Showing papers in "Journal of Nutrition in 1995"
TL;DR: By combining the rationale of pro- and prebiotics, the concept of synbiotics is proposed to characterize some colonic foods with interesting nutritional properties that make these compounds candidates for classification as health-enhancing functional food ingredients.
Abstract: Because the human gut microbiota can play a major role in host health, there is currently some interest in the manipulation of the composition of the gut flora towards a potentially more remedial community. Attempts have been made to increase bacterial groups such as Bifidobacterium and Lactobacillus that are perceived as exerting health-promoting properties. Probiotics, defined as microbial food supplements that beneficially affect the host by improving its intestinal microbial balance, have been used to change the composition of colonic microbiota. However, such changes may be transient, and the implantation of exogenous bacteria therefore becomes limited. In contrast, prebiotics are nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacterial species already resident in the colon, and thus attempt to improve host health. Intake of prebiotics can significantly modulate the colonic microbiota by increasing the number of specific bacteria and thus changing the composition of the microbiota. Nondigestible oligosaccharides in general, and fructooligosaccharides in particular, are prebiotics. They have been shown to stimulate the growth of endogenous bifidobacteria, which, after a short feeding period, become predominant in human feces. Moreover, these prebiotics modulate lipid metabolism, most likely via fermentation products. By combining the rationale of pro- and prebiotics, the concept of synbiotics is proposed to characterize some colonic foods with interesting nutritional properties that make these compounds candidates for classification as health-enhancing functional food ingredients.
7,232 citations
TL;DR: Results are reviewed that suggest that the diphenolic isoflavonoids and lignans are natural cancer-protective compounds.
Abstract: Because many Western diseases are hormone-dependent cancers, we have postulated that the Western diet, compared with a vegetarian or semi-vegetarian diet, may alter hormone production, metabolism or action at the cellular level. Recently, our interest has been focused on the cancer-protective role of some hormone-like diphenolic phytoestrogens of dietary origin, the lignans and isoflavonoids. The precursors of the biologically active compounds originate in soybean products (mainly isoflavonoids but also lignans), as well as whole grain cereals, seeds, probably berries and nuts (mainly lignans). The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormone-like compounds with weak estrogenic and antioxidative activity; they have now been shown to influence not only sex hormone metabolism and biological activity but also intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation and angiogenesis, making them strong candidates for a role as natural cancer protective compounds. Epidemiological investigations support this hypothesis, because the highest levels of these compounds are found in countries or regions with low cancer incidence. This report is a review of results that suggest that the diphenolic isoflavonoids and lignans are natural cancer-protective compounds.
576 citations
TL;DR: The data suggest that human isoflavone bioavailability depends upon the relative ability of gut microflora to degrade these compounds, and that intestinal half-life of daidzein and genistein may be as little as 7.5 and 3.3 h, respectively.
Abstract: Soybean isoflavones have been proposed to be anticarcinogenic, but their effective doses have not been established. To study their bioavailability, seven women consumed 3.4, 6.9, or 10.3 mumol isoflavones/kg body wt in soymilk in each of three meals of a liquid diet on one of three feeding days that were separated by 2-wk washout periods. Subjects were randomly assigned to doses in a cross-over design. Plasma, urine and fecal isoflavones were measured by reverse phase HPLC. In two subjects, fecal isoflavone recovery was 10-20 times that in the other five subjects. Average 48-h urinary recoveries of ingested daidzein and genistein were 16 +/- 4 and 10 +/- 4%, respectively, at all three doses among the five subjects excreting only small amounts of isoflavones in feces, whereas urinary recoveries of daidzein and genistein in the two subjects who excreted large amounts of fecal isoflavones were 32 +/- 5 and 37 +/- 6%, respectively. Urinary isoflavone excretion was nearly zero in all subjects at 48 h after dosing. Average plasma concentration of genistein at 24 h after the breakfast isoflavone dose in subjects excreting large amounts of fecal isoflavones was significantly greater by 2.5-fold than in subjects who excreted small amounts of fecal isoflavones (P < 0.05). In vitro anaerobic incubation of isoflavones with human feces showed that intestinal half-life of daidzein and genistein may be as little as 7.5 and 3.3 h, respectively. These data suggest that human isoflavone bioavailability depends upon the relative ability of gut microflora to degrade these compounds.
532 citations
TL;DR: In mice, when given in vivo, the sterol prevents the induction of spontaneous and induced autoimmune diseases and inhibits Th1 induce IgG2a responses, suggesting that it may have potential therapeutic applications in Th1-mediated clinical situations such as autoimmunity and transplantation.
Abstract: 1,25-Dihydroxyvitamin D3 [1,25-(OH)2-D3] is known to be an immunosuppressive hormone. This review primarily deals with in vitro and in vivo effects of 1,25-(OH)2-D3 and analogue, 1,25-dihydroxy-16ene-vitamin D3 [1,25-(OH)2-16ene-D3], on T helper subsets type 1 (Th1) or type 2 (Th2) that have distinctive functional characteristics in humans. Th1 secrete interferon (IFN-gamma), interleukin (IL-2) and induce B cells to produce immunoglobulin IgG2a while Th2 secrete IL-4, IL-10 and induce the production of IgG1 and IgE by B cells. The sterol inhibits the secretion of IL-12, a cytokine produced by monocytes and B cells, which leads to the activation and differentiation of Th1. In addition, 1,25-(OH)2-D3 directly inhibits IFN-gamma secretion by Th1 clones while it has little effect on IL-4 secretion by Th2 clones. The analogue, 1,25-(OH)2-16ene-D3, is 100-fold more potent than 1,25-(OH)2-D3 in inhibiting IFN-gamma secretion but also has little effect on IL-4 secretion. In mice, when given in vivo, the sterol prevents the induction of spontaneous and induced autoimmune diseases and inhibits Th1 induce IgG2a responses. These actions of the vitamin D3 compounds suggest that it may have potential therapeutic applications in Th1-mediated clinical situations such as autoimmunity and transplantation.
