Effects of 4-week very-high-fructose/glucose diets on insulin sensitivity, visceral fat and intrahepatic lipids: an exploratory trial. The effects of four hypocaloric diets containing different levels of sucrose or high fructose corn syrup on weight loss and related parameters The Effect of Normally Consumed Amounts of Sucrose or High Fructose Corn Syrup on Lipid Profiles, Body Composition and Related Parameters in Overweight/Obese Subjects Effects of a short-term overfeeding with fructose or glucose in healthy young males. Dietary Fructose Reduction Improves Markers of Cardiovascular Disease Risk in Hispanic-American Adolescents with NAFLD Simultaneous ingestion of fructose and fat exacerbates postprandial exogenous lipidemia in young healthy Japanese women. Exercise performed immediately after fructose ingestion enhances fructose oxidation and suppresses fructose storage. Fructose ingestion acutely elevates blood pressure in healthy young humans. The effects of glucose, fructose, and sucrose ingestion during exercise. Effects of fructose vs glucose on regional cerebral blood flow in brain regions involved with appetite and reward pathways. Mechanisms for the acute effect of fructose on postprandial lipemia. Moderate Amounts of Fructose Consumption Impair Insulin Sensitivity in Healthy Young Men Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women. Consumption of fructose-sweetened beverages for 10 weeks reduces net fat oxidation and energy expenditure in overweight/obese men and women High-fructose corn syrup and sucrose have equivalent effects on energy-regulating hormones at normal human consumption levels. Acute effects of feeding fructose, glucose and sucrose on blood lipid levels and systemic inflammation Consumption of fructose- but not glucose-sweetened beverages for 10 weeks increases circulating concentrations of uric acid, retinol binding protein-4, and gamma-glutamyl transferase activity in overweight/obese humans
An increasing amount of fructose in the diet is suggested to play a causal role in the pathogenesis of the metabolic syndrome , type 2 diabetes and fatty liver . Our aim was to investigate and compare the effects of very high fructose and very high glucose in hyperenergetic diets on glucose and lipid metabolism and on fat depots in healthy humans . We conducted an exploratory , prospect i ve , r and omised , single-blinded , intervention trial . Participants in addition to a balanced weight-maintaining diet received 150 g of fructose or glucose/d for 4 weeks . Insulin sensitivity was estimated from oral glucose tolerance tests . Visceral and subcutaneous abdominal fat was determined with MRI . Liver fat and intramyocellular lipids of the tibialis anterior muscle were measured with (1)H magnetic resonance spectroscopy . A total of twenty healthy subjects ( fructose group n 10 and glucose group n 10 ; twelve males and eight females ) completed the study . They had a mean age of 30·5 ( SEM 2·0 ) years and a mean BMI of 25·9 ( SEM 0·5 ) kg/m(2 ) . Insulin sensitivity appeared to decrease both in the fructose and glucose groups . TAG markedly increased in the fructose group . No strong alterations or treatment effects were found for liver fat , visceral fat , subcutaneous abdominal fat and intramyocellular lipids of the tibialis anterior muscle . In conclusion , the effects of very high fructose and very high glucose in hyperenergetic diets on glucose metabolism and body fat composition were not different in the healthy participants of the present study . However , elevation of plasma TAG seemed to be fructose-specific Background The replacement of sucrose with HFCS in food products has been suggested as playing a role in the development of obesity as a public health issue . The objective of this study was to examine the effects of four equally hypocaloric diets containing different levels of sucrose or high fructose corn syrup ( HFCS ) . Methods This was a r and omized , prospect i ve , double blind trial , with overweight/obese participants measured for body composition and blood chemistry before and after the completion of 12 weeks following a hypocaloric diet .  