bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomics and proteomics: importance for the future of nutrition research
Authors: Daniel H.
Published: July 2006

A huge number of genes within the human genome code for proteins that mediate and/or control nutritional processes. Although a large body of information on the number of genes, on chromosomal localisation, gene structure and function has been gathered, we are far from understanding the orchestrated way of how they make metabolism. Nevertheless, based on the genetic information emerging on a daily basis, we are offered fantastic new tools that allow us new insights into the molecular basis of human metabolism under normal as well as pathophysiological conditions. Recent technological advancements have made it possible to analyse simultaneously large sets of mRNA and/or proteins expressed in a biological sample or to define genetic heterogeneity that may be important for the individual response of an organism to changes in its nutritional environment. Applications of the new techniques of genome and proteome analysis are central for the development of nutritional sciences in the next decade and its integration into the rapidly developing era of functional genomics.
Induced changes in the consumption of coffee alter ad libitum dietary intake and physical activity level
Authors: Mosdøl Annhild , Christensen Benedicte , Retterstøl Lars , Thelle Dag S.
Published: July 2006

Dietary trials with subjects on a freely selected diet may be affected by unwanted behavioural changes. Few studies, if any, have examined changes in coffee consumption and possible concomitant changes in diet and health-related habits. The aim of the present study was to examine whether induced changes in coffee consumption lead to changes in food habits and leisure-time physical activity. Healthy, non-smoking coffee-drinkers (n 214) were asked to change their coffee habits in a controlled clinical trial on the metabolic effects of coffee. The participants were asked to maintain their usual dietary habits. Self-perceived changes in diet and physical activity during the 6-week intervention period were assessed at the end. In the analyses, the participants were rearranged into groups reflecting the difference in coffee intake during the trial as compared with habitual intake. Associations with changes in food intake or physical activity were analysed by Spearman rank correlation. Changes in intake of ‘chocolate, sweets’ (r 0·179, P<0·05), ‘cakes, sweet biscuits, pastry’ (r 0·306, P<0·001), and ‘jam’ (r 0·198, P<0·05) showed positive associations with change in coffee intake during the trial. Negative associations were found for ‘dishes with fish’ (r -0·204, P<0·01) and many of the drinks as well as with physical activity (r -0·164, P<0·05). Induced changes in coffee intake seem to alter ad libitum intake of several foods. The recognized associations between health behaviours may have physiological explanations.
Positive effects of a chicken eggshell powder-enriched vitamin–mineral supplement on femoral neck bone mineral density in healthy late post-menopausal Dutch women
Authors: Schaafsma Anne , van Doormaal Jasper J. , Muskiet Frits A. J. , Hofstede Gert J. H. , Pakan Igor , van der Veer Eveline
Published: July 2006

Although bone metabolism is largely under genetic control, the role of nutrition is considerable. The present study evaluates the effects of chicken eggshell powder, a new source of dietary Ca, and purified CaCO3 on bone mineral density (BMD) of the lumbar spine and hip. Besides BMD we also looked at biochemical markers of bone and Ca metabolism. Both Ca sources were provided in combination with minerals and vitamins including Mg, cholecalciferol and phylloquinone. We designed a randomised, double-blind, placebo-controlled study to take place over 12 months. Healthy Caucasian women (n 85), selected by age (≥50 and <70 years), from the databases of general practitioners were recruited by telephone calls. They had to be at least 5 years post-menopausal, with lumbar spine T-score being >-2·5. At baseline, their mean habitual daily Ca intake was adequate. The women were randomly allocated to: eggshell powder-enriched (group A; n 24), purified CaCO3-enriched (group B; n 22), or a placebo product (group C; n 27). BMD was measured at baseline and then after 6 and 12 months of supplementation as were the biochemical markers bone-specific alkaline phosphatase, amino-terminal propeptide extension of type I collagen, deoxypyridinoline, calcitonin, intact parathyroid hormone, calcidiol, and urinary Ca. After 12 months of supplementation, only mean BMD of the femoral neck in group A was significantly increased (P=0·014) by 1·75 % (95 % CI 0·18, 3·32) compared with a decrease of -0·60 % (95 % CI -1·92, 0·72) in group C. This increase coincided with significant decreases in markers of bone resorption and formation. No significant changes were seen in BMD at other sites, including lumbar spine, nor in groups B and C. No differences were found between groups A and B, or B and C. The present study indicates that healthy late post-menopausal women with an adequate Ca intake at baseline may increase BMD of the hip within 12 months following supplementation with the chicken eggshell powder-enriched supplement.
Preferential incorporation oftrans,trans-conjugated linoleic acid isomers into the liver of suckling rats
Authors: Yang Lin , Venus Yeung Sai Ying , Huang Yu , Qing Wang Han , Chen Zhen-Yu
Published: July 2006

