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 Effects of 4-week very-high-fructose/glucose diets on insulin sensitivity, visceral fat and intrahepatic lipids: an exploratory trial. Inulin supplementation prevents high fructose diet-induced hypertension in rats. Effect of prior ingestion of glucose or fructose on the performance of exercise of intermediate duration High-fructose corn syrup and sucrose have equivalent effects on energy-regulating hormones at normal human consumption levels. Blood lipids, lipoproteins, apoproteins, and uric acid in men fed diets containing fructose or high-amylose cornstarch. Grape Polyphenols Prevent Fructose-Induced Oxidative Stress and Insulin Resistance in First-Degree Relatives of Type 2 Diabetic Patients Acute effects of feeding fructose, glucose and sucrose on blood lipid levels and systemic inflammation Dietary triggers of abdominal symptoms in patients with irritable bowel syndrome: randomized placebo-controlled evidence. Moderate Amounts of Fructose Consumption Impair Insulin Sensitivity in Healthy Young Men
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 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 & AIMS The aim of this experiment was to evaluate the potential beneficial effect of supplementation with different inulin-type fructan fractions against common features of the metabolic syndrome in a rat model of this syndrome ( fructose-fed rat ) . METHODS Forty Wistar rats were r and omly divided into five groups and the animals received for 4 weeks either a semi-purified starch or fructose-based diet , or diets in which fructose was partially substituted with various fructans : 10 g/100 g of long-chain inulin or oligofructose , or an oligofructose-enriched inulin . After this period , blood pressure was measured and sample s of blood and tissues were collected for selected biochemical analyses . RESULTS As compared to the starch-fed group , the fructose-fed rats presented : hypertriglyceridemia , hypertension , increased susceptibility to heart peroxidation and renal damages . Long-chain inulin and oligofructose-enriched inulin supplementation prevented fructose induced elevated blood pressure , susceptibility to heart peroxidation and renal damages . All inulin-type fructans containing diets prevented fructose induced hypertriglyceridemia . CONCLUSIONS These results suggest that supplementation with inulin-type fructans is efficient against fructose induced hypertension and that effects are most pronounced for long-chain inulin and oligofructose-enriched inulin . We hypothesize that the anti-hypertensive effect of inulin could be explained by the reduction of the high fructose induced oxidative stress The metabolic responses induced by the ingestion of a beverage containing glucose ( G ) , fructose ( F ) or placebo ( W ) 30 min before exercise of high intensity and intermediate duration have been investigated ; in these conditions the energy processes are mostly dependent on aerobic reactions . A group of 11 male recreational sportsmen ran on a treadmill , at an intensity corresponding to 82 % of peak oxygen consumption , until exhaustion on three different occasions ( after ingestion of a beverage containing 75 g of G , 75 g of F or W ) . Plasma glucose , insulin , and lactic acid concentrations were determined just prior to the ingestion of the beverages , 30 min afterwards and 10 and 30 min after completion of the exercise . The mean endurance time was 644 ( SD 261 ) s after the ingestion of G , 611 ( SD 227 ) s after the ingestion of F and 584 ( SD 189 ) s after the ingestion of the W ( P < 0.05 between G and W ) . No differences in the oxygen uptake , respiratory quotient or lactate concentrations between the three trials were observed . Both plasma glucose and insulin concentrations determined in sample s obtained immediately before the onset of exercise were higher when G was ingested than when F ( P < 0.05 and P < 0.05 , respectively ) or W ( P < 0.001 and P < 0.005 , respectively ) were ingested . These findings would suggest that the ingestion of G prior to an effort of intermediate duration may improve physical performance 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 Ten hyperinsulinemic and 11 nonhyperinsulinemic men consumed for 5 wk each in a cross-over design a diet , similar to one currently consumed in the United States , with 20 % of the kilocalories from either fructose or high-amylose cornstarch to determine the effects of the two diets on various blood metabolites considered to be risk factors associated with heart disease . In the hyperinsulinemic men the intake of fructose as compared with cornstarch