The average caloric deficit achieved on the hypocaloric diets was 309 kcal . Results Reductions were observed in all measures of adiposity including body mass , BMI , % body fat , waist circumference and fat mass for all four hypocaloric groups , as well as reductions in the exercise only group for body mass , BMI and waist circumference . Conclusions Similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are fed hypocaloric diets containing levels of sucrose or high fructose corn syrup typically consumed by adults in the United States The American Heart Association ( AHA ) has advocated that women and men not consume more than 100 and 150 kcal/day , respectively , from added sugars . These levels are currently exceeded by over 90 % of the adult population in the United States . Few data exist on longer-term metabolic effects when sucrose and High Fructose Corn Syrup ( HFCS ) , the principal sources of added dietary sugars , are consumed at levels typical of the general population . Sixty five overweight and obese individuals were placed on a eucaloric ( weight stable ) diet for 10-weeks , which incorporated sucrose- or HFCS-sweetened , low-fat milk at 10 % or 20 % of calories in a r and omized , double-blinded study . All groups responded similarly ( interaction p > 0.05 ) . There was no change in body weight in any of the groups over the 10-week study , or in systolic or diastolic blood pressure . Likewise , there were no changes in total cholesterol , triglycerides , low-density lipoprotein ( LDL ) , or apolipoprotein B ( Apo B ) . We conclude that ( 1 ) when consumed as part of a eucaloric diet fructose — when given with glucose ( as normally consumed ) does not promote weight gain or an atherogenic lipid profile even when consumed at two to four times the level recently recommended by the AHA . ( 2 ) There were no differences between HFCS and sucrose on these parameters Consumption of simple carbohydrates has markedly increased over the past decades , and may be involved in the increased prevalence in metabolic diseases . Whether an increased intake of fructose is specifically related to a dysregulation of glucose and lipid metabolism remains controversial . We therefore compared the effects of hypercaloric diets enriched with fructose ( HFrD ) or glucose ( HGlcD ) in healthy men . Eleven subjects were studied in a r and omised order after 7 d of the following diets : ( 1 ) weight maintenance , control diet ; ( 2 ) HFrD ( 3.5 g fructose/kg fat-free mass ( ffm ) per d , + 35 % energy intake ) ; ( 3 ) HGlcD ( 3.5 g glucose/kg ffm per d , + 35 % energy intake ) . Fasting hepatic glucose output ( HGO ) was measured with 6,6 - 2H2-glucose . Intrahepatocellular lipids ( IHCL ) and intramyocellular lipids ( IMCL ) were measured by 1H magnetic resonance spectroscopy . Both fructose and glucose increased fasting VLDL-TAG ( HFrD : + 59 % , P < 0.05 ; HGlcD : + 31 % , P = 0.11 ) and IHCL ( HFrD : + 52 % , P < 0.05 ; HGlcD : + 58 % , P = 0.06 ) . HGO increased after both diets ( HFrD : + 5 % , P < 0.05 ; HGlcD : + 5 % , P = 0.05 ) . No change was observed in fasting glycaemia , insulin and alanine aminotransferase concentrations . IMCL increased significantly only after the HGlcD ( HFrD : + 24 % , NS ; HGlcD : + 59 % , P < 0.05 ) . IHCL and VLDL-TAG were not different between hypercaloric HFrD and HGlcD , but were increased compared to values observed with a weight maintenance diet . However , glucose led to a higher increase in IMCL than fructose Nonalcoholic fatty liver disease ( NAFLD ) is now thought to be the most common liver disease worldwide . Cardiovascular complications are a leading cause of mortality in NAFLD . Fructose , a common nutrient in the westernized diet , has been reported to be associated with increased cardiovascular risk , but its impact on adolescents with NAFLD is not well understood . We design ed a 4-week r and omized , controlled , double-blinded beverage intervention study . Twenty-four overweight Hispanic-American adolescents who had hepatic fat > 8 % on imaging and who were regular consumers of sweet beverages were enrolled and r and omized to calorie-matched study -provided fructose only or glucose only beverages . After 4 weeks , there was no significant change in hepatic fat or body weight in either group . In the glucose beverage group there was significantly improved adipose insulin sensitivity , high sensitivity C-reactive protein ( hs-CRP ) , and low-density lipoprotein ( LDL ) oxidation . These findings demonstrate that reduction of fructose improves several important factors related to cardiovascular disease despite a lack of measurable improvement in hepatic steatosis . Reducing dietary fructose may be an effective intervention to blunt atherosclerosis progression among NAFLD patients and should be evaluated in longer term clinical trials AIM To investigate the acute effects of the simultaneous ingestion of fructose and fat on postpr and ial lipoprotein metabolism in healthy young women . METHODS Nine young healthy Japanese women with a normal weight ( body mass index : 18.5≤- < 25 kg/m(2 ) ) , a normal ovarian cycle and an