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1.
Fructose Metabolism in Cancer.
Krause, N, Wegner, A
Cells. 2020;(12)
Abstract
The interest in fructose metabolism is based on the observation that an increased dietary fructose consumption leads to an increased risk of obesity and metabolic syndrome. In particular, obesity is a known risk factor to develop many types of cancer and there is clinical and experimental evidence that an increased fructose intake promotes cancer growth. The precise mechanism, however, in which fructose induces tumor growth is still not fully understood. In this article, we present an overview of the metabolic pathways that utilize fructose and how fructose metabolism can sustain cancer cell proliferation. Although the degradation of fructose shares many of the enzymes and metabolic intermediates with glucose metabolism through glycolysis, glucose and fructose are metabolized differently. We describe the different metabolic fates of fructose carbons and how they are connected to lipogenesis and nucleotide synthesis. In addition, we discuss how the endogenous production of fructose from glucose via the polyol pathway can be beneficial for cancer cells.
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2.
Effect of fructose and its epimers on postprandial carbohydrate metabolism: A systematic review and meta-analysis.
Braunstein, CR, Noronha, JC, Khan, TA, Mejia, SB, Wolever, TM, Josse, RG, Kendall, CW, Sievenpiper, JL
Clinical nutrition (Edinburgh, Scotland). 2020;(11):3308-3318
Abstract
AIMS: To synthesize the evidence of the effect of small doses (≤30-g/meal) of fructose and its epimers (allulose, tagatose, and sorbose) on the postprandial glucose and insulin response to carbohydrate-containing meals. METHODS MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through to April 9, 2019. We included randomized (RCTs) and non-randomized acute, single-meal, controlled feeding trials that added ≤30-g of fructose or its epimers either prior to or with a carbohydrate-containing meal compared with the same meal alone. Outcomes included the incremental area under the curve (iAUC) for glucose and insulin, the Matsuda Insulin Sensitivity Index, and the Early Insulin Secretion Index. Data were expressed as ratio of means (RoM) with 95% CIs and pooled using the inverse variance method. The overall certainty of the evidence was evaluated using GRADE. RESULTS Forty trial comparisons (n = 400) were included (none for sorbose). Allulose significantly reduced the postprandial iAUC glucose response by 10% (0.90 [0.84 to 0.96], P < 0.01). Tagatose significantly reduced the postprandial iAUC insulin response by 25% (0.75 [0.62 to 0.91], P < 0.01) and showed a non-significant 3% reduction in the postprandial iAUC glucose response (0.97 [0.94 to 1.00], P = 0.07). There was no effect of fructose on any outcome. The certainty of the evidence was graded as low to moderate for fructose, moderate for allulose, and low for tagatose. CONCLUSIONS Small doses of allulose and tagatose, but not fructose, lead to modest improvements on postprandial glucose and insulin regulation. There is a need for long-term RCTs to confirm the sustainability of these improvements.
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3.
Pectin-Alginate Does Not Further Enhance Exogenous Carbohydrate Oxidation in Running.
