Postprandial glucose, insulin and glucagon-like peptide 1 responses to sucrose ingested with berries in healthy subjects.

Berries are often consumed with sucrose. They are also rich sources of polyphenols which may modulate glycaemia after carbohydrate ingestion. The present study investigated the postprandial glucose, insulin and glucagon-like peptide 1 (GLP-1) responses to sucrose ingested with berries, in comparison with a similar sucrose load without berries. A total of twelve healthy subjects were recruited to a randomised, single-blind, placebo-controlled crossover study. They participated in two meal tests on separate days. The berry meal was a purée (150 g) made of bilberries, blackcurrants, cranberries and strawberries with 35 g sucrose. The control meal included the same amount of sucrose and available carbohydrates in water. Fingertip capillary and venous blood samples were taken at baseline and at 15, 30, 45, 60, 90 and 120 min after starting to eat the meal. Glucose, insulin and GLP-1 concentrations were determined from the venous samples, and glucose also from the capillary samples. Compared to the control meal, ingestion of the berry meal resulted in lower capillary and venous plasma glucose and serum insulin concentrations at 15 min (P = 0·021, P < 0·007 and P = 0·028, respectively), in higher concentrations at 90 min (P = 0·028, P = 0·021 and P = 0·042, respectively), and in a modest effect on the GLP-1 response (P = 0·05). It also reduced the maximum increases of capillary and venous glucose and insulin concentrations (P = 0·009, P = 0·011 and P = 0·005, respectively), and improved the glycaemic profile (P < 0·001 and P = 0·003 for capillary and venous samples, respectively). These results suggest that the glycaemic control after ingestion of sucrose can be improved by simultaneous consumption of berries.

Antiaggregation potential of berry fractions against pairs of Streptococcus mutans with Fusobacterium nucleatum or Actinomyces naeslundii.

Coaggregation is an interspecies adhesion process, which is essential to the development of dental plaque. This is an in vitro study of the composition of the soluble solids in the berry juice molecular size fractions (<10 kDa, FI; 10-100 kDa, FII; >100 kDa, FIII) derived from apple, bilberry, blackcurrant, cloudberry, crowberry and lingonberry and their ability to inhibit and reverse coaggregation of the pairs of common species in dental plaque: Streptococcus mutans with Fusobacterium nucleatum or Actinomyces naeslundii. Inhibitory and reversal activity was found in the molecular size fractions FII and FIII of bilberry, blackcurrant, crowberry and lingonberry. The active fractions contained higher amounts of polyphenols (5-12% of soluble solids) than those without activity (<2% of soluble solids). Proanthocyanidins dominated in the active lingonberry juice fractions FII and FIII and also small amounts of anthocyanins were detected. Anthocyanins, proanthocyanidins and flavonol glycosides were prevalent in FII and FIII fractions of bilberry, blackcurrant and crowberry juices. Comparable amounts of sugars and titratable acids were present in the latter three berry juice fractions of different size. The results indicate that the high molecular size fractions of lingonberry, bilberry, blackcurrant and crowberry juices have antiaggregation potential on common oral bacteria, the potential being associated with their polyphenolic content.

Three Nordic berries inhibit intestinal tumorigenesis in multiple intestinal neoplasia/+ mice by modulating beta-catenin signaling in the tumor and transcription in the mucosa.

Berries contain a number of compounds that are proposed to have anticarcinogenic properties. We studied the effects and molecular mechanisms of wild berries with different phenolic profiles on intestinal tumorigenesis in multiple intestinal neoplasia/+ mice. The mice were fed a high-fat AIN93-G diet (Con) or AIN93-G diets containing 10% (w:w) freeze-dried bilberry, lingonberry (LB), or cloudberry (CB) for 10 wk. All 3 berries significantly inhibited the formation of intestinal adenomas as indicated by a 15-30% reduction in tumor number (P < 0.05). CB and LB also reduced tumor burden by over 60% (P < 0.05). Compared to Con, CB and LB resulted in a larger (P < 0.05) proportion of small adenomas (43, 69, and 64%, respectively) and a smaller proportion of large adenomas (56, 29, and 33%, respectively). Beta-catenin and cyclin D1 in the small and large adenomas and in the normal-appearing mucosa were measured by Western blotting and immunohistochemistry. CB resulted in decreased levels of nuclear beta-catenin and cyclin D1 and LB in the level of cyclin D1 in the large adenomas (P < 0.05). Early changes in gene expression in the normal-appearing mucosa were analyzed by Affymetrix microarrays, which revealed changes in genes implicated in colon carcinogenesis, including the decreased expression of the adenosine deaminase, ecto-5'-nucleotidase, and prostaglandin E2 receptor subtype EP4. Our results indicate that berries are potentially a rich source of chemopreventive components.