apolipoprotein E 3/3 phenotype were enrolled as participants and studied on four occasions . At each session , the subjects ingested one of four beverages containing either glucose or fructose ( 0.5 g/kg body weight each ) with or without OFTT cream ( 1 g/kg , 0.35 g/ kg as fat ) in a r and omized crossover design . Blood sample s were collected at baseline and at 0.5 , 1 , 2 , 4 and 6 hours after ingestion . RESULTS The ingestion of fructose combined with fat led to significantly higher rises in the serum triglyceride ( TG ) , remnant-like particle (RLP)-TG , remnant lipoprotein-cholesterol ( RemL-C ) and apolipoprotein B-48 ( apoB48 ) concentrations with delayed peaks compared with that observed following ingestion of the other three types of beverages . The incremental area under the curve (ΔAUC)-TG and ΔAUC-apoB48 were larger than those observed for the ingestion of fat only . The serum RLP-TG and apoB48 concentrations returned to the fasting levels ( 0 hours ) at the end of the test ( 6 hours ) following the ingestion of fat only ; however , these concentrations did not return to the fasting levels following the intake of fructose combined with fat . CONCLUSIONS These findings suggest a delay in the clearance of intestinal TG-rich lipoproteins , namely chylomicron and its remnant , following the ingestion of fructose combined with fat . The simultaneous ingestion of fructose and fat markedly enhances postpr and ial exogenous lipidemia in young healthy Japanese women BACKGROUND Exercise prevents the adverse effects of a  high-fructose diet through mechanisms that remain unknown . OBJECTIVE We assessed the hypothesis that exercise prevents fructose-induced increases in very-low-density lipoprotein ( VLDL ) triglycerides by decreasing the fructose conversion into glucose and VLDL-triglyceride and fructose carbon storage into hepatic glycogen and lipids . DESIGN Eight healthy men were studied on 3 occasions after 4 d consuming a  weight-maintenance , high-fructose diet . On the fifth day , the men ingested an oral (13)C-labeled fructose load ( 0.75 g/kg ) , and their total fructose oxidation ( (13)CO2 production ) , fructose storage ( fructose ingestion minus (13)C-fructose oxidation ) , fructose conversion into blood (13)C glucose ( gluconeogenesis from fructose ) , blood VLDL-(13)C palmitate ( a marker of hepatic de novo lipogenesis ) , and lactate concentrations were monitored over 7 postpr and ial h. On one occasion , participants remained lying down throughout the experiment [ fructose treatment alone with no exercise condition ( NoEx ) ] , and on the other 2 occasions , they performed a 60-min exercise either 75 min before fructose ingestion [ exercise , then fructose condition ( ExFru ) ] or 90 min after fructose ingestion [ fructose , then exercise condition ( FruEx ) ] . RESULTS Fructose oxidation was significantly ( P < 0.001 ) higher in the FruEx ( 80 % ± 3 % of ingested fructose ) than in the ExFru ( 46 % ± 1 % ) and NoEx ( 49 % ± 1 % ) . Consequently , fructose storage was lower in the FruEx than in the other 2 conditions ( P < 0.001 ) . Fructose conversion into blood (13)C glucose , VLDL-(13)C palmitate , and postpr and ial plasma lactate concentrations was not significantly different between conditions . CONCLUSIONS Compared with sedentary conditions , exercise performed immediately after fructose ingestion increases fructose oxidation and decreases fructose storage . In contrast , exercise performed before fructose ingestion does not significantly alter fructose oxidation and storage . In both conditions , exercise did not abolish fructose conversion into glucose or its incorporation into VLDL triglycerides . This trial was registered at clinical trials.gov as NCT01866215 Overconsumption of fructose , particularly in the form of soft drinks , is increasingly recognized as a public health concern . The acute cardiovascular responses to ingesting fructose have not , however , been well-studied in humans . In this r and omized crossover study , we compared cardiovascular autonomic regulation after ingesting water and drinks containing either glucose or fructose in 15 healthy volunteers ( aged 21 - 33 yr ) . The total volume of each drink was 500 ml , and the sugar content 60 g. For 30 min before and 2 h after each drink , we recorded beat-to-beat heart rate , arterial blood pressure , and cardiac output . Energy expenditure was determined on a minute-by-minute basis . Ingesting the fructose drink significantly increased blood pressure , heart rate , and cardiac output but not total peripheral resistance . Glucose ingestion result ed in a significantly greater