Barber, JFP, Thomas, J, Narang, B, Hengist, A, Betts, JA, Wallis, GA, Gonzalez, JT
Medicine and science in sports and exercise. 2020;(6):1376-1384
Abstract
PURPOSE Maximizing carbohydrate availability is important for many endurance events. Combining pectin and sodium alginate with ingested maltodextrin-fructose (MAL + FRU + PEC + ALG) has been suggested to enhance carbohydrate delivery via hydrogel formation, but the influence on exogenous carbohydrate oxidation remains unknown. The primary aim of this study was to assess the effects of MAL + FRU + PEC + ALG on exogenous carbohydrate oxidation during exercise compared with a maltodextrin-fructose mixture (MAL + FRU). MAL + FRU has been well established to increase exogenous carbohydrate oxidation during cycling compared with glucose-based carbohydrates (MAL + GLU). However, much evidence focuses on cycling, and direct evidence in running is lacking. Therefore, a secondary aim was to compare exogenous carbohydrate oxidation rates with MAL + FRU versus MAL + GLU during running. METHODS Nine trained runners completed two trials (MAL + FRU and MAL + FRU + PEC + ALG) in a double-blind, randomized crossover design. A subset (n = 7) also completed a MAL + GLU trial to address the secondary aim, and a water trial to establish background expired CO2 enrichment. Participants ran at 60% V˙O2peak for 120 min while ingesting either water only or carbohydrate solutions at a rate of 1.5 g carbohydrate per minute. RESULTS At the end of 120 min of exercise, exogenous carbohydrate oxidation rates were 0.9 (SD 0.5) g·min with MAL + GLU ingestion. MAL + FRU ingestion increased exogenous carbohydrate oxidation rates to 1.1 (SD 0.3) g·min (P = 0.038), with no further increase with MAL + FRU + PEC + ALG ingestion (1.1 (SD 0.3) g·min; P = 1.0). No time-treatment interaction effects were observed for plasma glucose, lactate, insulin, or nonesterified fatty acids, or for ratings of perceived exertion or gastrointestinal symptoms (all, P > 0.05). CONCLUSION To maximize exogenous carbohydrate oxidation during moderate-intensity running, athletes may benefit from consuming glucose(polymer)-fructose mixtures over glucose-based carbohydrates alone, but the addition of pectin and sodium alginate offers no further benefit.
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4.
A new understanding: Gene expression, cell characteristic and antioxidant enzymes of Zygosaccharomyces rouxii under the D-fructose regulation.
Liu, H, Dai, L, Wang, F, Li, X, Liu, W, Pan, B, Wang, C, Zhang, D, Deng, J, Li, Z
Enzyme and microbial technology. 2020;:109409
Abstract
Zygosaccharomyces rouxii is a well-known salt-tolerant yeast. In our previous study, it was interesting that Z. rouxii could produce higher levels of 4-hydroxy-2, 5-dimethyl-3(2 H)-furanone in 120 g/L D-fructose and 180 g/L NaCl involved YPD medium at 5 d. In order to explore the resistance and furanone production mechanisms of Z. rouxii under D-fructose regulation, a comparative transcriptomics method in Z. rouxii was to set to find differentially expressed genes, the physiological and biochemical indexes (growth and cell morphology, lipid peroxidation and relative electrical conductivity, the antioxidant enzymes activity), and the expression of oxidoreductase activity genes. The results indicated that a larger number of different expressed genes at transcriptome analysis, such as the series antioxidant enzymes were related to the resistance characteristics. Research had confirmed that the living cell numbers and cell areas of D-fructose regulation group were significantly lower than the controls at the initial stage, while those higher than of the controls at the late stage. During the fermentation period, the lipid peroxidation and the relative electrical conductivity of the yeast cell membrane were increased. And also the D-fructose regulation group present lower inhibition superoxide anion ability. The activity of CAT in the D-fructose regulation group was always higher than that of the control group. Only the activity of GSH-Px was found to be significantly increased at 1 d except for other enzymes activities. Most of the oxidoreductase activity genes, such as especially the GSH-Px gene under D-fructose regulation conditions were expressed at higher levels than those of control groups. Combining the levels of transcription and enzymes activity data, those could understand that exogenous D-fructose had a stress effect on Z. rouxii at the early stage of culture. With the fermentation time progress, it was no longer a stressor substance for the Z. rouxii, and changed the nutrient to promote growth of Z. rouxii in the later stages. During the whole process, GSH-Px was the main defense enzyme and CAT was the sustained defense enzyme. Therefore, the experimental results might provide effective mechanisms in Z. rouxii for practical application of furanone production in the industry under exogenous D-fructose regulation.
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5.
Fructose vs glucose decreased liking/wanting and subsequent intake of high-energy foods in young women.