489 citations
TL;DR: A large body of literature indicates that protein from soybeans reduces blood cholesterol concentrations in experimental animals as well as in humans, and one hypothesis suggests amino acid composition or proportionality of soy causes changes in cholesterol metabolism (possibly via the endocrine system).
Abstract: A large body of literature indicates that protein from soybeans reduces blood cholesterol concentrations in experimental animals as well as in humans. The mechanism and component of soy responsible has not been established fully. Some suggest that when soy protein is fed, cholesterol absorption and/or bile acid reabsorption is impaired. This is observed in some animal species, such as rabbits and rats, but not in humans nor when amino acids replace intact soy protein. Others propose that changes in endocrine status, such as alteration in insulin:glucagon ratio and thyroid hormone concentrations, are responsible. The metabolic changes that have been observed on soy protein feeding in a variety of animal models, and in some cases humans, include increased cholesterol synthesis, increased bile acid synthesis (or fecal bile acid excretion), increased apolipoprotein B or E receptor activity and decreased hepatic lipoprotein secretion and cholesterol content, which are associated with an increased clearance of cholesterol from the blood. One hypothesis suggests amino acid composition or proportionality of soy causes changes in cholesterol metabolism (possibly via the endocrine system). Others have proposed that nonprotein components (such as saponins, fiber, phytic acid, minerals and the isoflavones) associated with soy protein affect cholesterol metabolism either directly or indirectly.
403 citations
TL;DR: School-age children who suffered from early childhood malnutrition have generally been found to have poorer IQ levels, cognitive function, school achievement and greater behavioral problems than matched controls and, to a lesser extent, siblings.
Abstract: This is a review of studies on the relationship between mental development and severe malnutrition. School-age children who suffered from early childhood malnutrition have generally been found to have poorer IQ levels, cognitive function, school achievement and greater behavioral problems than matched controls and, to a lesser extent, siblings. The disadvantages last at least until adolescence. There is no consistent evidence of a specific cognitive deficit. The evidence of a causal relationship is strong but not unequivocal because of difficulties in interpreting retrospective case control studies. Marked improvements in development can occur after adoption or intervention. Therefore, the outcome depends to a large extent on the quality of the subsequent environment. It is likely that extremely deprived environments would exacerbate the effects. There is limited evidence that other nutritional deficiencies may interact with previous malnutrition in affecting cognition. The mechanism linking malnutrition to poor development is still not established.
402 citations
TL;DR: The validity of the Radimer/Cornell measures is supported and their ability to differentiate among groups of households experiencing increasingly severe food insecurity and hunger is illustrated.
Abstract: Hunger and food insecurity have been identified as core indicators of an individual's nutritional state that should be assessed in nutrition surveillance activities. Such an assessment requires a valid measure of these phenomena. This paper describes further work on the construction of measures of hunger and food insecurity based on the Radimer/Cornell items and provides an assessment of their validity. A random sample survey of 193 households with women and children living at home was conducted in 1993 in a rural county in New York State. A questionnaire containing the Radimer/Cornell hunger and food insecurity items, information about demographic characteristics, frequency of fruit and vegetable consumption, and household food supplies was administered to subjects. Measures were constructed that identified households experiencing household- and individual-level food insecurity and households with hungry children. The construct and criterion-related validity of the measures was assessed. In relation to criterion-related validity, as food insecurity worsened, there was a significant and progressive increase in the percentage of subjects participating in food programs and having low income, education and employment and a significant decline in average household food availability and fruit and vegetable consumption. These results support the validity of the Radimer/Cornell measures and illustrate their ability to differentiate among groups of households experiencing increasingly severe food insecurity and hunger.
381 citations
TL;DR: Genistein delayed mammary tumor appearance in association with increased cell differentiation in mammary tissue in rats treated with 7, 12-dimethylbenz[a]anthracene when administered neonatally, inhibited phorbol ester-induced H2O2 production in a model of skin cancer, and inhibited aberrant crypt formation in a models of colonic cancer.
Abstract: In two-thirds of studies on the effect of genistein-containing soy materials in animal models of cancer, the risk of cancer (incidence, latency or tumor number) was significantly reduced. In addition, purified genistein delayed mammary tumor appearance in association with increased cell differentiation in mammary tissue in rats treated with 7, 12-dimethylbenz[a]anthracene when administered neonatally, inhibited phorbol ester-induced H2O2 production in a model of skin cancer, and inhibited aberrant crypt formation in a model of colonic cancer. In in vitro models, genistein inhibited the proliferation of human tumor cell lines in culture with a wide variation in IC50 values (2.6-79 mumol/L, or 1-30 micrograms/mL). In only a few cases was the IC50 below 13.2 mumol/L (5 micrograms/mL), the presumed upper limit for the serum genistein concentration in those on a high soy diet. In future studies, greater emphasis should be placed on the effect of genistein on nontransformed, normal cell lines from the tissues where cancer can occur rather than established tumor cell lines. Similarly, the effect of genistein on the progression and/or promotion of cancer may be more clearly examined using nontransformed cell lines transfected with specific oncogenes thought to be activated during oncogenesis.