increase in cardiac output than fructose but no change in blood pressure and a concomitant decrease in total peripheral resistance . Ingesting glucose and fructose , but not water , significantly increased blood pressure variability and decreased cardiovagal baroreflex sensitivity . Energy expenditure increased by a similar amount after glucose and fructose ingestion , but fructose elicited a significantly greater increase in respiratory quotient . These results show that ingestion of glucose and fructose drinks is characterized by specific hemodynamic responses . In particular , fructose ingestion elicits an increase in blood pressure that is probably mediated by an increase in cardiac output without compensatory peripheral vasodilatation The purpose of this study was to compare the physiological , sensory , and exercise performance responses to ingestion of 6 % glucose , 6 % fructose , and 6 % sucrose solutions during cycling exercise . Twelve subjects completed three sessions consisting of 115 min of intermittent cycle ergometer exercise at 65 - 80 % of VO2max followed by a timed performance bout requiring the completion of 600 pedal revolutions . During each of five 4-min rest periods , subjects consumed 3 ml.kg LBM-1 of one of the beverages . Beverages were presented in counterbalanced , double-blind fashion . Heart rate , VO2 , plasma urate , plasma lactate , respiratory exchange ratio , and carbohydrate combustion rates changed similarly among beverage treatment . However , fructose was associated with lower plasma glucose and serum insulin , a larger loss of plasma volume , greater gastrointestinal distress and relative perceived exertion ratings , and higher plasma or serum concentrations of free fatty acids , fructose , and cortisol values than sucrose or glucose ( P less than 0.05 ) . Compared to sucrose and glucose , fructose feeding also result ed in lower lactate and HR values during the performance bout ( P less than 0.05 ) . Mean + /- SE cycling performance times were faster with sucrose and glucose than with fructose : 419.4 + /- 21.0 s , 423.9 + /- 21.2 s , and 488.3 + /- 21.1 s , respectively ( P less than 0.05 ) . Relative to 6 % solutions of sucrose and glucose , ingestion of a 6 % fructose beverage is associated with gastrointestinal distress , compromised physiological response , and reduced exercise capacity IMPORTANCE Increases in fructose consumption have paralleled the increasing prevalence of obesity , and high-fructose diets are thought to promote weight gain and insulin resistance . Fructose ingestion produces smaller increases in circulating satiety hormones compared with glucose ingestion , and central administration of fructose provokes feeding in rodents , whereas central ly administered glucose promotes satiety . OBJECTIVE To study neurophysiological factors that might underlie associations between fructose consumption and weight gain . DESIGN , SETTING , AND PARTICIPANTS Twenty healthy adult volunteers underwent 2 magnetic resonance imaging sessions at Yale University in conjunction with fructose or glucose drink ingestion in a blinded , r and om-order , crossover design . MAIN OUTCOME MEASURES Relative changes in hypothalamic regional cerebral blood flow ( CBF ) after glucose or fructose ingestion . Secondary outcomes included whole-brain analyses to explore regional CBF changes , functional connectivity analysis to investigate correlations between the hypothalamus and other brain region responses , and hormone responses to fructose and glucose ingestion . RESULTS There was a significantly greater reduction in hypothalamic CBF after glucose vs fructose ingestion ( -5.45 vs 2.84 mL/g per minute , respectively ; mean difference , 8.3 mL/g per minute [ 95 % CI of mean difference , 1.87 - 14.70 ] ; P = .01 ) . Glucose ingestion ( compared with baseline ) increased functional connectivity between the hypothalamus and the thalamus and striatum . Fructose  increased connectivity between the hypothalamus and thalamus but not the striatum . Regional CBF within the hypothalamus , thalamus , insula , anterior cingulate , and striatum ( appetite and reward regions ) was reduced after glucose ingestion compared with baseline ( P < .05 significance threshold , family-wise error [ FWE ] whole-brain corrected ) . In contrast , fructose  reduced regional CBF in the thalamus , hippocampus , posterior cingulate cortex , fusiform , and visual cortex ( P < .05 significance threshold , FWE whole-brain corrected ) . In whole-brain voxel-level analyses , there were no significant differences between direct comparisons of fructose vs glucose sessions following