The present study was designed to compare the conjugated linoleic acid (CLA) isomeric distribution pattern in the liver of suckling rats in relation to those in the milk and maternal diet. Silver-ion HPLC was used to separate individual CLA isomers. It was found that the isomeric distribution pattern in the milk was very similar to that in the maternal dietary fat. However, the CLA isomeric distribution patterns in the liver phospholipids (PL) and triacylglycerols were different from those in the diet and milk. In the liver PL, totalcis/transisomers accounted for 63·6–63·9 % of total CLA, which was in contrast to the values of 88·1–89·1 % in the milk and diet. In the liver PL, totaltrans/transisomers were 20·6–20·8 % of the total CLA isomers whereas they were only 2·6–3·7 % in the milk and diet. It is concluded thattrans/trans-CLA were preferentially incorporated into the liver whereas for the incorporation ofcis/trans-CLA there was partial discrimination.
Procyanidins are not bioavailable in rats fed a single meal containing a grapeseed extract or the procyanidin dimer B3
Authors: Donovan Jennifer L. , Lee Adam , Manach Claudine , Rios Laurent , Morand Christine , Scalbert Augustin , Rémésy Christian
Published: July 2006

Flavanols are the most abundant flavonoids in the human diet where they exist as monomers, oligomers and polymers. In the present study, catechin, the procyanidin dimer B3and a grapeseed extract containing catechin, epicatechin and a mixture of procyanidins were fed to rats in a single meal. After the meals, catechin and epicatechin were present in conjugated forms in both plasma and urine. In contrast, no procyanidins or conjugates were detected in the plasma or urine of any rats. Procyanidins were not cleaved into bioavailable monomers and had no significant effects on the plasma levels or urinary excretion of the monomers when supplied together in the grapeseed extract. We conclude that the nutritional effects of dietary procyanidins are unlikely to be due to procyanidins themselves or monomeric metabolites with the intact flavonoid-ring structure, as they do not exist at detectable concentrationsin vivo. Future research should focus on other procyanidin metabolites such as phenolic acids and on the effects of the unabsorbed oligomers and polymers on the human gastrointestinal tract.
Oral ingestion of lactic-acid bacteria by rats increases lymphocyte proliferation and interferon-γ production
Authors: Aattouri Najat , Bouras Mohammed , Tome Daniel , Marcos Ascension , Lemonnier Daniel
Published: July 2006

The effect of feeding lactic-acid bacteria on indices of functions of lymphocytes obtained from Peyer's patches, peripheral blood and spleen from inbred Wistar-Furth rats were studied. Rats were fed on purified diets supplemented with 350 g milk or yoghurt/kg diet for 4 weeks. At the end of the feeding period, immune cells from the three sites were isolated and proliferation, interferon-γ production and lymphocyte subset composition were studied. Rats consuming yoghurt had a greater in vitro proliferative response to yoghurt bacteria in the three lymphoid compartments, a greater interferon-γ production in response to bacteria and concanavalin A in Peyer's patches and spleen, and a greater number of Peyer's patches B lymphocytes than milk-fed rats. Macrophage and T lymphocyte proportions and lymphocyte subset composition in the three sites were unaffected by yoghurt. These results indicate that feeding live bacteria contained in yoghurt may interact with the intestinal immune system, and influence the systemic immune system.
Validation of a short food frequency questionnaire to assess folate intake
Authors: Pufulete Maria , Emery Peter W. , Nelson Michael , Sanders Thomas A. B.
Published: July 2006