Ao, H, Li, J, Li, O, Su, M, Gao, X
Nutrition research (New York, N.Y.). 2020;:60-71
Abstract
Recent research on the health impacts of added sugar has prompted the comparison of the effects of its 2 major components: glucose and fructose. Fructose was identified as a risk factor for obesity and metabolic syndrome. However, because of the differences in metabolic responses and responsivity of reward circuitry to palatable food, it is unknown if glucose and fructose induce similar appetite-related responses in humans with varying weights. This study compared the behavioral responses to food in young women of a healthy weight (n = 31) and with excess weight (n = 28). We hypothesized that (1) the inhibitory effect of glucose (vs fructose) on food-related responses would be greater in subjects of a healthy weight than in those with overweight/obesity and (2) subjects with overweight/obesity would exhibit a stronger preference for food than subjects with a healthy weight. After an overnight fast, the subjects ingested a glucose or equienergetic fructose beverage on 2 separate days, respectively. Then, they completed liking and wanting ratings and 2 decision-making tasks followed by ad libitum food intake. The results revealed that fructose reduced both liking and wanting for food in subjects with overweight/obesity and also decreased energy intake in all subjects. Relative to the healthy-weight group, subjects with overweight/obesity preferred the immediate reward. Moreover, only in the healthy-weight group were liking and wanting scores for food positively associated with actual food consumption. Overall, fructose (vs glucose) showed an acute inhibitory effect on appetite-related responses in subjects with excess weight.
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6.
Synergistic effects of fructose and glucose on lipoprotein risk factors for cardiovascular disease in young adults.
Hieronimus, B, Medici, V, Bremer, AA, Lee, V, Nunez, MV, Sigala, DM, Keim, NL, Havel, PJ, Stanhope, KL
Metabolism: clinical and experimental. 2020;:154356
Abstract
BACKGROUND Fructose consumption increases risk factors for cardiometabolic disease. It is assumed that the effects of free sugars on risk factors are less potent because they contain less fructose. We compared the effects of consuming fructose, glucose or their combination, high fructose corn syrup (HFCS), on cardiometabolic risk factors. METHODS Adults (18-40 years; BMI 18-35 kg/m2) participated in a parallel, double-blinded dietary intervention during which beverages sweetened with aspartame, glucose (25% of energy requirements (ereq)), fructose or HFCS (25% and 17.5% ereq) were consumed for two weeks. Groups were matched for sex, baseline BMI and plasma lipid/lipoprotein concentrations. 24-h serial blood samples were collected at baseline and at the end of intervention. Primary outcomes were 24-h triglyceride AUC, LDL-cholesterol (C), and apolipoprotein (apo)B. Interactions between fructose and glucose were assessed post hoc. FINDINGS 145 subjects (26.0 ± 5.8 years; body mass index 25.0 ± 3.7 kg/m2) completed the study. As expected, the increase of 24-h triglycerides compared with aspartame was highest during fructose consumption (25%: 6.66 mmol/Lx24h 95% CI [1.90 to 11.63], P = 0.0013 versus aspartame), intermediate during HFCS consumption (25%: 4.68 mmol/Lx24h 95% CI [-0.18 to 9.55], P = 0.066 versus aspartame) and lowest during glucose consumption. In contrast, the increase of LDL-C was highest during HFCS consumption (25%: 0.46 mmol/L 95% CI [0.16 to 0.77], P = 0.0002 versus aspartame) and intermediate during fructose consumption (25%: 0.33 mmol/L 95% CI [0.03 to 0.63], P = 0.023 versus aspartame), as was the increase of apoB (HFCS-25%: 0.108 g/L 95%CI [0.032 to 0.184], P = 0.001; fructose 25%: 0.072 g/L 95%CI [-0.004 to 0.148], P = 0.074 versus aspartame). The post hoc analyses showed significant interactive effects of fructose*glucose on LDL-C and apoB (both P < 0.01), but not on 24-h triglyceride (P = 0.340). CONCLUSION A significant interaction between fructose and glucose contributed to increases of lipoprotein risk factors when the two monosaccharides were co-ingested as HFCS. Thus, the effects of HFCS on lipoprotein risks factors are not solely mediated by the fructose content and it cannot be assumed that glucose is a benign component of HFCS. Our findings suggest that HFCS may be as harmful as isocaloric amounts of pure fructose and provide further support for the urgency to implement strategies to limit free sugar consumption.