correction for multiple comparisons . Fructose vs glucose ingestion result ed in lower peak levels of serum glucose ( mean difference , 41.0 mg/dL [ 95 % CI , 27.7 - 54.5 ] ; P < .001 ) , insulin ( mean difference , 49.6 μU/mL [ 95 % CI , 38.2 - 61.1 ] ; P < .001 ) , and glucagon-like polypeptide 1 ( mean difference , 2.1 pmol/L [ 95 % CI , 0.9 - 3.2 ] ; P = .01 ) . CONCLUSION AND RELEVANCE In a series of exploratory analyses , consumption of fructose compared with glucose result ed in a distinct pattern of regional CBF and a smaller increase in systemic glucose , insulin , and glucagon-like polypeptide 1 levels BACKGROUND A high fructose intake can lead to postpr and ial hypertriacylglycerolemia . The underlying mechanism is unclear . OBJECTIVE The objective of the study was to investigate the mechanisms involved in fructose-induced hypertriacylglycerolemia and the contribution of de novo lipogenesis in an acute setting . DESIGN In a r and omized , crossover study , 14 subjects were given a fructose or glucose test meal after an overnight fast . [(2)H2]Palmitate and [U(13)C]d-fructose or [U(13)C]d-glucose were added to trace the h and ling of dietary fats and the fate of dietary sugars in the body . Blood sample s were taken before and after the meal . Respiratory exchange ratio was measured by using indirect calorimetry , and breath sample s were collected . RESULTS Plasma triacylglycerol and VLDL-triacylglycerol concentrations were significantly higher ( P = 0.001 for both ) , whereas the concentrations of insulin and [(2)H2]palmitate in nonesterified fatty acids were significantly lower after fructose than after glucose ( P = 0.002 and 0.03 , respectively ) . The respiratory exchange ratio was higher after fructose ( P = 0.04 ) ; significantly ( P = 0.003 ) more carbon from sugars was recovered in breath carbon dioxide over 6 h after fructose ( 30.5 % ) than after glucose ( 24.5 % ) . At 240 min , newly synthesized fatty acids from fructose made up approximately 0.4 % of circulating VLDL-triacylglycerol , whereas newly synthesized triacylglycerol-glycerol made up 38 % . Newly synthesized fatty acids and triacylglycerol-glycerol from glucose contributed almost none of VLDL-triacylglycerol ( P = 0.002 and 0.007 for glucose and fructose , respectively ) . CONCLUSIONS The lower insulin excursion after fructose may result in less activation of adipose tissue lipoprotein lipase , which led to impaired triacylglycerol clearance . The contribution of de novo lipogenesis to fructose-induced hypertriacylglycerolemia is small , but its effect on altering the partitioning of fatty acids toward esterification may be considerable OBJECTIVE Adverse effects of hypercaloric , high-fructose diets on insulin sensitivity and lipids in human subjects have been shown repeatedly . The implication s of fructose in amounts close to usual daily consumption , however , have not been well studied . This study assessed the effect of moderate amounts of fructose and sucrose compared with glucose on glucose and lipid metabolism . RESEARCH DESIGN AND METHODS Nine healthy , normal-weight male volunteers ( aged 21–25 years ) were studied in this double-blind , r and omized , cross-over trial . All subjects consumed four different sweetened beverages ( 600 mL/day ) for 3 weeks each : medium fructose ( MF ) at 40 g/day , and high fructose ( HF ) , high glucose ( HG ) , and high sucrose ( HS ) each at 80 g/day . Euglycemic-hyperinsulinemic clamps with [6,6]-2H2 glucose labeling were used to measure endogenous glucose production . Lipid profile , glucose , and insulin were measured in fasting sample s. RESULTS Hepatic suppression of glucose production during the clamp was significantly lower after HF ( 59.4 ± 11.0 % ) than HG ( 70.3 ± 10.5 % , P < 0.05 ) , whereas fasting glucose , insulin , and C-peptide did not differ between the interventions . Compared with HG , LDL cholesterol and total cholesterol were significantly higher after MF , HF , and HS , and free fatty acids were significantly increased after MF , but not after the two other interventions ( P < 0.05 ) . Subjects ’ energy intake during the interventions did not differ significantly from baseline intake . CONCLUSIONS This study clearly shows that moderate amounts of fructose and sucrose significantly alter hepatic insulin sensitivity and lipid metabolism compared with similar amounts of glucose OBJECTIVE Fructose has been implicated in obesity , partly due to lack of insulin-mediated leptin stimulation and ghrelin suppression . Most work has examined effects of pure fructose , rather than high-fructose corn syrup ( HFCS ) , the most commonly consumed