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Glycaemic regulation, appetite and ex vivo oxidative stress in young adults following consumption of high-carbohydrate cereal bars fortified with polyphenol-rich berries

  • Tracey J. Smith (a1), James Philip Karl (a1), Marques A. Wilson (a1), Claire C. Whitney (a1), Ann Barrett (a2), Nicole Favreau Farhadi (a2), Chung-Yen Oliver Chen (a3) (a4) and Scott J. Montain (a1)...


Consumption of certain berries appears to slow postprandial glucose absorption, attributable to polyphenols, which may benefit exercise and cognition, reduce appetite and/or oxidative stress. This randomised, crossover, placebo-controlled study determined whether polyphenol-rich fruits added to carbohydrate-based foods produce a dose-dependent moderation of postprandial glycaemic, glucoregulatory hormone, appetite and ex vivo oxidative stress responses. Twenty participants (eighteen males/two females; 24 (sd 5) years; BMI: 27 (sd 3) kg/m2) consumed one of five cereal bars (approximately 88 % carbohydrate) containing no fruit ingredients (reference), freeze-dried black raspberries (10 or 20 % total weight; LOW-Rasp and HIGH-Rasp, respectively) and cranberry extract (0·5 or 1 % total weight; LOW-Cran and HIGH-Cran), on trials separated by ≥5 d. Postprandial peak/nadir from baseline (Δmax) and incremental postprandial AUC over 60 and 180 min for glucose and other biochemistries were measured to examine the dose-dependent effects. Glucose AUC0–180 min trended towards being higher (43 %) after HIGH-Rasp v. LOW-Rasp (P=0·06), with no glucose differences between the raspberry and reference bars. Relative to reference, HIGH-Rasp resulted in a 17 % lower Δmax insulin, 3 % lower C-peptide (AUC0–60 min and 3 % lower glucose-dependent insulinotropic polypeptide (AUC0–180 min) P<0·05. No treatment effects were observed for the cranberry bars regarding glucose and glucoregulatory hormones, nor were there any treatment effects for either berry type regarding ex vivo oxidation, appetite-mediating hormones or appetite. Fortification with freeze-dried black raspberries (approximately 25 g, containing 1·2 g of polyphenols) seems to slightly improve the glucoregulatory hormone and glycaemic responses to a high-carbohydrate food item in young adults but did not affect appetite or oxidative stress responses at doses or with methods studied herein.