A short quantitative food frequency questionnaire (FFQ) to assess folate intake was developed and validated against a 7-d weighed food intake record (7d-WR) and biochemical indices of folate status. Thirty-six men and women completed the self-administered FFQ on two occasions a month apart, kept a 7d-WR and gave two fasting blood samples at the beginning and end of the study for measuring serum and erythrocyte folate, respectively. Mean folate intakes were similar by repeat FFQ and correlated strongly (r 0·77 and r 0·72, P<0·001, for men and women, respectively). All other comparisons were done using the results of the FFQ administered on the first occasion. Men reported similar folate intakes on the FFQ and 7d-WR, but women reported greater intakes on the FFQ compared with the 7d-WR (P<0·05). There was a statistically significant correlation (partial, controlling for gender) between folate intakes reported by FFQ and 7d-WR (r 0·53, P<0·01). Folate intakes estimated by FFQ correlated significantly with serum (r 0·47, P<0·01), but not erythrocyte folate (r 0·25, P>0·05); the strength of the association was greater in men than in women. Validity coefficients estimated using the method of triads were higher for the FFQ than for the 7d-WR when serum folate was used as the biomarker. Overall, these results suggest that this short FFQ is a useful method for assessing folate intake, particularly in men.
Dietary myristic acid modifies the HDL-cholesterol concentration and liver scavenger receptor BI expression in the hamster
Authors: Loison Carole , Mendy François , Sérougne Colette , Lutton Claude
Published: July 2006

The influence of myristic acid in a narrow physiological range (0·5 to 2·4 % of total dietary energy) on the plasma and hepatic cholesterol metabolism was investigated in the hamster. The hamsters were fed on a diet containing 12·5 g fat/100 g and 0·05 g cholesterol/100 g with 0·5 % myristic acid (LA diet) for 3 weeks (pre-period). During the following 3 weeks (test period), they were divided into four dietary groups with 0·5 % (LA), 1·2 % (LM), 1·8 % (ML) or 2·4 % (M) myristic acid. Finally, half the hamsters in each group were again fed the LA diet for another 3 weeks (post-period). At the end of the test period, the hepatic expression of the scavenger receptor BI (SR-BI) was lower in the LM, ML and M groups than in the LA group whereas the hepatic cholesteryl ester concentration was higher. Cholesterol 7α hydroxylase activity was lower in the ML and M groups than in the LA and LM groups while the sterol 27 hydroxylase and 3-hydroxy-3-methyl glutaryl coenzyme A reductase activities were not modulated by dietary myristic acid. This is the first time a negative correlation has been observed between the HDL-cholesterol concentration and the hepatic mass of SR-BI (r-0·69;P<0·0001) under physiological conditions. An inverse linear regression was also shown between SR-BI and the percentage of myristic acid in the diet (r-0·75;P<0·0001). The hepatic mass of SR-BI in the M group had increased at the end of the post-period compared with the test-period values. The present investigation shows that myristic acid modulates HDL-cholesterol via a regulation of the SR-BI expression.
Green tea extract only affects markers of oxidative status postprandially: lasting antioxidant effect of flavonoid-free diet
Authors: Young J. F. , Dragsted L. O. , Haraldsdóttir J. , Daneshvar B. , Kall M. A. , Loft S. , Nilsson L. , Nielsen S. E. , Mayer B. , Skibsted L. H. , Huynh-Ba T. , Hermetter A. , Sandström B.
Published: July 2006

