In vivo and in vitro effects of tea extracts on enterotoxigenic Escherichia coli-induced intestinal fluid loss in animal models.

Objectives: Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of dehydrating diarrhoea in infants and early-weaned piglets living under subhygienic conditions. We studied the effect of different tea types and subfractions on the intestinal fluid and electrolyte losses involved in ETEC diarrhoea.

Materials And Methods: Jejunal segments of anaesthetised piglets were infected with ETEC or ETEC heat-labile toxin (LT) and subsequently perfused for 8 hours with control or tea solutions containing green or black tea extract (BTE) or 3 different BTE subfractions containing small-size, large-size or no phenolics.

Nuclear magnetic resonance spectroscopic based studies of the metabolism of black tea polyphenols in humans.

Epidemiological studies indicate that a high intake of flavonoids is associated with an improved health status. Tea is one of the most abundant sources of flavonoids in the human diet. The bioavailability and biotransformation of tea flavonoids are, however, not clearly understood.

Consumption of both black tea and green tea results in an increase in the excretion of hippuric acid into urine.

Background: A major portion of the catechins in green tea is not absorbed in the small intestine. Bacteria in the colon convert nonabsorbed catechins into simpler phenolic compounds, which may also be absorbed. During the production of black tea, most catechins are polymerized to complex molecules called thearubigins.

Chlorogenic acid, quercetin-3-rutinoside and black tea phenols are extensively metabolized in humans.

Dietary phenols are antioxidants, and their consumption might contribute to the prevention of cardiovascular disease. Coffee and tea are major dietary sources of phenols. Dietary phenols are metabolized extensively in the body.

Plasma concentrations of individual tea catechins after a single oral dose in humans.

1. Ten healthy volunteers ingested 1.5 mmole epicatechin gallate (ECg), epigallocatechin (EGC) or epigallocatechin gallate (EGCg) in a randomized crossover design.

Analysis of theaflavins in biological fluids using liquid chromatography-electrospray mass spectrometry.

A HPLC-MS procedure for the sensitive and specific analysis of the black tea flavonoid theaflavin in human plasma and urine was developed. Levels were measured after enzymatic deconjugation, extraction into ethyl acetate, and separation by HPLC, using tandem mass spectrometry as a detecting system. Two healthy volunteers consumed 700 mg theaflavins, equivalent to about 30 cups of black tea.

Association between trans fatty acid intake and cardiovascular risk factors in Europe: the TRANSFAIR study.

Background: High intakes of trans fatty acids (TFA) have been found to exert an undesirable effect on serum lipid profiles, and thus may increase the risk for cardiovascular disease.

Objectives: Investigation of the association between TFA intake and serum lipids.

Design: Cross-sectional study in eight European countries (Finland, France, Greece, Iceland, The Netherlands, Portugal, Spain, Sweden) among 327 men and 299 women (50-65 y).

Effects of conjugated linoleic acid (CLA) isomers on lipid levels and peroxisome proliferation in the hamster.

Effects of the conjugated linoleic acid (CLA) isomers cis-9, trans-11 (c9,t11 CLA) and trans-10, cis-12 (t10,c12 CLA) on lipid metabolism and markers of peroxisome proliferation were investigated in hamsters fed on purified diets containing 30% energy as fat and 0.1 g cholesterol/kg for 8 weeks. Four groups (n 32 each) received diets without CLA (control), with a mixture of equal amounts of c9,t11 and t10,c12 CLA (CLA mix), with c9,t11 CLA, and with t10,c12 CLA.

Intake of fatty acids in western Europe with emphasis on trans fatty acids: the TRANSFAIR Study.

Objective: To assess the intake of trans fatty acids (TFA) and other fatty acids in 14 Western European countries.

Design And Subjects: A maximum of 100 foods per country were sampled and centrally analysed. Each country calculated the intake of individual trans and other fatty acids, clusters of fatty acids and total fat in adults and/or the total population using the best available national food consumption data set.

Limited effect of consumption of uncooked (RS2) or retrograded (RS3) resistant starch on putative risk factors for colon cancer in healthy men.

To investigate whether resistant starch (RS) affects putative risk factors for colon cancer, 24 healthy men consumed a daily RS supplement for 4 wk in addition to their habitual diet in a single-blind, randomized, balanced multiple crossover trial. During the first week, all subjects consumed the control supplement containing glucose. Subsequently, each subject consumed, in random order, a supplement with RS2 (uncooked high-amylose cornstarch), RS3 (extruded and retrograded high-amylose cornstarch), and glucose, each for 1 wk.

The effect of ingestion of inulin on blood lipids and gastrointestinal symptoms in healthy females.

The effect of a daily intake of 14 g inulin added to a low-fat spread on fasting blood lipids and gastrointestinal symptoms was investigated in sixty-four young healthy women in a randomized double-blind crossover study involving two periods of 4 weeks. The test spread with and without inulin replaced habitual spread during the test periods. No significant differences between the test periods in plasma total cholesterol, HDL-cholesterol, LDL-cholesterol and triacylglycerol concentrations were observed.