368 citations
TL;DR: More recent findings indicate that the kinds of behaviors and cognitive functions impaired by malnutrition may be more related to emotional responses to stressful events than to cognitive deficits per se, the age range of vulnerability to these long-term effects of malnutrition maybe much greater than the authors had suspected and the minimal amount of malnutrition (hunger) necessary to produce theseLong-term alterations is unknown.
Abstract: Our conceptions of how malnutrition endured early in life affects brain development have evolved considerably since the mid-1960s. At that time, it was feared that malnutrition endured during certain sensitive periods in early development would produce irreversible brain damage possibly resulting in mental retardation and an impairment in brain function. We now know that most of the alterations in the growth of various brain structures eventually recover (to some extent), although permanent alterations in the hippocampus and cerebellum remain. However, recent neuropharmacological research has revealed long-lasting, if not permanent, changes in brain neural receptor function resulting from an early episode of malnutrition. These more recent findings indicate that the kinds of behaviors and cognitive functions impaired by malnutrition may be more related to emotional responses to stressful events than to cognitive deficits per se, the age range of vulnerability to these long-term effects of malnutrition may be much greater than we had suspected and the minimal amount of malnutrition (hunger) necessary to produce these long-term alterations is unknown.
366 citations
352 citations
TL;DR: Soybeans are high in protein but also contain a number of minor constituents traditionally considered to be antinutritional factors such as trypsin inhibitors, phytic acid, saponins and isoflavones as mentioned in this paper.
Abstract: Soybeans are high in protein but also contain a number of minor constituents traditionally considered to be antinutritional factors. These include trypsin inhibitors, phytic acid, saponins and isoflavones. These compounds are now thought to have beneficial biological effects in the diet, such as lowering blood cholesterol or preventing cancer. Soybean processing changes the content of these minor constituents in various ways. This review discusses the changes in content of trypsin inhibitors, phytic acid, saponins and isoflavones as soybeans are processed into the conventional protein ingredients, flours, concentrates and isolates, as well as some of the traditional Oriental soybean foods.
TL;DR: Genistein may contribute to the preventive effect of plant-based diet on chronic diseases, including solid tumors, by inhibiting neovascularization and tumor cell proliferation and may have important applications in the treatment of solid tumors and angiogenic diseases.
Abstract: Consumption of a plant-based diet can prevent the development and progression of chronic diseases that are associated with extensive neovascularization. To determine whether prevention might be associated with dietary derived angiogenesis inhibitors, we have fractionated urine of healthy human subjects consuming a plant-based diet and examined the fractions for their abilities to inhibit the proliferation of vascular endothelial cells. One of the most potent fractions contained several isoflavonoids, which we identified by gas chromatography-mass spectrometry and subsequently synthesized. Of all synthetic compounds, the isoflavonoid genistein was the most potent and inhibited endothelial cell proliferation and in vitro angiogenesis at half maximal concentrations of 5 and 150 mumol/L, respectively. Moreover, genistein inhibited the proliferation of various tumor cells. Genistein excretion in urine of subjects consuming a plant-based diet is in the micromolar range, which is 30-fold higher than that of subjects consuming a traditional Western diet. The high concentrations of genistein in urine of vegetarians and our present results suggest that genistein may contribute to the preventive effect of plant-based diet on chronic diseases, including solid tumors, by inhibiting neovascularization and tumor cell proliferation. Thus genistein may have important applications in the treatment of solid tumors and angiogenic diseases.
TL;DR: The results show that dietary flavonol are recovered in rat plasma as conjugated metabolites in non-negligible concentrations, and that these flavonols may be interesting antioxidant micronutrients with a variety of biological effects.
Abstract: We studied the bioavailability and the plasma transport of flavonols in rats fed quercetin or rutin diets. Wistar rats were fed one of the following purified diets for 10 d: control; 16.4 or 8.2 mmol rutin/kg diet; or 16.4, 8.2 or 4.1 mmol quercetin/kg diet. Flavonol concentrations were determined in plasma, ileal and cecal contents, and feces. In rats fed diets containing 16.4 mmol quercetin or rutin/kg, the concentration of circulating flavonols was approximately 115 mumol/L. Quercetin or rutin administration resulted in similar concentrations of quercetin in cecal contents. By HPLC analysis and beta-glucuronidase/sulfatase treatment, plasma flavonols have been identified as conjugated quercetin itself, or a conjugated form (4.5-fold as abundant) of an aglycone less polar than quercetin. Rats fed quercetin or rutin diets had a green/yellow-colored plasma that exhibited a peak absorbance at 411 nm, vs. 363 or 375 nm for pure rutin or quercetin solutions, respectively. This shift of band I absorption was obtained when pure quercetin was in the presence of albumin or added to a plasma fraction. The bathochromic properties of flavonoids in the presence of albumin are highly dependent on the presence of the C-2/C-3 double bond on the C-ring and are influenced by the degree of B-ring hydroxylation. The existence of intermolecular bonds between albumin and quercetin is supported by in vitro absorbance and fluorescence studies. With human albumin, the fluorescence intensity and the shift of quercetin absorbance increased in parallel to the albumin/quercetin molar ratio. Conjugated diene formation, resulting from Cu(2+)-catalyzed oxidation of human LDL or rat VLDL+LDL was effectively inhibited in vitro by 0.5 mumol/L quercetin. These results show that dietary flavonols are recovered in rat plasma as conjugated metabolites in non-negligible concentrations, and that these flavonols may be interesting antioxidant micronutrients with a variety of biological effects.