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7.
A Single Load of Fructose Attenuates the Risk of Exercise-Induced Hypoglycemia in Adults With Type 1 Diabetes on Ultra-Long-Acting Basal Insulin: A Randomized, Open-Label, Crossover Proof-of-Principle Study.
Kosinski, C, Herzig, D, Laesser, CI, Nakas, CT, Melmer, A, Vogt, A, Vogt, B, Laimer, M, Bally, L, Stettler, C
Diabetes care. 2020;(9):2010-2016
Abstract
OBJECTIVE While the adjustment of insulin is an established strategy to reduce the risk of exercise-associated hypoglycemia for individuals with type 1 diabetes, it is not easily feasible for those treated with ultra-long-acting basal insulin. The current study determined whether pre-exercise intake of fructose attenuates the risk of exercise-induced hypoglycemia in individuals with type 1 diabetes using insulin degludec. RESEARCH DESIGN AND METHODS Fourteen male adults with type 1 diabetes completed two 60-min aerobic cycling sessions with or without prior intake (30 min) of 20 g of fructose, in a randomized two-period crossover design. Exercise was performed in the morning in a fasted state without prior insulin reduction and after 48 h of standardized diet. The primary outcome was time to hypoglycemia (plasma glucose ≤3.9 mmol/L) during exercise. RESULTS Intake of fructose resulted in one hypoglycemic event at 60 min compared with six hypoglycemic events at 27.5 ± 9.4 min of exercise in the control condition, translating into a risk reduction of 87.8% (hazard ratio 0.12 [95% CI 0.02, 0.66]; P = 0.015). Mean plasma glucose during exercise was 7.3 ± 1.4 mmol/L with fructose and 5.5 ± 1.1 mmol/L in the control group (P < 0.001). Lactate levels were higher at rest in the 30 min following fructose intake (P < 0.001) but were not significantly different from the control group during exercise (P = 0.32). Substrate oxidation during exercise did not significantly differ between the conditions (P = 0.73 for carbohydrate and P = 0.48 for fat oxidation). Fructose was well tolerated. CONCLUSIONS Pre-exercise intake of fructose is an easily feasible, effective, and well-tolerated strategy to alleviate the risk of exercise-induced hypoglycemia while avoiding hyperglycemia in individuals with type 1 diabetes on ultra-long-acting insulin.
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8.
Effectiveness of vitamin D supplementation in Swedish children may be negatively impacted by BMI and serum fructose.
McClorry, S, Slupsky, CM, Lind, T, Karlsland Åkeson, P, Hernell, O, Öhlund, I
The Journal of nutritional biochemistry. 2020;:108251
Abstract
In regions where sunlight exposure is limited, dietary vitamin D intake becomes important for maintaining status. However, Swedish children have been shown to have deficient or marginal status during the winter months even if the recommended dietary intake is met. Since low vitamin D status has been associated with several disease states, this study investigated the metabolic changes associated with improved vitamin D status due to supplementation. During the 3 winter months, 5-7-year-old children (n=170) in northern (Umeå, 63° N) and southern (Malmö, 55° N) Sweden were supplemented daily with 2 (placebo), 10 or 25 μg of vitamin D. BMI-for-age z-scores (BAZ), S-25(OH)D concentrations, insulin concentrations and the serum metabolome were assessed at baseline and follow-up. S-25(OH)D concentrations increased significantly in both supplementation groups (P<.001). Only arginine and isopropanol concentrations exhibited significant associations with improvements in S-25(OH)D. Furthermore, the extent to which S-25(OH)D increased was correlated with a combination of baseline BAZ and the change in serum fructose concentrations from baseline to follow up (P=.012). In particular, the change in S-25(OH)D concentrations was negatively correlated (P=.030) with the change in fructose concentrations for subjects with BAZ ≥0 and consuming at least 20 μg vitamin D daily. These results suggest that although the metabolic changes associated with improved vitamin D status are small, the effectiveness of dietary supplementation may be influenced by serum fructose concentrations.