Phenolic acids in berries, fruits, and beverages.

The contents of soluble and total phenolic acids were analyzed in samples of 29 berries and berry products, 24 fruits and fruit peels, and 12 beverages. Variation of phenolic acids in berries was also studied. Soluble phenolic acids were extracted with methanolic acetic acid, and a tentative quantification was performed by high-performance liquid chromatography (HPLC). The total phenolic acid content was determined by HPLC after alkaline and acid hydrolyses. The content of total phenolic acids as aglycones in the above samples varied from 0 (pear cider) to 103 mg/100 g fresh weight (rowanberry). Besides rowanberry, the best phenolic acid sources among berries were chokeberry (96 mg/100 g), blueberry (85 mg/100 g), sweet rowanberry (75 mg/100 g), and saskatoon berry (59 mg/100 g). Among fruits, the highest contents (28 mg/100 g) were determined in dark plum, cherry, and one apple variety (Valkea Kuulas). Coffee (97 mg/100 g) as well as green and black teas (30-36 mg/100 g) were the best sources among beverages. Caffeic acid dominated in all of these samples except in tea brews. Variation in the phenolic acid contents of the berries was either small or moderate.

Ellagic acid and natural sources of ellagitannins as possible chemopreventive agents against intestinal tumorigenesis in the Min mouse.

Ellagic acid has been shown to have chemopreventive effects in various experimental cancer models. We wanted to see whether pure ellagic acid and natural ellagitannins from cloudberry (Rubus chamaemorus) seed and pulp have any effect on adenoma formation in Apc-mutated Min mice. From the age of 5 wk, the mice were fed either a control diet, a diet containing pure ellagic acid at 1,564 mg/kg, or diets containing 4.7% (wt/wt) cloudberry seeds or 5.3% cloudberry pulp. The concentrations of ellagitannins and free ellagic acid in the seed diet were 807 and 42 mg/kg and in the pulp diet 820 and 34 mg/kg, respectively. After the 10-wk feeding period, ellagic acid had no effect on the number or size of adenomas in the distal or total small intestine, but it increased adenoma size in the duodenum when compared with the control diet (1.50+/-0.29 vs. 1.16+/-0.31 mm; P=0.029). Neither cloudberry seed nor pulp diets had any effect on the adenoma formation. Chemopreventive effects and mechanisms of whole cloudberry and other similar sources of phenolic compounds should, however, be studied, further taking into account food matrix and interactions with other dietary constituents that may be involved in the bioavailability and metabolism of ellagitannins.

Effects of dietary anthocyanins on tocopherols and lipids in rats.

The effects of dietary cyanidin-3-O-glucoside (C3G) and concentrates from blackcurrant [Ribes nigrum] (BC) and elderberry [Sambucus nigra] (EC) on plasma and tissue concentrations of alpha- (alpha-T) and gamma-tocopherol (gamma-T) and cholesterol, as well as the fatty acid composition of the liver lipids were investigated in growing, male rats of the Sprague-Dawley strain. Animals were fed semisynthetic diets supplemented with 2 g/kg C3G, BC, or EC for 4 weeks. Dietary anthocyanins did not affect feed intake, body weight, and organ weights. C3G elevated the concentrations of tocopherols in the liver and lungs (P < 0.05). Cholesterol levels in plasma and liver were not affected by any of the regimens. C3G and BC reduced the relative amount of saturated fatty acids in the liver (P < 0.05). BC also lowered the percentage of 22:6 + 24:0 and EC the ratio of 20:3/20:4 n-6 (P < 0.05). In conclusion, dietary C3G, BC, and EC appear to have little effect on cholesterol levels and the fatty acid pattern in the liver but seem to be capable of sparing vitamin E in healthy, growing rats.