TL;DR: The oxidative damage observed may have occurred as a consequence of increased reactive oxygen species generation secondary to tissue iron accumulation and/or reductions in zinc-dependent antioxidant processes.
Abstract: To investigate the effects of zinc deficiency on oxidative damage to testes proteins, lipids and DNA, weanling male rats were allowed free access to low (0.5 microgram Zn/g) or adequate (25 micrograms Zn/g) zinc diets for 14 d. A third group was restricted intake of the adequate Zn diet to the amount consumed by the low Zn diet-fed group. Compared with ad libitum-fed controls, testes from rats fed the low zinc diet had lower glutamine synthetase activity, lower Fe(2+)-stimulated 2-thiobarbituric acid-reactive substances (TBARS) production, higher protein carbonyl concentrations (P < 0.05), and higher 8-oxo-2'-deoxyguanosine levels (P = 0.06). Glutamine synthetase activity in testes of the food-restricted controls was between the values for the ad libitum controls and zinc-deficient animals. Protein carbonyls were higher in the restricted controls compared with the ad libitum controls, whereas stimulated TBARS production was lower (P < 0.05). Levels of 8-oxo-2'-deoxyguanosine were lower in testes DNA of the restricted controls than in the zinc-deficient group (P < 0.05). Testes iron concentrations were higher in the zinc-deficient and restricted control rats than in ad libitum controls (P < 0.05). The oxidative damage observed may have occurred as a consequence of increased reactive oxygen species generation secondary to tissue iron accumulation and/or reductions in zinc-dependent antioxidant processes.
TL;DR: It is demonstrated that these two selenoperoxidases are differentially regulated by dietary Se, and liver and heart GPX1 mRNA levels were reduced and PHGPX mRNA was not significantly affected by Se deficiency.
Abstract: Phospholipid hydroperoxide glutathione peroxidase (PHGPX) and classical glutathione peroxidase (GPXI) are encoded by separate genes with only about 40% amino acid and nucleic acid sequence identity. To determine the response of tissue PHGPX expression to dietary Se level and to compare these responses with those for GPXI, weanling male rats were fed amino acid diets containing from 2 (-Se) to 130 (+Se) μg Se/kg diet or a torula diet containing 5 and 190 μg Se/kg diet as Na 2 SeO 3 for 28 d. Tissues were analyzed for PHGPX and GPXI activity and mRNA. There was no effect of Se on growth. In -Se rats, GPXI activity was reduced to 1% in liver and 4-9% in heart, kidney and lung compared with +Se rats ; PHGPX activity was reduced only to 25-50% in these four tissues. The Se response curves indicated that the dietary Se requirement to reach plateau liver PHGPX activity was half that required for plateau GPX activity. In -Se rats, liver and heart GPXI mRNA levels were reduced to 6 and 12%, respectively, whereas PHGPX mRNA was not significantly affected by Se deficiency. Notably, 65 μg Se/ kg diet resulted in plateau liver GPXI mRNA levels but not plateau GPX activity. Testis had the lowest GPX activity and GPXI mRNA of all tissues examined, but had 15-fold higher PHGPX activity and 45-fold higher PHGPX mRNA levels when compared with liver. There was no significant effect of dietary Se on testis GPXI and PHGPX mRNA levels. This study demonstrates that these two selenoperoxidases are differentially regulated by dietary Se. Differences in Se regulation of mRNA levels in liver and heart were even more pronounced than for enzyme activity. The lack of any significant effect of reduced dietary Se on PHGPX mRNA levels suggests that there are detailed underlying molecular mechanisms whereby Se status regulates GPXI mRNA levels but not PHGPX mRNA levels.
TL;DR: The objectives of this study were to determine whether intestinal viscosity caused by mixed linked barley beta-glucan depresses ileal nutrient digestibility and digestive enzyme activities and to determine the interaction of intestinal Viscosity, digestive enzymes activities and ilean nutrient digestible in different ages of poultry.
Abstract: The objectives of this study were to determine whether intestinal viscosity caused by mixed linked barley beta-glucan depresses ileal nutrient digestibility and digestive enzyme activities and to determine the interaction of intestinal viscosity, digestive enzyme activities and ileal nutrient digestibility in different ages of poultry. In Experiments 1 and 2, 1-d-old broiler chicks and 1-y-old cocks, respectively, were fed diets with 60% corn, low and high viscosity barley with or without beta-glucanase, for 3 wk. A 3 x 2 factorial design was used. Comparisons were made only within the same age group. In Experiment 3, 1-d-old broiler chicks were fed high viscosity barley with and without beta-glucanase to measure fecal nutrient and ileal and fecal amino acid digestibility. Broiler chicks fed barley ate less and gained less weight than those fed corn; added beta-glucanase resulted in increases in both food consumption and weight gain for the barley-fed chicks (P < 0.05). Relative pancreas weight was higher (P < 0.05) in chicks fed barley than in those fed corn, and lower with beta-glucanase (P < 0.05). Digesta from barley-fed birds had the highest viscosities, which were decreased (P < 0.05) by beta-glucanase. Amylase and lipase were lower in broiler chicks fed high viscosity barley compared with corn (P < 0.05), and beta-glucanase increased both activities and that of trypsin as well (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It is believed that supplementation of human diets with certain soybean products shown to suppress carcinogenesis in animals could markedly reduce human cancer mortality rates.