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9.
Consumption of sugar sweetened beverages and dietary fructose in relation to risk of gout and hyperuricemia: a systematic review and meta-analysis.
Ebrahimpour-Koujan, S, Saneei, P, Larijani, B, Esmaillzadeh, A
Critical reviews in food science and nutrition. 2020;(1):1-10
Abstract
Background: Findings on the association of sugar sweetened beverages (SSB) and fructose intakes with gout and hyperuricemia have been conflicting.Objective: We aimed to perform a systematic review and meta-analysis on studies that examined the association of SSB and fructose consumption with gout and hyperuricemia in adults.Methods: We searched PubMed, Scopus and Google Scholar up to Aug 2017 for all relevant published papers assessing SSB and fructose intakes and risk of gout and hyperuricemia. After excluding non-relevant papers, 10 studies remained in our systematic. Meta-analysis on SSB consumption and risk of gout was done on three effect sizes from cohort studies and five effect sizes from case-control studies. For risk of hyperuricemia, the meta-analysis was done on six effect sizes from cross-sectional studies. All analyses were performed on ORs or RRs.Results: We found an overall significant positive association between SSB consumption and risk of gout in both cohort (summary effect size: 1.35; 95% CI: 1.18-1.55) and case-control studies (summary effect size: 1.33; 95% CI: 1.06-1.66). Meta-analysis on cross-sectional studies revealed that SSB consumption was associated with 35% greater odds of hyperuricemia (summary effect size: 1.35; 95% CI: 1.19-1.52). No evidence of between-study heterogeneity as well as publication bias was found. Although the studies on fructose intake and risk of gout and hyperuricemia were included in our systematic review, we did not perform met-analysis on these studies due to insufficient number of publications.Conclusion: We found that SSB consumption was significantly associated with increased risk of gout and hyperuricemia in adult population. Further studies are needed to examine the association between dietary fructose intake and risk of gout and hyepruricemia.
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10.
Effects of low fructose diet on glycemic control, lipid profile and systemic inflammation in patients with type 2 diabetes: A single-blind randomized controlled trial.
Jalilvand, A, Behrouz, V, Nikpayam, O, Sohrab, G, Hekmatdoost, A
Diabetes & metabolic syndrome. 2020;(5):849-855
Abstract
BACKGROUND AND AIM Type 2 diabetes is one of the global epidemic disorders, which causes many side effects on the body. Fructose is a lipogenic monosaccharide. Recent studies have reported the adverse effects of this carbohydrate on diabetes. This study aimed to evaluate the clinical efficacy of a low-fructose diet on the metabolic alterations in patients with type 2 diabetes. METHODS This study was a randomized, single-blind clinical trial on 50 patients with type 2 diabetes. Participants randomly allocated to two groups, to receive either diabetic-diet or diabetic-diet with low-fructose for 8-weeks. Anthropometric measurements, systolic blood pressure (SBP), Diastolic blood pressure (DBP) and metabolic factors were assessed at baseline and the end of the trial. RESULTS At the end of trial, reduction in body weight, waist circumference, and blood pressure were not significant except for DBP (P = 0.013). Statistical analysis showed that low-fructose diet compared to control group significantly declined fasting blood glucose (FBG), Hemoglobin A1c (HbA1c), Triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C) and high-sensitivity C-reactive protein (hs-CRP) (P = 0.015, P = 0.001, P=<0.0001, P= <0.0001 and P= <0.0001 respectively). CONCLUSION Our results showed that eight weeks of low-fructose diet results in a significant improvement in FBG, HbA1c, TG, HDL-C and hs-CRP in patients with type 2 diabetes.