ) and trans-palmitoleic acid ( trans 16:1n-7 ) with type 2 diabetes traits by evaluating 1 ) prospect i ve associations with incident diabetes after 5 y of follow-up and 2 ) cross-sectional associations with directly measured insulin resistance and β-cell dysfunction . DESIGN The study analyzed 659 adults without diabetes at baseline from the triethnic multicenter Insulin Resistance Atherosclerosis Study ( IRAS ) .  Diabetes status was assessed by using oral-glucose-tolerance tests . Frequently sample d intravenous-glucose-tolerance tests measured insulin sensitivity ( SI ) and β-cell function [ disposition index ( DI ) ] . Serum fatty acids were quantified by using gas chromatography . Logistic and linear regression models were adjusted for demographic , lifestyle , and dietary variables . RESULTS Serum 15:0 was a significant biomarker for total dairy intake in the IRAS cohort . It was associated with a decreased incident diabetes risk ( OR : 0.73 , P = 0.02 ) and was positively associated with log SI ( β : 0.84 , P = 0.03 ) and log DI ( β : 2.21 , P = 0.02 ) in fully adjusted models . trans 16:1n-7 was a marker of total partially hydrogenated dietary fat intake and was not associated with outcomes in fully adjusted models . CONCLUSIONS Serum 15:0 , a marker of short-term intake of this fatty acid , was inversely associated with diabetes risk in this multiethnic cohort . This study may contribute to future recommendations regarding the benefits of dairy products on type 2 diabetes risk Saturated fatty acids ( SFA ) and monounsaturated fatty acids ( MUFA ) show different effects on the development of insulin resistance . In this study , we compared the effect of dietary SFA and MUFA on the insulin signaling pathway in the skeletal muscle of a type 2 diabetic animal model . Twenty-nine-week-old male Otsuka Long-Evans Tokushima fatty ( OLETF ) rats were r and omly divided into three groups and fed one of the following diets for 3 weeks ; a normal chow diet , an SFA ( lard oil ) enriched or a MUFA ( olive oil ) enriched high-fat diet . The vastus lateralis muscle was used for analyses . Insulin tolerance test showed improved insulin sensitivity in rats fed the MUFA diet , as compared to those fed the SFA diet ( p < 0.001 ) . The SFA diet reduced IRS-1 expression and phosphorylated PI3 K levels in skeletal muscle , as compared with a chow diet ( p < 0.001 , respectively ) . On the contrary , muscle IRS-2 expression and phosphorylated ERK1/2 was significantly increased in rats fed the SFA diet ( p < 0.001 , respectively ) . Membrane translocation of glucose transporter type 4 decreased in the skeletal muscle of rats fed the SFA diet , as compared to those fed a chow diet ( p < 0.001 ) . These changes in insulin signaling pathway in skeletal muscle were not observed in rats fed the MUFA diet . In conclusion , the beneficial effect of dietary MUFA on insulin sensitivity is associated with a conserved IRS-1/PI3 K insulin signaling pathway which was altered by dietary SFA BACKGROUND Polyunsaturated fatty acids ( PUFAs ) and monounsaturated fatty acids ( MUFAs ) have been shown to positively affect blood lipids ; however , their comparative effects on insulin sensitivity are unclear . OBJECTIVE Our objective was to investigate whether chronic intake of MUFAs or PUFAs improves insulin sensitivity in people with type 2 diabetes via stimulation of the endogenous gut hormone glucagon-like peptide 1 [ 7 - 36 ] amide ( GLP-1 ) . DESIGN Nine overweight people with type 2 diabetes received isoenergetic high-MUFA ( 20.3 + /- 3.5 % of total energy ) or high-PUFA ( 13.4 + /- 1 . 3 % ) diets for 24 d in a r and omized , double-blind crossover design . RESULTS Weight and glycemic control remained stable throughout the study . Despite a significant change in the plasma triacylglycerol linoleic-oleic acid ratio ( L : O ) with both diets ( MUFA : from 0.46 + /- 0.03 to 0.29 + /- 0.02 , P : < 0.005 ; PUFA : from 0.36 + /- 0.04 to 0.56 + /- 0.05 , P : < 0.05 ) and the phospholipid L : O ( 1.7 + /- 0.1 to 2.0 + /- 0.3 ; P : = 0.04 ) during consumption of the PUFA diet , this change was not associated with a change in insulin sensitivity , measured by the short-insulin-tolerance test . There was a significant reduction in the ratio of total to HDL cholesterol during consumption of the PUFA diet ( 5.2 + /- 0.4 compared with 4.7 + /- 0.3 ; P : = 0.005 ) but no change with the MUFA diet . There was no change in the fasting or postpr and ial incremental area under the curve in response to an identical st and ard test meal for glucose , insulin , triacylglycerol , nonesterified fatty acids , or GLP-1 . CONCLUSIONS Over the 3-wk intervention period , diet-induced change in the triacylglycerol or phospholipid L : O was not associated with either increased stimulation of GLP-1 or a change in insulin sensitivity in people with type 2 diabetes BACKGROUND The nature of dietary fats and fasting concentrations of triglycerides affect postpr and ial hypertriglyceridemia and glucose homeostasis . OBJECTIVES The objectives were to examine the effects of meals enriched in monounsaturated fatty acids ( MUFAs ) or saturated fatty acids ( SFAs ) on postpr and ial lipid , glucose , and insulin concentrations and