Corresponding author

*Corresponding author: T. J. Smith, fax +1 508 233 5833, email


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1. Kirwan, JP, Cyr-Campbell, D, Campbell, WW, et al. (2001) Effects of moderate and high glycemic index meals on metabolism and exercise performance. Metabolism 50, 849855.
2. Kirwan, JP, O’Gorman, D & Evans, WJ (1998) A moderate glycemic meal before endurance exercise can enhance performance. J Appl Physiol 84, 5359.
3. Kirwan, JP, O’Gorman, DJ, Cyr-Campbell, D, et al. (2001) Effects of a moderate glycemic meal on exercise duration and substrate utilization. Med Sci Sports Exerc 33, 15171523.
4. Nilsson, A, Radeborg, K & Bjorck, I (2009) Effects of differences in postprandial glycaemia on cognitive functions in healthy middle-aged subjects. Eur J Clin Nutr 63, 113120.
5. Nilsson, A, Radeborg, K & Bjorck, I (2012) Effects on cognitive performance of modulating the postprandial blood glucose profile at breakfast. Eur J Clin Nutr 66, 10391043.
6. Ludwig, DS (2002) The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. JAMA 287, 24142423.
7. Hanhineva, K, Torronen, R, Bondia-Pons, I, et al. (2010) Impact of dietary polyphenols on carbohydrate metabolism. Int J Mol Sci 11, 13651402.
8. Castro-Acosta, ML, Smith, L, Miller, RJ, et al. (2016) Drinks containing anthocyanin-rich blackcurrant extract decrease postprandial blood glucose, insulin and incretin concentrations. J Nutr Biochem 38, 154161.
9. Castro-Acosta, ML, Stone, SG, Mok, JE, et al. (2017) Apple and blackcurrant polyphenol-rich drinks decrease postprandial glucose, insulin and incretin response to a high-carbohydrate meal in healthy men and women. J Nutr Biochem 49, 5362.
10. Johnston, KL, Clifford, MN & Morgan, LM (2002) Possible role for apple juice phenolic compounds in the acute modification of glucose tolerance and gastrointestinal hormone secretion in humans. J Sci Food Agric 82, 18001805.
11. Nyambe-Silavwe, H & Williamson, G (2016) Polyphenol- and fibre-rich dried fruits with green tea attenuate starch-derived postprandial blood glucose and insulin: a randomised, controlled, single-blind, cross-over intervention. Br J Nutr 116, 443450.
12. Schulze, C, Bangert, A, Kottra, G, et al. (2014) Inhibition of the intestinal sodium-coupled glucose transporter 1 (SGLT1) by extracts and polyphenols from apple reduces postprandial blood glucose levels in mice and humans. Mol Nutr Food Res 58, 17951808.
13. Torronen, R, Kolehmainen, M, Sarkkinen, E, et al. (2012) Postprandial glucose, insulin, and free fatty acid responses to sucrose consumed with blackcurrants and lingonberries in healthy women. Am J Clin Nutr 96, 527533.
14. Torronen, R, Sarkkinen, E, Niskanen, T, et al. (2012) Postprandial glucose, insulin and glucagon-like peptide 1 responses to sucrose ingested with berries in healthy subjects. Br J Nutr 107, 14451451.
15. Williamson, G (2013) Possible effects of dietary polyphenols on sugar absorption and digestion. Mol Nutr Food Res 57, 4857.
16. Chen, CY, Milbury, PE, Lapsley, K, et al. (2005) Flavonoids from almond skins are bioavailable and act synergistically with vitamins C and E to enhance hamster and human LDL resistance to oxidation. J Nutr 135, 13661373.
17. Barrett, A, Ndou, T, Hughey, CA, et al. (2013) Inhibition of alpha-amylase and glucoamylase by tannins extracted from cocoa, pomegranates, cranberries, and grapes. J Agric Food Chem 61, 14771486.
18. Martín, MA, Ramos, S, Mateos, R, et al. (2015) Chemical characterization and chemo-protective activity of cranberry phenolic powders in a model cell culture. Response of the antioxidant defenses and regulation of signaling pathways. Food Res Int 71, 6882.
19. Barrett, AHFN, Fortier, JS & Apostolidis, E (2015) Glucosidase Inhibition Effectiveness of Various Fruit Extracts and Their Acceptance in Performance Bar Products. Institute of Food Technologists Annual Meeting.
20. Wada, L & Ou, B (2002) Antioxidant activity and phenolic content of Oregon caneberries. J Agric Food Chem 50, 34953500.
21. Martín, MA, Ramos, S, Mateos, R, et al. (2015) Chemical characterization and chemo-protective activity of cranberry phenolic powders in a model cell culture. Response of the antioxidant defenses and regulation of signaling pathways. Food Res Int 71, 6882.
22. Gu, J, Ahn-Jarvis, JH, Riedl, KM, et al. (2014) Characterization of black raspberry functional food products for cancer prevention human clinical trials. J Agric Food Chem 62, 39974006.
23. Ceriello, A & Genovese, S (2016) Atherogenicity of postprandial hyperglycemia and lipotoxicity. Rev Endocr Metab Disord 17, 111116.
24. Natella, F, Ghiselli, A, Guidi, A, et al. (2001) Red wine mitigates the postprandial increase of LDL susceptibility to oxidation. Free Radic Biol Med 30, 10361044.
25. Marfella, R, Quagliaro, L, Nappo, F, et al. (2001) Acute hyperglycemia induces an oxidative stress in healthy subjects. J Clin Invest 108, 635636.
26. Chung, BH, Wilkinson, T, Geer, JC, et al. (1980) Preparative and quantitative isolation of plasma lipoproteins: rapid, single discontinuous density gradient ultracentrifugation in a vertical rotor. J Lipid Res 21, 284291.
27. Blundell, J, de Graaf, C, Hulshof, T, et al. (2010) Appetite control: methodological aspects of the evaluation of foods. Obes Rev 11, 251270.
28. Karl, JP, Young, AJ & Montain, SJ (2011) Eating rate during a fixed-portion meal does not affect postprandial appetite and gut peptides or energy intake during a subsequent meal. Physiol Behav 102, 524531.
