Effects of dietary fructose on plasma lipids in healthy subjects. Exercise performed immediately after fructose ingestion enhances fructose oxidation and suppresses fructose storage. The ingestion of a fructose-containing beverage combined with fat cream exacerbates postprandial lipidemia in young healthy women. Consumption of fructose-sweetened beverages for 10 weeks reduces net fat oxidation and energy expenditure in overweight/obese men and women
BACKGROUND About 9 % of average dietary energy intake in the United States comes from fructose . Such a high consumption raises concern about the metabolic effects of this sugar . OBJECTIVE The objective of this study was to determine the effect of dietary fructose on plasma lipids . DESIGN The study was conducted in the General Clinical Research Center at Fairview-University of Minnesota Medical Center . The participants were 24 healthy adult volunteers ( 12 men and 12 women ; 6 of each sex were aged < 40 y and 6 of each sex were aged > /=40 y ) . All subjects received 2 isoenergetic study diets assigned by using a r and omized , balanced crossover design . One diet provided 17 % of energy as fructose . The other diet was sweetened with glucose and was nearly devoid of fructose . Each diet was fed for 6 wk . Both diets were composed of common foods and contained nearly identical amounts of carbohydrate , protein , fat , fiber , cholesterol , and saturated , monounsaturated , and polyunsaturated fatty acids . All meals were prepared in the metabolic kitchen of the General Clinical Research Center . RESULTS The responses to the study diets differed by sex . In men , the fructose diet produced significantly higher fasting , postpr and ial , and daylong plasma triacylglycerol concentrations than did the glucose diet . The daylong plasma triacylglycerol concentration after 6 wk of the fructose diet was 32 % greater in men than the corresponding concentration during the glucose diet ( P : < 0.001 ) . The fructose diet had no significant effect on fasting or postpr and ial plasma triacylglycerol concentrations in women . The fructose diet also had no persistent effect on fasting plasma cholesterol , HDL cholesterol , or LDL cholesterol in either men or women . CONCLUSIONS Dietary fructose was associated with increased fasting and postpr and ial plasma triacylglycerol concentrations in men . Diets high in added fructose may be undesirable , particularly for men . Glucose may be a suitable replacement sugar 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 AIM To investigate the acute effects of the ingestion of a fructose-containing beverage combined with fat on postpr and ial lipoprotein metabolism . METHODS Twelve young healthy Japanese women with apolipoprotein E phenotype 3/3 were enrolled in this study . At each of four sessions , the subjects ingested one of four sugar beverages containing fructose and /or glucose ( total : 0.5 g/kg body weight ) combined with OFTT cream ( 1 g/kg , 0.35 g/kg as fat ) in a r and omized crossover design . The four sugar beverages were as follows : 100 % ( w/w ) fructose ( F100 ) , 90 % fructose + 10 % glucose ( F90G10 ) , 55 % fructose + 45 % glucose ( F55G45 ) and 100 % glucose ( G100 ) . Venous blood sample s were obtained at baseline and 0.5 , one , two , four and six hours after ingestion . RESULTS The serum concentrations of TG in the F100 , F90G10 and F55G45 trials were significantly higher than each fasting value at two and four hours , and returned to baseline at six hours , except in the F100 trial . The concentrations at four hours and the incremental areas under the curve for the hepatic triglyceride-rich lipoprotein-triglyceride ( VLDL-TG(TM ) ) levels in the F100 and F90G10 trials were significantly higher and larger , respectively , than those observed in the G100 trial . Meanwhile , the concentrations of RLP-TG and apolipoprotein B-48 peaked at two hours in the G100 trial , versus four hours in the other trials , and did not return to baseline at six hours , except in the G100 trial . At four hours , the ⊿apoB48 tended to be higher in the F100 trial than in the G100 trial . CONCLUSIONS The ingestion of a high-fructose-containing beverage with fat cream delays the clearance of chylomicron and its remnant derived from the intestine and enhances the secretion of triglyceride-rich lipoprotein particles from the liver , thereby inducing postpr and ial lipidemia , even in young healthy women 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
Pooled analyses show that fructose in isocaloric exchange for other carbohydrate does not increase postpr and ial triglycerides , although an effect can not be excluded under all conditions .
Fructose providing excess energy does increase postpr and ial triglycerides .
BACKGROUND In the absence of consistent clinical evidence , concerns have been raised that  fructose  raises postpr and ial triglycerides .
PURPOSE A systematic review and meta- analysis was conducted to assess the effect of  fructose on postpr and ial triglycerides .