to examine the extent of β cell function and insulin sensitivity in subjects with high fasting triglyceride concentrations . DESIGN Fourteen men with fasting hypertriglyceridemia and normal glucose tolerance were given meals ( ≈10 kcal/kg body weight ) containing MUFAs , SFAs , or no fat . Blood sample s were collected at baseline and hourly over 8 h for analysis . RESULTS The high-fat meals significantly increased postpr and ial concentrations of triglycerides , nonesterified fatty acids , and insulin and postpr and ial indexes of β cell function . However , postpr and ial indexes of insulin sensitivity decreased significantly . These effects were significantly attenuated with MUFAs relative to SFAs . CONCLUSIONS MUFAs postpr and ially buffered β cell hyperactivity and insulin intolerance relative to SFAs in subjects with high fasting triglyceride concentrations . These data suggest that , in contrast with SFAs , MUFA-based strategies may provide cardiovascular benefits to persons at risk by limiting lipid and insulin excursions and may contribute to optimal glycemic control after meal challenges BACKGROUND Hemostasis is the result of a complex equilibrium between coagulation and fibrinolysis , and the influence of different dietary models on this equilibrium is not entirely known . OBJECTIVE The objective was to compare the effects of the chronic intake of different dietary models on postpr and ial hemostasis . DESIGN In a r and omized crossover design , 20 healthy men consumed for 28 d each diets rich in monounsaturated fatty acids ( MUFAs ) , saturated fatty acids ( SFAs ) , and carbohydrates plus n-3 fatty acids ( CHO/N3 ) .  Fasting and postpr and ial hemostatic factors ( factor VII coagulant activity , plasminogen activator inhibitor-1 , tissue-type plasminogen activator , d-dimer , and thromboxane B(2 ) ) were measured ; meal tests for the postpr and ial measures were based on butter , virgin olive oil , and walnuts for the SFA , MUFA , and CHO/N3 diets , respectively . RESULTS There were no differences in the fasting variables after the dietary periods . After the 3 fatty meals were consumed , we observed an increase in thromboxane B(2 ) and d-dimer and a reduction in tissue plasminogen activator , irrespective of the dietary model . The MUFA or CHO/N3 meals lowered postpr and ial concentrations of factor VII coagulant activity , although the reduction was greater after the MUFA-enriched meal . The concentration of plasminogen activator inhibitor-1 was greater after the SFA meal than after the other 2 meals . CONCLUSIONS The administration of a fatty meal induces a postpr and ial procoagulant tendency , irrespective of the type of fat consumed . However , the use of a dietary model rich in SFA creates a more procoagulant environment than does a model that includes MUFA or CHO/N3 as the source of fatty acids BACKGROUND The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear . OBJECTIVE Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes . DESIGN We prospect ively followed 84204 women aged 34 - 59 y with no diabetes , cardiovascular disease , or cancer in 1980 . Detailed dietary information was assessed at baseline and up date d in 1984 , 1986 , and 1990 by using vali date d question naires . Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates . RESULTS During 14 y of follow-up , 2507 incident cases of type 2 diabetes  were documented . Total fat intake , compared with equivalent energy intake from carbohydrates , was not associated with risk of type 2 diabetes ; for a 5 % increase in total energy from fat , the relative risk ( RR ) was 0.98 ( 95 % CI : 0.94 , 1.02 ) . Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes . However , for a 5 % increase in energy from polyunsaturated fat , the RR was 0.63 ( 0.53 , 0.76 ; P < 0.0001 ) and for a 2 % increase in energy from trans fatty acids the RR was 1.39 ( 1.15 , 1.67 ; P = 0.0006 ) . We estimated that replacing 2 % of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40 % lower risk ( RR : 0.60 ; 95 % CI : 0.48 , 0.75 ) . CONCLUSIONS These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of  type 2 diabetes in women , but that trans fatty acids increase and polyunsaturated fatty acids reduce risk . Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially BACKGROUND Indian Asians in Western countries have a higher rate of coronary artery disease than do the indigenous white population s , and this higher rate may be influenced by a dietary imbalance of n-6 and n-3 polyunsaturated fatty acids ( PUFAs ) . OBJECTIVE The objective of the study was to test the hypothesis that a high background dietary intake of n-6 PUFA attenuates the effects of fish-oil supplementation on insulin sensitivity and associated blood lipids of the metabolic syndrome . DESIGN Twenty-nine Indian Asian men were recruited to participate in a 12-wk dietary intervention trial . Volunteers were r and omly assigned to receive either a moderate or a high n-6 PUFA diet featuring modified oils and spreads over a 6-wk period . After this 6-wk period , both groups were supplemented with 4.0 g fish oil/d ( 2.5 g eicosapentaenoic acid + docosahexaenoic acid ) for an additional 6 wk in combination with the dietary treatment . Volunteers participated in a postpr and ial study and an insulin sensitivity test after the 6-wk dietary intervention and again after the fish-oil supplementation period . RESULTS There was no significant time x treatment interaction for blood lipids or insulin action after dietary intervention with the moderate or high n-6 PUFA diets in combination with fish oil . After the 6-wk period of fish oil supplementation , fasting and postpr and ial plasma triacylglycerol concentrations decreased significantly . CONCLUSION The background dietary n-6 PUFA concentration did not modulate the effect of fish-oil supplementation on blood lipids or measures of insulin sensitivity in this ethnic group BACKGROUND Current dietary guidelines recommend the replacement of saturated fatty acids ( SAFAs ) with carbohydrates or monounsaturated fatty acids ( MUFAs ) based on evidence on lipid profile alone , the chronic effects of the mentioned replacements on insulin secretion and insulin sensitivity are however unclear . OBJECTIVE To assess the chronic effects of the substitution of refined carbohydrate or MUFA for SAFA on insulin secretion and insulin sensitivity in central ly obese subjects . METHODS Using a crossover design , r and omized controlled trial in abdominally overweight men and women , we compared the effects of substitution of 7 % energy as carbohydrate or MUFA for SAFA for a period of 6 weeks each . Fasting and postpr and ial blood sample s in response to corresponding SAFA , carbohydrate , or MUFA-enriched meal-challenges were collected after 6 weeks on each diet treatment for the assessment of outcomes . RESULTS As expected , postpr and ial nonesterified fatty acid suppression and elevation of C-peptide , insulin and glucose secretion were the greatest with high-carbohydrate ( CARB ) meal . Interestingly , CARB meal attenuated postpr and ial insulin secretion corrected for glucose response ; however , the insulin sensitivity and disposition index were not affected . SAFA and MUFA had similar effects on all markers except for fasting glucose-dependent insulinotropic peptide concentrations , which increased after MUFA but not SAFA when compared with CARB . CONCLUSION In conclusion , a 6-week lower-fat/higher-carbohydrate ( increased by 7 % refined carbohydrate ) diet may have greater adverse effect on insulin secretion corrected for glucose compared with isocaloric higher-fat diets . In contrast , exchanging MUFA for SAFA at 7 % energy had no appreciable adverse impact on insulin secretion BACKGROUND The effect of individual dietary fatty acids on emerging risk factors for cardiovascular disease that are associated with sub clinical inflammation is unknown . OBJECTIVE The goal was to evaluate the role of dietary fat and specific fatty acids , especially trans fatty acids , in altering concentrations of markers of inflammation in humans fed controlled diets . DESIGN In a r and omized crossover design , 50 men consumed controlled diets for 5 wk that provided 15 % of energy from protein , 39 % of energy from fat , and 46 % of energy from carbohydrate . Eight percent of fat or fatty acids was replaced across diets with the following : cholesterol , oleic acid , trans fatty acids ( TFAs ) , stearic acid ( STE ) , TFA+STE ( 4 % of energy each ) , and 12:0 - 16:0 saturated fatty acids ( LMP ) . RESULTS Fibrinogen concentrations were higher after consumption of the diet enriched in stearic acid than after consumption of the carbohydrate diet . C-reactive protein concentrations were higher after consumption of the TFA diet than after consumption of the carbohydrate diet , but were not significantly different after consumption of the TFA and TFA+STE diets than after consumption of the LMP diet .  Interleukin 6 concentrations were lower after consumption of the oleic acid diet than after consumption of the LMP , TFA , and STE diets .  E-selectin concentrations were higher after consumption of the TFA diet than after consumption of the carbohydrate diet . Consumption of the TFA but not the TFA+STE diet result ed in higher E-selectin concentrations than did the LMP diet . CONCLUSIONS These data provide evidence that dietary fatty acids can modulate markers of inflammation . Although stearic acid minimally affects LDL cholesterol , it does appear to increase fibrinogen concentrations
RESULTS Increased TFA intake did not result in significant changes in glucose or insulin concentrations .
Our analysis also showed the absence of publication bias and any dose-response relations between the ES and TFA intake .
Increased TFA intake does not result in changes in glucose , insulin , or triglyceride concentrations but leads to an increase in total and LDL-cholesterol and a decrease in HDL-cholesterol concentrations .
There is no evidence to support a potential benefit of the reduction of dietary TFA intake on glucose homeostasis
BACKGROUND Although evidence from cohort studies has suggested that trans fatty acid ( TFA ) consumption may be associated with insulin resistance and diabetes , r and omized placebo-controlled trials ( RCTs ) have yielded conflicting results .
OBJECTIVE In a meta- analysis , we combined all available RCTs that examined the role of  TFA intake  on  glucose homeostasis .