form of fructose . This study examined effects of beverages sweetened with HFCS or sucrose ( Suc ) , when consumed with mixed meals , on blood glucose , insulin , leptin , ghrelin , and appetite . METHODS Thirty lean women were studied on two r and omized 2-d visits during which HFCS- and Suc-sweetened beverages were consumed as 30 % of energy on isocaloric diets during day 1 while blood was sample d. On day 2 , food was eaten ad libitum . Subjects rated appetite at design ated times throughout visits . RESULTS No significant differences between the two sweeteners were seen in fasting plasma glucose , insulin , leptin , and ghrelin ( P > 0.05 ) . The within-day variation in all four items was not different between the two visits ( P > 0.05 ) . Net areas under the curve were similar for glucose , insulin , and leptin ( P > 0.05 ) . There were no differences in energy or macronutrient intake on day 2 . The only appetite variable that differed between sweeteners was desire to eat , which had a higher area under the curve the day after Suc compared with HFCS . CONCLUSION These short-term results suggest that , when fructose is consumed in the form of HFCS , the measured metabolic responses do not differ from Suc in lean women . Further research is required to examine appetite responses and to determine if these findings hold true for obese individuals , males , or longer periods Background / Objectives : The results of short-term studies in humans suggest that , compared with glucose , acute consumption of fructose leads to increased postpr and ial energy expenditure and carbohydrate oxidation and decreased postpr and ial fat oxidation . The objective of this study was to determine the potential effects of increased fructose consumption compared with isocaloric glucose consumption on substrate utilization and energy expenditure following sustained consumption and under energy-balanced conditions . Subjects/ Methods : As part of a parallel arm study , overweight/obese male and female subjects , 40–72 years , consumed glucose- or fructose-sweetened beverages providing 25 % of energy requirements for 10 weeks . Energy expenditure and substrate utilization were assessed using indirect calorimetry at baseline and during the 10th week of intervention . Results : Consumption of fructose , but not glucose , led to significant decreases of net postpr and ial fat oxidation and significant increases of net postpr and ial carbohydrate oxidation ( P<0.0001 for both ) . Resting energy expenditure ( REE ) decreased significantly from baseline values in subjects consuming fructose ( P=0.031 ) but not in those consuming glucose . Conclusions : Increased consumption of fructose for 10 weeks leads to marked changes of postpr and ial substrate utilization including a significant reduction of net fat oxidation . In addition , we report that REE is reduced compared with baseline values in subjects consuming fructose-sweetened beverages for 10 weeks Intake of high-fructose corn syrup ( HFCS ) has been suggested to contribute to the increased prevalence of obesity , whereas a number of studies and organizations have reported metabolic equivalence between HFCS and sucrose . We hypothesized that HFCS and sucrose would have similar effects on energy-regulating hormones and metabolic substrates at normal levels of human consumption and that these values would not change over a 10-week , free-living period at these consumption levels . This was a r and omized , prospect i ve , double-blind , parallel group study in which 138 adult men and women consumed 10 weeks of low-fat milk sweetened with either HFCS or sucrose at levels of the 25th , 50th , and 90th percentile population consumption of fructose ( the equivalent of 40 , 90 , or 150 g of sugar per day in a 2000-kcal diet ) . Before and after the 10-week intervention , 24-hour blood sample s were collected . The area under the curve ( AUC ) for glucose , insulin , leptin , active ghrelin , triglyceride , and uric acid was measured . There were no group differences at baseline or posttesting for all outcomes ( interaction , P > .05 ) . The AUC response of glucose , active ghrelin , and uric acid did not change between baseline and posttesting ( P > .05 ) , whereas the AUC response of insulin ( P < .05 ) , leptin ( P < .001 ) , and triglyceride ( P < .01 ) increased over the course of the intervention when the 6 groups were averaged . We conclude that there are no differences in the metabolic effects of HFCS and sucrose when compared at low , medium , and high levels of consumption Background Recent studies have demonstrated a relationship between fructose consumption and risk of developing metabolic syndrome . Mechanisms by which dietary fructose mediates metabolic changes are poorly understood . This study compared the effects of fructose , glucose and sucrose consumption on post-postpr and ial lipemia and low grade inflammation measured as hs-CRP . Methods This was a r and omized , single blinded , cross-over trial involving healthy subjects ( n = 14 ) . After an overnight fast , participants were given one of 3 different isocaloric drinks , containing 50 g of either fructose or glucose or sucrose dissolved in water .  