significantly increased total triglycerides and their lipoprotein distribution ; total and very-low-density lipoprotein cholesterol ; apoproteins B-100 , C-II , C-III ; and uric acid . In the nonhyperinsulinemic men  total triglycerides , total and low-density lipoprotein cholesterol and uric acid were significantly greater after the consumption of fructose than after cornstarch . The results indicate that in a diet high in saturated fatty acids and cholesterol , fructose increases the levels of risk factors associated with heart disease , especially in hyperinsulinemic men OBJECTIVE To assess the clinical efficacy of nutritional amounts of grape polyphenols ( PPs ) in counteracting the metabolic alterations of high-fructose diet , including oxidative stress and insulin resistance ( IR ) , in healthy volunteers with high metabolic risk . RESEARCH DESIGN AND METHODS Thirty-eight healthy overweight/obese first-degree relatives of type 2 diabetic patients ( 18 men and 20 women ) were r and omized in a double-blind controlled trial between a grape PP ( 2 g/day ) and a placebo ( PCB ) group . Subjects were investigated at baseline and after 8 and 9 weeks of supplementation , the last 6 days of which they all received 3 g/kg fat-free mass/day of fructose . The primary end point was the protective effect of  grape PPs  on fructose-induced IR . RESULTS In the PCB group , fructose induced 1 ) a 20 % decrease in hepatic insulin sensitivity index ( P < 0.05 ) and an 11 % decrease in glucose infusion rate ( P < 0.05 ) as evaluated during a two-step hyperinsulinemic-euglycemic clamp , 2 ) an increase in systemic ( urinary F2-isoprostanes ) and muscle ( thiobarbituric acid – reactive substances and protein carbonylation ) oxidative stress ( P < 0.05 ) , and 3 ) a downregulation of mitochondrial genes and decreased mitochondrial respiration ( P < 0.05 ) . All the deleterious effects of fructose were fully blunted by grape PP supplementation . Antioxidative defenses , inflammatory markers , and main adipokines were affected neither by fructose nor by grape PPs . CONCLUSIONS A natural mixture of grape PPs at nutritional doses efficiently prevents fructose-induced oxidative stress and IR . The current interest in grape PP ingredients and products by the global food and nutrition industries could well make them a stepping-stone of preventive nutrition 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 & AIMS Observational studies suggest dietary fructose restriction might lead to sustained symptomatic response in patients with irritable bowel syndrome ( IBS ) and fructose malabsorption . The aims of this study were first to determine whether the efficacy of this dietary change is due to dietary fructose restriction and second to define whether symptom relief was specific to free fructose or to poorly absorbed short-chain carbohydrates in general . METHODS The double-blinded , r and omized , quadruple arm , placebo-controlled rechallenge trial took place in the general community . The 25 patients who had responded to dietary change were provided all food , low in free fructose and fructans , for the duration of the study . Patients were r and omly challenged by grade d dose introduction of fructose , fructans , alone or in combination , or glucose taken as drinks with meals for maximum test period of 2 weeks , with at least 10-day washout period between . For the main outcome measures , symptoms were monitored by daily diary entries and responses to a global symptom question . RESULTS Seventy percent of patients receiving fructose , 77 % receiving fructans , and 79 % receiving a mixture reported symptoms were not adequately controlled , compared with 14 % receiving glucose ( P < or = 0.002 , McNemar test ) . Similarly , the severity of overall and individual symptoms was significantly and markedly less for glucose than other substances . Symptoms were induced in a dose-dependent manner and mimicked previous IBS symptoms . CONCLUSIONS In patients with IBS and fructose malabsorption , dietary restriction of fructose and /or fructans is likely to be responsible for symptomatic improvement , suggesting efficacy is due to restriction of poorly absorbed short-chain carbohydrates in general 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
The results did not show any evidence of publication bias .
CONCLUSION Fructose consumption from industrialized foods has significant effects on most components of metabolic syndrome
OBJECTIVE The aim of this study was to review the current corpus of human studies to determine the association of various doses and duration s of fructose consumption on metabolic syndrome .