Abstract: There is much evidence suggesting that compounds present in soybeans can prevent cancer in many different organ systems. The evidence for specific soybean-derived compounds having a suppressive effect on carcinogenesis in animal model systems is limited, however. There is evidence that the following isolated soybean derived products suppress carcinogenesis in vivo: a protease inhibitor, the Bowman-Birk inhibitor, inositol hexaphosphate (phytic acid) and the sterol β-sitosterol. Other compounds that may be able to suppress carcinogenesis in animals are the soybean isoflavones. Soybean compounds reported to have other types of anticarcinogenic activity include soybean trypsin inhibitor, saponins and genistein. There is much evidence to suggest that diets containing large amounts of soybean products are associated with overall low cancer mortality rates, particularly for cancers of the colon, breast and prostate. It is believed that supplementation of human diets with certain soybean products shown to suppress carcinogenesis in animals could markedly reduce human cancer mortality rates
TL;DR: Results indicated that fructooligosaccharides significantly increased calcium and magnesium absorption and that indigestible and fermentable carbohydrate facilitates colorectal absorption ofcium and magnesium.
Abstract: We investigated the effects of fructooligosaccharides on the absorption of calcium, magnesium and water from the colon and rectum of rats fed a control diet or the control diet containing 50 g fructooligosaccharides/kg. Chromium-mordanted cellulose was used as an unabsorbable marker to calculate apparent absorption of calcium and magnesium. There was a positive correlation (r = 0.982, P < 0.001 in rats fed the control diet and r = 0.975, P < 0.001 in rats fed the fructooligosaccharides-containing diet) between the amount of chromium and the dry weight of each fecal pellet in the colon and rectum. Ratios of calcium to chromium and magnesium to chromium in fecal pellets in the colon and rectum were calibrated from the Ca:Cr and Mg:Cr ratios of cecal contents. In rats fed the fructooligosaccharides-containing diet, but not in rats fed the control diet, these ratios were correlated with the fractional length of transit along the colon and rectum, indicating linear disappearance of calcium and magnesium during the colorectal passage. Total apparent absorption of calcium and magnesium, predicted from regression equations with the Ca:Cr and Mg:Cr ratios of cecal contents, agreed well with those calculated from the Ca:Cr and Mg:Cr ratios of feces. The consumption of fructooligosaccharides did not affect net water absorption from the colon and rectum. These results indicated that fructooligosaccharides significantly increased calcium and magnesium absorption and that indigestible and fermentable carbohydrate facilitates colorectal absorption of calcium and magnesium.
TL;DR: Soy protein ingredients are used in compounded foods for their functional properties, including water and fat absorption, emulsification, aeration (whipping) and heat setting and for increasing total protein content and improving the essential amino acids profile.
Abstract: Soy protein products are mainly used as ingredients in formulated foods and seldom are seen by the public. They consist of four broad categories. (1) Most soy proteins are derived from "white flakes," made by dehulling, flaking and defatting soybeans by hexane extraction. These may then be milled into defatted flours or grits containing approximately 50-54% protein; extracted with ethanol or acidic waters to remove flavor compounds and flatulence sugars, producing soy protein concentrates containing 65-70% protein; or processed into soy protein isolates containing 90+% protein by alkali extraction of the protein, removal of fiber by centrifugation and reprecipitation and drying of the protein. (2) Full-fat products are made in enzyme-active and in toasted forms. (3) Various dried soyfoods, including soy milk and tofu, are produced. (4) Mixtures of soy proteins with cereals, dried milk or egg fractions, gelatin, stabilizers and emulsifiers are offered for specific baking, whipping, breading and batter applications. Texturized products, resembling meat chunks or bacon chips, are made by extrusion of flours and concentrates or spinning of isolates. Soy protein ingredients are used in compounded foods for their functional properties, including water and fat absorption, emulsification, aeration (whipping) and heat setting and for increasing total protein content and improving the essential amino acids profile.
TL;DR: It is concluded that sourdough baking and other fermentation processes may improve the nutritional features of starch and demonstrate that certain salts of organic acids may have metabolic effects.
Abstract: Postprandial blood glucose and insulin responses to barley bread containing organic acids or corresponding salts were evaluated in healthy human subjects. The satiety score and the rate and extent of in vitro starch digestion were also studied. Lactic acid was generated by use of a homofermentative starter culture or added to the dough. In addition, products were baked with Ca-lactate, or with Na-propionate at two different concentrations. Consumption of the product baked with a high concentration of Na-propionate significantly lowered the postprandial blood glucose and insulin responses, and significantly prolonged the duration of satiety compared with all other breads. When subjects consumed the breads baked with sourdough, lactic acid and Na-propionate, their glucose and insulin responses were reduced compared with the wholemeal bread alone. The rate of in vitro amylolysis was reduced only by ingestion of the breads containing lactic acid, suggesting that the beneficial impact of Na-propionate on metabolic responses and satiety was related to effects other than a reduced rate of starch hydrolysis. All bread products had a similar concentration of in vitro resistant starch of 1.3-2.1 g/100 g (starch basis). It is concluded that sourdough baking and other fermentation processes may improve the nutritional features of starch. The results also demonstrate that certain salts of organic acids may have metabolic effects.