Epidemiological studies suggest that foods rich in flavonoids might reduce the risk of cardiovascular disease and cancer. The objective of the present study was to investigate the effect of green tea extract (GTE) used as a food antioxidant on markers of oxidative status after dietary depletion of flavonoids and catechins. The study was designed as a 2×3 weeks blinded human cross-over intervention study (eight smokers, eight non-smokers) with GTE corresponding to a daily intake of 18·6 mg catechins/d. The GTE was incorporated into meat patties and consumed with a strictly controlled diet otherwise low in flavonoids. GTE intervention increased plasma antioxidant capacity from 1·35 to 1·56 (P<0·02) in postprandially collected plasma, most prominently in smokers. The intervention did not significantly affect markers in fasting blood samples, including plasma or haemoglobin protein oxidation, plasma oxidation lagtime, or activities of the erythrocyte superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase. Neither were fasting plasma triacylglycerol, cholesterol, α-tocopherol, retinol, β-carotene, or ascorbic acid affected by intervention. Urinary 8-oxo-deoxyguanosine excretion was also unaffected. Catechins from the extract were excreted into urine with a half-life of less than 2 h in accordance with the short-term effects on plasma antioxidant capacity. Since no long-term effects of GTE were observed, the study essentially served as a fruit and vegetables depletion study. The overall effect of the 10-week period without dietary fruits and vegetables was a decrease in oxidative damage to DNA, blood proteins, and plasma lipids, concomitantly with marked changes in antioxidative defence.
Short-term consumption of a high-sucrose diet has a pro-oxidant effect in rats
Authors: Busserolles Jérôme , Rock Edmond , Gueux Elyett , Mazur Andrzej , Grolier Pascal , Rayssiguier Yves
Published: July 2006

The underlying mechanisms for the detrimental consequences of a high-fructose diet in animal models are not clear. However, the possibility exists that fructose feeding facilitates oxidative damage. Thus, the aim of the present study was to assess, in weaning rats, the effect of a high-sucrose diet v. starch diet for 2 weeks on oxidative stress variables. Plasma lipid levels were measured and lipid peroxidation was evaluated by urine and plasma thiobarbituric acid-reactive substances (TBARS). The susceptibilities of several tissues to peroxidation were determined in tissue homogenates after in vitro lipid peroxidation. Antioxidant defence variables were evaluated by measuring plasma and heart vitamin E levels, and heart superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. Higher plasma triacylglycerol (P<0·01) and TBARS (P<0·01) levels were found in rats fed the sucrose diet as compared with the starch-fed group, whereas plasma α-tocopherol levels were significantly decreased in the sucrose-fed group compared with the starch-fed group (P<0·01). Higher urine TBARS (P<0·01) were found in the sucrose-fed group compared with the starch-fed group, suggesting increased production of these substances from lipid peroxidation in vivo. Higher susceptibility to peroxidation in heart, thymus and pancreas was also found in the sucrose-fed group v. the starch-fed group. No statistical differences were observed for liver TBARS level between the two groups. Heart SOD activity was significantly decreased (P<0·001) in the sucrose-fed group compared with the starch-fed group, whereas heart vitamin E level and GPX activity were not different between the groups. However, the in vitro generation of superoxide radical in heart homogenate, measured by electron spin resonance detection and spin trapping, was not increased in the sucrose-fed group compared with starch-fed rats. Altogether, the results indicate that a short-term consumption of a high-sucrose diet negatively affects the balance of free radical production and antioxidant defence in rats, leading to increased lipid susceptibility to peroxidation.
The bioavailability and postprandial utilisation of sweet lupin (Lupinus albus)-flour protein is similar to that of purified soyabean protein in human subjects: a study using intrinsically15N-labelled proteins
Authors: Mariotti François , Pueyo Maria E. , Tomé Daniel , Mahé Sylvain
Published: July 2006

Sweet lupin (Lupinus albus), a protein-rich legume devoid of anti-nutritional factors, is considered to have a high potential for protein nutrition in man. Results concerning the nutritional value of lupin protein are, however, conflicting in animals and very scarce in human subjects. Furthermore, where fibre-rich protein sources are concerned, the long-term nutritional results are often obscured, particularly since fibre-promoted colonic fermentation may bias the energy supply and redistribute N flux. We therefore studied, during the postprandial phase, the bioavailability and utilisation of lupin-flour protein in nine healthy men who had ingested a mixed meal containing intrinsically15N-labelled lupin flour as the protein source (Expt 1). The real ileal digestibility (RID) and ileal endogenous N losses (IENL) were assessed using a perfusion technique at the terminal ileum, and the N content and15N enrichment of ileal samples. Lupin flour exhibited a high RID of 91 (SD 3) % AND LOW IENL (5·4 (sd 1·3) mmol N/h). Postprandial dietary deamination was also assessed from body dietary urea and urinary dietary N excretion, and compared with results in nine healthy men following an isoenergetic meal containing a15N-soyabean-protein isolate with a similar RID, as a control (Expt 2). Postprandial dietary deamination was similar after lupin and soyabean meals (17 (sd 2) and 18 (sd 4) % ingested N respectively). We therefore conclude that lupin protein is highly bioavailable, even if included in fibre-rich flour, and that it can be used with the same efficiency as soyabean protein to achieve postprandial protein gain in healthy human subjects.
Nutritional advantages of probiotics and prebiotics
Authors: Marteau P. , Boutron-Ruault M. C.
Published: July 2006

