Add Bilberries are Rich in Anthocyanins

Bilberries-are-Rich-in-Anthocyanins.md

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+<br>The present study shows that the ingestion of a capsule containing concentrated bilberry extract gives a reduced postprandial glycaemic response in volunteers with T2D controlled by diet and lifestyle alone compared with an inert placebo capsule. Given that the glucose concentrations between the volunteers taking the bilberry and control extract are different during the later time points (120, 150 and 180 min) it might be suggested that the active ingredient takes some time before it has an effect, perhaps due to digestion or where it is having its effect, for example, time to reach the gastrointestinal tract. This differs from previous studies in normal/healthy volunteers where the decrease in the plasma glucose between the volunteers taking the berries and control extract occurs at the earlier time points( Reference Törrönen, Sarkkinen and Tapola 23 , Reference Johnston, Clifford and Morgan 29 , Reference Törrönen, Sarkkinen and Niskanen 30 ). This may be due to differences in glucose metabolism in volunteers with T2D or differences between the studies, for example, the ingestion of a capsule may take longer to reach the gastrointestinal tract compared with a berry purée.<br>
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+<br>The bilberry extract also decreased plasma insulin compared with the control in a profile that mirrors the postprandial glycaemic response. One explanation is that the decreased plasma insulin is a result of the lower plasma glucose or the volunteers become more insulin sensitive. One study in normal/healthy volunteers that reported a mean decrease in plasma glucose after 15 and 30 min following the consumption of a commercial apple juice also observed parallel changes in the plasma concentrations of the incretins, GLP-1 and GIP( Reference Johnston, Clifford and Morgan 29 ). Both these incretins are produced in the intestinal mucosa and are normally secreted when food is eaten in order to reduce glycaemic excursion by causing an increase in insulin secretion. However, GLP-1 also has other effects such as inhibiting glucagon secretion from the pancreas and by decreasing the time it takes for food to empty from the stomach. In the present study we did not find an effect of the bilberry extract on GIP, GLP-1 or glucagon.<br>
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+<br>Further, we also looked at the effect of the bilberry extract on the pancreatic hormone amylin which also affects plasma glucose concentration independent of insulin secretion. Again, we did not observe any effects of the bilberry extract on plasma amylin compared with the placebo. Bilberries are rich in anthocyanins, recognised for their ability to provide and activate cellular antioxidant protection, inhibit inflammatory gene expression, and consequently protect against oxidant-induced and inflammatory cell damage and cytotoxicity( Reference Zafra-Stone, Yasmin and Bagchi 2 - Reference Neto 4 ). In light of this we investigated the effects of a bilberry extract on the inflammatory marker MCP-1 that plays a role in the recruitment of monocytes due to the low-grade inflammation associated with obesity( Reference Panee 31 ). However, in the present study we did not see any changes in plasma levels of MCP-1 due to the ingestion of the bilberry extract compared with the control.<br>
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+<br>Similarly, we could not detect any alterations in plasma TEAC or FRAP, both markers of oxidation. It may well be that any effects of the bilberry extract on markers of inflammation and oxidation take longer than 5 h to occur. In addition, our sample size of eight volunteers was modest, and meant that we had 80 % power to detect treatment effects about 1.5 times the natural within-individual variability (sd) in outcome measurements. Therefore any negative results reported need to be viewed in this context. It has been suggested that berry polyphenols inhibit α-glycosidase, the enzyme responsible for the digestion of sucrose to glucose in the intestinal epithelium. Two anthocyanins (cyanidin-3-rutinoside( Reference Adisakwattana, Ngamrojanavanich and Kalampakorn 32 ) and  [MedicGLP Official](http://cgi.www5b.biglobe.ne.jp/~akanbe/yu-betsu/joyful/joyful.cgi?page=20) cyanidin-3-galactoside( Reference Akkarachiyasit, Yibchok-Anun and Wacharasindhu 33 , Reference Adisakwattana, Charoenlertkul and Yibchok-Anun 34 )) have been shown in vitro to be [inhibitors](https://search.un.org/results.php?query=inhibitors) of α-glucosidase. Cyanidin-3-galactoside is present in bilberries( Reference Buchert, Koponen and Suutarinen 35 ) and cranberries( Reference Wilson, Singh and Vorsa 24 ), and has shown a synergistic effect with acarbose( Reference Adisakwattana, Charoenlertkul and Yibchok-Anun 34 ). Acarbose is used as an inhibitor of α-glucosidase in the treatment of diabetes.<br>
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+<br>Also proanthocyanidins have shown potent α-glucosidase inhibitory activity( Reference Schäfer and Högger 36 , Reference Kumar, Narwal and Kumar 37 ). The anthocyanins in the bilberry extract are well documented(38,39) and include both cyanidin-3-galactoside and proanthocyanidins. As the glucose load Polycal used here for the OGTT is composed of complex carbohydrates, the reduced postprandial glycaemia in response to the ingestion of the bilberry extract may be due in part to a reduction in the breakdown of carbohydrates. In addition there is evidence that polyphenols can affect the absorption of glucose across the intestine. SGLT1-mediated glucose uptake appears to be inhibited by several phenolic acids (for example, chlorogenic, ferulic and caffeic acids)( Reference Welsch, Lachance and Wasserman 13 ) as well as by glucosides of quercetin( Reference Cermak, Landgraf and Wolffram 20 ). The glucose transport by GLUT2 was inhibited by the flavonols quercetin and myricetin( Reference Song, Kwon and Chen 19 ,  [weight support supplement](https://rentry.co/47026-glp-weight-loss-a-revolutionary-approach-to-obesity-management) Reference Johnston, Sharp and Clifford 21 ). These phenolic acids and flavonols with inhibitory activity against intestinal glucose uptake are common polyphenolic constituents of berries( Reference Määttä-Riihinen, Kamal-Eldin and Mattila 41 - Reference Mattila, Hellström and Törrönen 43 ). Thus, both a reduced breakdown of carbohydrates and lowered intestinal absorption may contribute to the improved glycaemic excursion.<br>