TL;DR: Electron microscopy indicated that soybean and gysophilla saponin alter cell morphology and interact with the cell membrane in different ways, and soybean saponins did not increase cell membrane permeability in a dose-dependent fashion, whereas gypsophilla Saponin, a nondietary sap onin, increased permeability with increasing concentrations.
Abstract: Saponins, which are present in plants, have been suggested as possible anticarcinogens. They possess surface-active characteristics that are due to the amphiphilic nature of their chemical structure. The proposed mechanisms of anticarcinogenic properties of saponins include direct cytotoxicity, immune-modulatory effects, bile acid binding and normalization of carcinogen-induced cell proliferation. However, the anticarcinogenic effects of saponins from commonly consumed plant foods have not been studied. Soybeans are one of the most important sources of dietary saponins. They are the main protein supplier in many vegetarian diets. Our results showed that soybean saponins at the concentration of 150-600 ppm had a dose-dependent growth inhibitory effect on human carcinoma cells (HCT-15). Viability was also significantly reduced. Soybean saponins did not increase cell membrane permeability in a dose-dependent fashion, whereas gypsophilla saponin, a nondietary saponin, increased permeability with increasing concentrations. Electron microscopy indicated that soybean and gysophilla saponins alter cell morphology and interact with the cell membrane in different ways.
TL;DR: Although zinc has multiple roles in brain function, considerable brain sparing occurs in zinc deficiency, and peripheral mechanisms of altered behavior also need to be considered.
Abstract: The majority of studies of developmental zinc deficiency and behavior were conducted in laboratory animals, primarily rats and rhesus monkeys. Effects on food intake complicate interpretation of experiments using severe zinc deficiency. Severe zinc deficiency in rats during the period of rapid brain growth has similar effects to protein calorie malnourishment during this period, including altered emotionality and food motivation. When behavior is tested during a period of zinc deprivation in immature animals, lethargy (reduced activity and responsiveness) is a prominent characteristic, but learning, attention and memory are also affected. The few supplement studies available in children did not report effects on behavior. Although zinc has multiple roles in brain function, considerable brain sparing occurs in zinc deficiency, and peripheral mechanisms of altered behavior also need to be considered.
TL;DR: The impacts of nutritional supplementation on growth coincide with the ages when growth velocities, as well as growth deficits, are greatest in this population.
Abstract: Supplementary feeding programs are common in developing countries. These programs often cannot demonstrate an impact on child growth, however, possibly because they tend to reach older children. This study examines the impact of nutritional supplementation on annual growth rates in length and weight from birth to 7 y of age in 1208 rural Guatemalan children. A series of multiple linear regression models is used to control for initial body size, diarrheal disease, home diet, socioeconomic status and gender. During the first year of life, each 100 kcal/d (418 kJ) of supplement was associated with approximately 9 mm in additional length gain and 350 g in additional weight gain; the benefit decreased to approximately 5 mm in length gain and 250 g in weight gain during the 2nd y of life. Between 24 and 36 mo of age, supplement only had a significant impact on length. There was no impact of nutritional supplementation on growth between 3 and 7 y of age. Patterns were the same if supplement intakes were expressed as a percent of recommended allowances or growth was expressed as a percent of the expected rate. These impacts of nutritional supplementation on growth coincide with the ages when growth velocities, as well as growth deficits, are greatest in this population.
TL;DR: Whey and casein diets were more protective against the development of intestinal tumors than were the red meat or soybean diets, as evidenced by a reduced incidence of rats affected, and a reduced pooled area of tumors that formed.
Abstract: The impact of different dietary protein sources (whey, casein, soybean, red meat) on the incidence, burden and mass index of intestinal tumors induced by dimethylhydrazine in male Sprague-Dawley rats was assessed. A purified diet (based on AIN-76A) with a fat concentration of 20 g/100 g and other proteins substituted for casein (20 g/100 g) was used. Whey and casein diets were more protective against the development of intestinal tumors than were the red meat or soybean diets, as evidenced by a reduced incidence of rats affected (P = 0.15), fewer tumors per treatment group (burden, P < 0.005), and a reduced pooled area of tumors (tumor mass index) that formed (P = 0.39). Intracellular concentration of glutathione, an antioxidant and anticarcinogenic tripeptide, measured in liver, was greatest in whey protein- and casein-fed rats and lowest in soybean-fed animals (P < 0.001). For other tissues (spleen, colon, tumor) the differences were not significant, although the whey-fed animals had the highest concentrations of glutathione (P = 0.8). Whey is a source of precursors (cysteine-rich proteins) for glutathione synthesis and may be important in providing protection to the host by stimulating glutathione synthesis. A positive correlation was observed between mean fecal fat concentrations for rats in each treatment group and large intestinal tumor burden (r2 = 0.898, P = 0.05). Fecal fat could be involved in aiding initiation and/or promotion of carcinogenesis. Whatever the mechanism(s), dairy proteins, and whey proteins in particular, offer considerable protection to the host against dimethylhydrazine-induced tumors relative to the other protein sources examined.