The potential ‘nutritional advantages’ of probiotics and prebiotics consist of preventive, and sometimes curative, effects against certain diseases. The evidence supporting such advantages, which requires randomised controlled trials and consistency of results from study to study, is rapidly increasing. This article summarizes the effects against diseases of intestinal origin. There is a high level of evidence for positive effects of some prebiotics to alleviate constipation and treat hepatic encephalopathy. Interesting aspects, but with a lower level of evidence at the present time, include prevention of colon cancer, intestinal infection, and recurrence of inflammatory bowel disease. There is a high level of evidence for positive effects of some probiotics in the alleviation of lactose intolerance, antibiotic-associated intestinal disorders and gastroenteritis. Evidence is rapidly growing regarding the prevention of recurrence of inflammatory bowel diseases. Positive trials have suggested preventive effects against intestinal colonization with specific gut pathogens includingClostridium difficileandHelicobacter pylori.
Total body phylloquinone and its turnover in human subjects at two levels of vitamin K intake
Authors: Olson Robert E. , Chao Jean , Graham Donna , Bates Margaret W. , Lewis Jessica H.
Published: July 2006

The aims of this study were to determine the total body phylloquinone and its metabolic turnover in human subjects using a tracer dose of [5-H3]phylloquinone containing 55·5×104MBq/mmol. Seven subjects aged 22 to 49 years were given 0·3 μg isotopic phylloquinone intravenously on a control diet (75 μg phylloquinone/d) and blood, urine and faeces were sampled periodically for 6 d. Five of these subjects were studied a second time after 3–8 weeks on a low-vitamin K diet (8 μg/d). The changes in the radioactivity of plasma phylloquinone with time were analysed by the method of residuals and fitted to a curve composed of two exponential components. The size of the exchangeable body pool was calculated by isotope dilution. Plasma phylloquinone levels fell during vitamin K restriction but the vitamin K-dependent coagulation factors did not change. After injection the first exponential decay curvet1/2was 1·0 (SD 0·47) H IN THE SUBJECTS ON THE CONTROL DIET AND 0·49 (sd 0·27) h after vitamin K restriction. On the control diet, the second exponentialt1/2was 27·6 (sd 124) h that did not change on the low-vitamin K diet (t1/2=25·1 (sd 13·5) h). These results indicate that the turnover time for phylloquinone in human subjects is about 1·5 d. Urinary excretion of3H-metabolites ranged from 30 % of the administered dose on the control diet to 38 % on the restricted diet and had the same turnover rate as the second component of the plasma decay curves. The exchangeable body pool of phylloquinone declined from about 1·0 μg/kg before restriction to lower values after vitamin K restriction. The faecal excretion of phylloquinone and its metabolites fell from 32 % of the administered dose on the control diet to 13 % on the restricted diet.
Degradation of transgenic DNA from genetically modified soya and maize in human intestinal simulations
Authors: Martín-Orúe Susana M. , O'Donnell Anthony G. , Ariño Joaquin , Netherwood Trudy , Gilbert Harry J. , Mathers John C.
Published: July 2006