Blood sample s were collected at baseline , 30 , 60 and 120 minutes post intervention for the analysis of blood lipids , glucose , insulin and high sensitivity C-reactive protein ( hs-CRP ) . Results Glucose and sucrose supplementation initially result ed in a significant increase in glucose and insulin levels compared to fructose supplementation and returned to near baseline values within 2 hours . Change in plasma cholesterol , LDL and HDL-cholesterol ( measured as area under curve , AUC ) was significantly higher when participants consumed fructose compared with glucose or sucrose ( P < 0.05 ) . AUC for plasma triglyceride levels however remained unchanged regardless of the dietary intervention . Change in AUC for hs-CRP was also significantly higher in subjects consuming fructose compared with those consuming glucose ( P < 0.05 ) , but not sucrose ( P = 0.07 ) . Conclusion This study demonstrates that fructose as a sole source of energy modulates plasma lipids and hsCRP levels in healthy individuals . The significance of increase in HDL-cholesterol with a concurrent increase in LDL-cholesterol and elevated hs-CRP levels remains to be delineated when considering health effects of feeding fructose-rich diets . Registration number for clinical Background Prospect i ve studies in humans examining the effects of fructose consumption on biological markers associated with the development of metabolic syndrome are lacking . Therefore we investigated the relative effects of 10 wks of fructose or glucose consumption on plasma uric acid and RBP-4 concentrations , as well as liver enzyme ( AST , ALT , and GGT ) activities in men and women . Methods As part of a parallel arm study , older ( age 40–72 ) , overweight and obese male and female subjects ( BMI 25–35 kg/m2 ) consumed glucose- or fructose-sweetened beverages providing 25 % of energy requirements for 10 wks . Fasting and 24-h blood collection s were performed at baseline and following 10 wks of intervention and plasma concentrations of uric acid , RBP-4 and liver enzyme activities were measured . Results Consumption of fructose , but not glucose , led to significant increases of 24-h uric acid profiles ( P < 0.0001 ) and RBP-4 concentrations ( P = 0.012 ) , as well as plasma GGT activity ( P = 0.04 ) . Fasting plasma uric acid concentrations increased in both groups ; however , the response was significantly greater in subjects consuming fructose ( P = 0.002 for effect of sugar ) . Within the fructose group male subjects exhibited larger increases of RBP-4 levels than women ( P = 0.024 ) . Conclusions These findings suggest that consumption of fructose at 25 % of energy requirements for 10 wks , compared with isocaloric consumption of glucose , may contribute to the development of components of the metabolic syndrome by increasing circulating uric acid , GGT activity , suggesting alteration of hepatic function , and the production of RBP-4
Pooled analyses show that although fructose may increase total cholesterol , uric acid , and postpr and ial triglycerides in isocaloric replacement for glucose , it does not appear to be any worse than glucose in its effects on other aspects of the lipid profile , insulin , or markers of nonalcoholic fatty liver disease .
It may also have important advantages over glucose for body weight , glycemic control , and blood pressure .
SUMMARY Depending on the cardiometabolic endpoint in question , fructose has variable effects when replacing glucose .
PURPOSE OF REVIEW Fructose is seen as uniquely contributing to the p and emics of obesity and its cardiometabolic complications .
Much of the evidence for this view derives from the unique biochemical , metabolic , and endocrine responses that differentiate fructose from glucose .
To underst and whether these proposed mechanisms result in clinical ly meaningful modification of cardiovascular risk in humans , we up date a series of systematic review s and meta-analyses of controlled feeding trials to assess the cardiometabolic effects of fructose in isocaloric replacement for glucose .