TL;DR: The differing effects of dietary proteins on serum cholesterol concentrations in humans and in rabbits are primarily due to changes in LDL cholesterol, and the hypercholesterolemia produced by dietary casein is associated with down-regulation of hepatic LDL receptors.
Abstract: Animal proteins such as casein are more hypercholesterolemic than soy protein or other plant proteins when fed to rabbits in low-fat, cholesterol-free, semipurified diets. A casein-amino acid mixture produces a hypercholesterolemia similar to that of casein. This appears to be mainly due to lysine and methionine, although other essential amino acids probably contribute to the effect. Arginine appeared to counteract the hypercholesterolemic effects of other essential amino acids. Soy protein gave a lower level of serum cholesterol in rabbits than did a soy protein-amino acid mixture, suggesting the presence of factors in soy protein that counteract the effects of hypercholesterolemic amino acids. Soy protein is also less hypercholesterolemic than casein in other animal species, particularly when the diet contains cholesterol, and substitution of soy protein for animal protein in the diet reduces the concentration of serum cholesterol in humans. This effect is somewhat variable but is generally greater in hypercholesterolemic than in normocholesterolemic subjects. The differing effects of dietary proteins on serum cholesterol concentrations in humans and in rabbits are primarily due to changes in LDL cholesterol, and the hypercholesterolemia produced by dietary casein is associated with down-regulation of hepatic LDL receptors.
TL;DR: Results indicate that under these dietary conditions, the addition of oligosaccharides to the diet induced a 20 to 30% decrease in blood urea and renal and renal nitrogen excretion relative to the control, indicating a potential for oligOSaccharide diet therapy in chronic renal disease.
Abstract: The availability of fermentable carbohydrates could influence the digestive degradation and disposal of blood urea. The effects of a poorly fermented cellulosic oat fiber, a soluble fermentable fiber (gum arabic) or one of two oligosaccharides (fructooligosaccharide or xylooligosaccharide) on nitrogen excretion were compared with a wheat starch-based control diet in male Wistar rats. The fibers and oligosaccharides were added to the semipurified diets at 7.5 g/100 g in place of wheat starch. The diets contained 13 g casein/100 g. Oat fiber did not cause an enlargement of the cecum. In contrast, gum arabic and the oligosaccharides elicited a 35-60% enlargement of the cecal wall and a 2 to 2.6-fold mean increase in the cecal pool of short chain fatty acids. Compared with rats fed the oat fiber-based diet, urea flux from blood to cecum was nearly 50% greater and more than 120% greater in those fed the gum arabic and oligosaccharide diets, respectively. In those groups, net nitrogen retention in the cecum more than doubled (nitrogen retention was calculated as the difference between net urea nitrogen flux into the cecum and ammonia nitrogen reabsorption). As a percentage of total excreted nitrogen, fecal nitrogen was 20% in the oat fiber group and 27-29% in the gum arabic and oligosaccharide groups, compared with only 10% in fiber-free controls. Results indicate that under these dietary conditions, the addition of oligosaccharides to the diet induced a 20 to 30% decrease in blood urea and renal and renal nitrogen excretion relative to the control, indicating a potential for oligosaccharide diet therapy in chronic renal disease.
TL;DR: Genistein acts as a weak estrogen, modifies cellular differentiation programs, inhibits angiogenesis, modulates cell cycle events and may precipitate apoptosis, but few of the above mechanisms in tumor cells are sensitive to the physiological serum concentrations of genistein.
Abstract: Although data from epidemiological studies and cancer models suggest that genistein plays an important role in cancer prevention, the biochemical target(s) of genistein action is (are) not known. Genistein is a potent in vitro inhibitor of protein tyrosine kinase (PTK) activity, especially that of the epidermal growth factor receptor (EGF-R), having little effect on serine/threonine kinases. This led to the suggestion that genistein might exert its anti-cancer effects through inhibiting the activity of EGF-R PTK, or other crucial PTK's, in vivo. Subsequent studies on intact tumor cell lines demonstrated that EGF-R and other growth factor receptors are able to transmit mitogenic signals in the presence of genistein. In fact, it is difficult to detect decreases in the tyrosine phosphorylation of discrete proteins after genistein treatment. Other mechanisms for the effect of genistein have been suggested from in vitro and cell culture data. Genistein not only inhibits the activity of purified topoisomerase II in vitro, but also leads to the accumulation of protein-associated single strand breaks in whole cells. Genistein also inhibits the production of reactive oxygen species which may lead to tissue damage and DNA modification. Additionally, genistein acts as a weak estrogen, modifies cellular differentiation programs, inhibits angiogenesis, modulates cell cycle events and may precipitate apoptosis. However, few of the above mechanisms in tumor cells are sensitive to the physiological serum concentrations of genistein (<18.5 μmol/L, or <5 μg/mL). Primary, nontransformed human mammary epithelial cells, which have a much greater sensitivity to genistein, would be a better system for the study of these mechanisms
TL;DR: It is concluded that a single 120-mg dose of beta- carotene increases plasma and skin beta-carotene concentrations and has no effect on plasma andSkin lycopene concentrations, suggesting a role of Lycopene in mitigating oxidative damage in tissues.