29. O’Connor, KL, Scisco, JL, Smith, TJ, et al. (2016) Altered appetite-mediating hormone concentrations precede compensatory overeating after severe, short-term energy deprivation in healthy adults. J Nutr 146, 209217.
30. Torronen, R, Sarkkinen, E, Tapola, N, et al. (2010) Berries modify the postprandial plasma glucose response to sucrose in healthy subjects. Br J Nutr 103, 10941097.
31. Kim, DJ, Jeong, YJ, Kwon, JH, et al. (2008) Beneficial effect of chungkukjang on regulating blood glucose and pancreatic beta-cell functions in C75BL/KsJ-db/db mice. J Med Food 11, 215223.
32. Saisho, Y (2016) Postprandial C-peptide to glucose ratio as a marker of β cell function: implication for the management of type 2 diabetes. Int J Mol Sci 17, 744752.
33. Miao, M, Jiang, H, Jiang, B, et al. (2014) Phytonutrients for controlling starch digestion: evaluation of grape skin extract. Food Chem 145, 205211.
34. Oboh, G, Ademosun, A, Olasehinde, T, et al. (2015) Effect of processing methods on the antioxidant properties and inhibition of α-amylase and α-glucosidase by African pear (Dacryodes edulis) fruit. Nutrafoods 14, 1926.
35. Sarikurkcu, C (2015) An alternative antioxidative and enzyme inhibitory agent from Turkey: Robinia pseudoacacia L. Ind Crops Prod 78, 110115.
36. Tong, WY, Wang, H, Waisundara, VY, et al. (2014) Inhibiting enzymatic starch digestion by hydrolyzable tannins isolated from Eugenia jambolana . LWT - Food Sci Technol 59, 389395.
37. Torronen, R, Kolehmainen, M, Sarkkinen, E, et al. (2013) Berries reduce postprandial insulin responses to wheat and rye breads in healthy women. J Nutr 143, 430436.
38. Clegg, ME, Pratt, M, Meade, CM, et al. (2011) The addition of raspberries and blueberries to a starch-based food does not alter the glycaemic response. Br J Nutr 106, 335338.
39. Coe, S & Ryan, L (2016) White bread enriched with polyphenol extracts shows no effect on glycemic response or satiety, yet may increase postprandial insulin economy in healthy participants. Nutr Res 36, 193200.
40. Xu, J, Jönsson, T, Plaza, M, et al. (2018) Probiotic fruit beverages with different polyphenol profiles attenuated early insulin response. Nutr J 17, 3443.
41. Leinonen, K, Liukkonen, K, Poutanen, K, et al. (1999) Rye bread decreases postprandial insulin response but does not alter glucose response in healthy Finnish subjects. Eur J Clin Nutr 53, 262267.
42. Juntunen, KS, Laaksonen, DE, Autio, K, et al. (2003) Structural differences between rye and wheat breads but not total fiber content may explain the lower postprandial insulin response to rye bread. Am J Clin Nutr 78, 957964.
43. Wood, PJ (2007) Cereal β-glucans in diet and health. J Cereal Sci 46, 230238.
44. Pinent, M, Blay, M, Serrano, J, et al. (2017) Effects of flavanols on the enteroendocrine system: repercussions on food intake. Crit Rev Food Sci Nutr 57, 326334.
45. Gruendel, S, Garcia, AL, Otto, B, et al. (2006) Carob pulp preparation rich in insoluble dietary fiber and polyphenols enhances lipid oxidation and lowers postprandial acylated ghrelin in humans. J Nutr 136, 15331538.
46. Serrano, J, Casanova-Marti, A, Depoortere, I, et al. (2016) Subchronic treatment with grape-seed phenolics inhibits ghrelin production despite a short-term stimulation of ghrelin secretion produced by bitter-sensing flavanols. Mol Nutr Food Res 60, 25542564.
47. Serrano, J, Casanova-Marti, A, Gil-Cardoso, K, et al. (2016) Acutely administered grape-seed proanthocyanidin extract acts as a satiating agent. Food Funct 7, 483490.
48. Gruendel, S, Garcia, AL, Otto, B, et al. (2007) Increased acylated plasma ghrelin, but improved lipid profiles 24-h after consumption of carob pulp preparation rich in dietary fibre and polyphenols. Br J Nutr 98, 11701177.
49. Gruendel, S, Otto, B, Garcia, AL, et al. (2007) Carob pulp preparation rich in insoluble dietary fibre and polyphenols increases plasma glucose and serum insulin responses in combination with a glucose load in humans. Br J Nutr 98, 101105.
50. Wanders, AJ, van den Borne, JJ, de Graaf, C, et al. (2011) Effects of dietary fibre on subjective appetite, energy intake and body weight: a systematic review of randomized controlled trials. Obes Rev 12, 724739.
51. Shin, HS, Kindleysides, S, Yip, W, et al. (2015) Postprandial effects of a polyphenolic grape extract (PGE) supplement on appetite and food intake: a randomised dose-comparison trial. Nutr J 14, 96104.
52. Yilmazer-Musa, M, Griffith, AM, Michels, AJ, et al. (2012) Grape seed and tea extracts and catechin 3-gallates are potent inhibitors of alpha-amylase and alpha-glucosidase activity. J Agric Food Chem 60, 89248929.
53. Panickar, KS (2013) Effects of dietary polyphenols on neuroregulatory factors and pathways that mediate food intake and energy regulation in obesity. Mol Nutr Food Res 57, 3447.
54. Sies, H, Stahl, W & Sevanian, A (2005) Nutritional, dietary and postprandial oxidative stress. J Nutr 135, 969972.
55. Cassidy, A & Minihane, AM (2017) The role of metabolism (and the microbiome) in defining the clinical efficacy of dietary flavonoids. Am J Clin Nutr 105, 1022.
56. Neveu, V, Perez-Jimenez, J, Vos, F, et al. (2010) Phenol-Explorer: an online comprehensive database on polyphenol contents in foods. Database 2010, bap024.
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