Neither raw nor retrograded resistant starch lowers fasting serum cholesterol concentrations in healthy normolipidemic subjects.

The question addressed was whether dietary resistant starch would lower serum cholesterol and triacylglycerol concentrations in healthy normolipidemic subjects. In a randomized single-blind 3 x 3 Latin-square study with corrections for any carryover effects, 27 males and 30 females consumed supplements containing glucose or resistant starch (RS) from raw high-amylose cornstarch (RS2) or from retrograded high-amylose cornstarch (RS3). The RS2 and RS3 supplements provided 30 g RS/d.

Influence of dietary retrograded starch on the metabolism of neutral steroids and bile acids in rats.

Diets enriched in retrograded amylose (RS3) have been shown to lower serum cholesterol concentrations in rats. The possibility was tested that this hypocholesterolaemic effect of RS3 is caused by an increase in excretion of neutral steroids and/or bile acids. Six groups of ten rats were fed on purified diets containing either 12 or 140 g RS3/kg solid ingredients with and without added cholesterol (5g/kg).

Technique for creating a permanent cecal fistula in the rat.

A method was developed to surgically implant a silicone/stainless steel fistula-cannula in the cecum of freely moving rats. The specially designed fistula-cannula allows sampling of cecal contents at any time without disturbing the physiologic functions of the intestinal tract, as evaluated by observation of general well-being and postmortem macroscopic inspection. The fistula-cannula was implanted in 12 male rats under general anesthesia.

Interaction between physical structure and amylose:amylopectin ratio of foods on postprandial glucose and insulin responses in healthy subjects.

Objective: To study the effect of amylose content on postprandial glucose and insulin responses in healthy subjects by serving fixed amounts of simple starchy foods with a varying but strictly controlled water, fat and guar gum content.

Design: A blind, randomised, balanced cross-over study.

Setting: The kitchen of the Nutrition Research Unit in the Unilever Research Laboratorium.

Replacement of digestible by resistant starch lowers diet-induced thermogenesis in healthy men.

The present study describes the effect of replacement of digestible starch by resistant starch (RS) on diet-induced thermogenesis (DIT), postprandial glucose and insulin responses, and colonic fermentation. Ten healthy males consumed three test meals, consisting of diluted, artificially-sweetened fruit syrup and either 50 g raw potato starch (550 g RS/kg), or 50 g pregelatinized potato starch (0 g RS/kg) or 30 g pregelatinized potato starch plus 20 g lactulose (670 g indigestible disaccharide/kg). The meals were served in the morning after an overnight fast.

Both raw and retrograded starch decrease serum triacylglycerol concentration and fat accretion in the rat.

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch (prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, weight of the epididymal fat pads, serum total cholesterol and triacylglycerol concentrations and a number of intestinal and faecal variables were determined.

Effect of resistant starch on breath-hydrogen and methane excretion in healthy volunteers.

Colonic fermentation of dietary carbohydrates and fiber might produce a protective effect against the development of large bowel cancer. Resistant starch, ie, starch that escapes small bowel digestion, is a candidate fermentable substrate that has been hitherto little studied. We supplemented 19 healthy volunteers with 15 g native amylomaize (Hylon-VII) three times a day, containing 28 g type II resistant starch, or with dextrins as a placebo for 7 d in a crossover design.

Resistant starch decreases serum total cholesterol and triacylglycerol concentrations in rats.

Rats were meal-fed semipurified diets containing a low (0.8 g/MJ) and a high (9.6 g/MJ) amount of resistant starch (RS) or various amounts of RS (0.

Dietary native resistant starch but not retrograded resistant starch raises magnesium and calcium absorption in rats.

The effects on calcium and magnesium absorption of dietary native and retrograded cornstarch were studied in rats. Uncooked high amylose starch granules (35% of total glucose equivalents as enzyme-resistant starch) and cooked and cooled (-20 degrees C) high amylose starch (24% of total glucose equivalents as retrograded resistant starch) were used as test starches, and cooked normal starch (3% of total glucose equivalents as resistant starch) was used as control starch. Native vs.

Effects of the amylose content of breakfast and lunch on postprandial variables in male volunteers.

The impact of the amylose content of breakfast and lunch on postprandial variables was investigated in 22 normal-weight healthy males. Areas under the curve for insulin but not glucose were significantly smaller after the high-amylose breakfasts. Areas under the curve for both glucose and insulin were significantly smaller after the high-amylose lunches.

Amylose-amylopectin ratio in a meal affects postprandial variables in male volunteers.

To study the postprandial effects of changing the amylose-to-amylopectin ratio (Am:Ap) in the starch fraction of a meal, male volunteers were given hot mixed lunches (13% of energy as protein, 24% as fat, 6% as mono- and disaccharides, and 57% as polysaccharides) in which Am:Ap was either 0:100 or 45:55. The increase in Am:Ap resulted in a change in the shape of the glucose and insulin responses in the blood with significantly lower initial responses but a small increase for glucose and a decrease for insulin if averaged over the 6 h of the study. The rises in the concentration of free glycerol and free fatty acid that occurred after an initial drop were stronger at low Am:Ap.