Abstract: This placebo-controlled study examined in healthy women the effects of ingestion of a single large dose of beta-carotene (120 mg) on the concentrations of beta-carotene and lycopene in plasma and skin, and the effects of UV light exposure on the concentrations of beta-carotene and lycopene in the skin. Ingestion of beta-carotene increased plasma beta-carotene concentration by 127%, from 0.26 +/- 0.06 (mean +/- SEM) to 0.59 +/- 0.07 mumol/L after 1 d, and the level remained elevated at 0.54 +/- 0.11 mumol/L after 5 d. beta-Carotene in skin, analyzed after 6 d, increased by 23%, from 1.41 +/- 0.74 to 1.74 +/- 0.72 nmol/g. beta-Carotene ingestion had no effect on the lycopene concentrations of plasma (0.37 +/- 0.11 mumol/L) or skin (1.60 +/- 0.62 nmol/g). A single exposure of a small area of one volar forearm to a dose of solar-simulated light (three times the individually determined minimal erythema dose) resulted in 31 to 46% reductions in skin lycopene concentration compared with an adjacent non-exposed area. The same UV dose did not result in significant changes in skin beta-carotene concentration. We conclude that a single 120-mg dose of beta-carotene increases plasma and skin beta-carotene concentrations and has no effect on plasma and skin lycopene concentrations. The amounts of lycopene in plasma and skin are comparable to or even greater than those of beta-carotene. When skin is subjected to UV light stress, more skin lycopene is destroyed compared with beta-carotene, suggesting a role of lycopene in mitigating oxidative damage in tissues.
TL;DR: The effect of a commercial glycanase product on the performance of 4-wk-old broiler chickens fed wheats with low and normal apparent metabolizable energy values was studied and the enzyme product significantly increased the solubilization of non-starch polysaccharides within the gastrointestinal tract of birds fed both types of wheat diets.
Abstract: The effect of a commercial glycanase product (Avizyme TX) on the performance of 4-wk-old broiler chickens fed wheats with low and normal apparent metabolizable energy values was studied. Controls were fed a corn-based diet. Supplementation with the enzyme product significantly (P<0.01) increased the apparent metabolizable energy of the low metabolizable energy wheat from 12.02 to 14.94 MJ/kg dry matter. The apparent metabolizable energy value of the normal wheat was increased from 14.52 to 14.83 MJ/kg dry matter; this was, however, not significant. Birds fed the low metabolizable energy wheat diet had significantly (P<0.01) higher digesta viscosity and lower small intestinal starch and protein digestibilities than birds fed the normal wheat diet. Chickens fed the low metabolizable energy wheat tended to grow less than those fed the normal wheat diet. When the low metabolizable energy wheat+enzyme diet was fed, digesta viscosity was significantly (P<0.01) lower (20.28 vs. 10.36 mPa.s), and small intestinal digestibility coefficient of starch was significantly (P<0.01) greater (0.584 vs. 0.861) relative to values in birds fed the low metabolizable energy wheat diet alone. Although the protein digestibility coefficient also increased from 0.689 to 0.745, the difference was not significant. Weight gain and feed efficiency of birds fed the low metabolizable energy wheat+enzyme equaled those of controls. The enzyme product significantly (P<0.01) increased the solubilization of non-starch polysaccharides within the gastrointestinal tract of birds fed both types of wheat diets. This experiment demonstrated that non-starch polysaccharide-degrading enzymes markedly increase the nutritive value of low metabolizable energy wheat broiler chicken diets, suggesting that increased level of viscous non-starch polysaccharides may cause the low apparent metabolizable energy contents of some wheats
TL;DR: The nutritional regulation of the growth hormone liver axis has been studied in gilthead sea bream and an opposite response was observed in hepatic growth hormone-binding sites and plasma insulin-like growth factor-I immunoreactivity that would reflect the insensitivity of liver to growth hormone action during relatively low protein intake.
Abstract: The nutritional regulation of the growth hormone liver axis has been studied in gilthead sea bream (Sparus aurata). In a first study, fingerling fish were fed three experimental diets with varying proportions of protein (34, 45 and 55%). A 60% decrease in plasma growth hormone concentration was observed with the increase of specific growth rates and dietary protein levels. An opposite response was observed in hepatic growth hormone-binding sites and plasma insulin-like growth factor-I immunoreactivity that would reflect the insensitivity of liver to growth hormone action during relatively low protein intake. In a second study, fish were fed a commercial diet (55% protein) at different feeding levels (0, 1.2, 2.7 and 5.5 g/(100 g body wt.d). An 84% decrease in plasma growth hormone concentration was observed with the increase of specific growth rates and feeding levels from 0 to 2.7 g/(100 g body wt.d). However, significantly greater growth hormone concentration was found in fish fed 5.5 g/(100 g body wt.d) when compared with fish fed 2.7 g/(100 g body wt.d). Hepatic growth hormone-binding sites and plasma insulin-like growth factor-I immunoreactivity increased with the increase of feeding levels from 0 to 2.7 g/(100 g body wt.d), but these values were lower in fish-fed 5.5 g/(100 g body wt.d) than in those fed 2.7 g/(100 g body wt.d). The physiological importance of these results remains to be clarified, though probably it is a part of the mechanism that diminishes feed utilization for growth at high feeding levels.(ABSTRACT TRUNCATED AT 250 WORDS)