The inclusion of genetically modified (GM) foods in the human diet has caused considerable debate. There is concern that the transfer of plant-derived transgenes to the resident intestinal microflora could have safety implications. For these gene transfer events to occur, the nucleic acid would need to survive passage through the gastrointestinal tract. The aim of the present study was to evaluate the rate at which transgenes, contained within GM soya and maize, are degraded in gastric and small bowel simulations. The data showed that 80 % of the transgene in naked GM soya DNA was degraded in the gastric simulations, while no degradation of the transgenes contained within GM soya and maize were observed in these acidic conditions. In the small intestinal simulations, transgenes in naked soya DNA were degraded at a similar rate to the material in the soya protein. After incubation for 30 min, the transgenes remaining in soya protein and naked DNA were 52 (SEM 13·1) % AND 34 (sem 17·5) %, respectively, and at the completion of the experiment (3 h) these values were 5 % and 3 %, respectively. In contrast to the soya transgene, the maize nucleic acid was hydrolysed in the small intestinal simulations in a biphasic process in which approximately 85 % was rapidly degraded, while the rest of the DNA was cleaved at a rate similar to that in the soya material. Guar gum and tannic acid, molecules that are known to inhibit digestive enzymes, did not influence the rate of transgene degradation in soya protein. In contrast guar gum reduced the rate of transgene degradation in naked soya DNA in the initial stages, but the polysaccharide did not influence the amount of nucleic acid remaining at the end of the experiment. Tannic acid reduced the rate of DNA degradation throughout the small bowel simulations, with 21 (sem 5·4) % and 2 (sem 1·8) % of the naked soya DNA remaining in the presence and absence of the phenolic acid, respectively. These data indicate that some transgenes in GM foods may survive passage through the small intestine.
Variation between sheep in renal excretion of [14C]allantoin
Authors: Prasitkusol P. , Ørskov E. R. , Chen X. B. , Hovell F. D. DeB. , Kyle D. J.
Published: July 2006

The objectives of the present study were to investigate the recovery of [14C]allantoin in urine of sheep dosed intravenously and degradation of allantoin by rumen micro-organisms. The recovery of [14C]allantoin in the urine of eight sheep was measured during three periods in two experiments. Individual values of [14C]allantoin recovery varied from 66 to 95 % (mean value 83 (SE 1·6) %). The recovery of [14C]allantoin showed no relation to the level of feed intake. There was some evidence that glomerular filtration rate was an important factor affecting the amount of urinary allantoin recovered in one experiment. Incomplete recovery of plasma [14C]allantoin in the urine indicated losses of plasma [14C]allantoin via non-renal routes. This is supported by the disappearance of14C from rumen contents incubatedin vitrowith [14C]allantoin for 48 h (88 %) and the presence of14C in salivain vivofrom sheep sampled after dosing with [14C]allantoin. However, the amount of14C activity in the saliva was very low (equivalent to only 1·5 % of the total dose in sheep producing saliva at a rate of 15 litres/d). The proportion of renal and non-renal excretion of purine derivatives was found to be unpredictable both between and within individual animals. The factors responsible for this variability need to be identified, and existing models of excretion of purine derivatives may need to be modified accordingly to improve their accuracy of prediction. A single intravenous injection of [4,5-14C]allantoin provides a simple alternative to infusion methods used to measure the proportion of plasma allantoin excreted in the urine of sheep. Using this method it may be feasible to validate PD excretion models in other ruminant livestock.
Variation in fat, lactose and protein in human milk over 24h and throughout the first year of lactation
Authors: Mitoulas Leon R. , Kent Jacqueline C. , Cox David B. , Owens Robyn A. , Sherriff Jillian L. , Hartmann Peter E.
Published: July 2006

Fat in human milk is extremely variable and can represent up to 50 % of infant energy intake. To accurately determine milk composition and infant intake at 1 (n 17), 2 (n 17), 4 (n 17), 6 (n 15), 9 (n 6) and 12 (n 5) months of lactation, samples of fore- and hind-milk were collected from each breast at each feed over 24 h periods from an initial group of seventeen women. The content of fat in milk varied over 24 h, with a mean CV of 47·6 (SE 2·1) % (N 76) AND 46·7 (se 1·7) % (n 76) for left and right breasts respectively. The 24 h amounts of fat, lactose and protein in milk differed between women (P=0·0001), but were consistent between left and right breasts. Daily milk production differed between breasts (P=0·0001) and women (P=0·0001). Accordingly, amounts of fat (P=0·0008), lactose (P=0·0385) and protein (P=0·0173) delivered to the infant over 24 h also differed between breasts and women (P=0·0001). The energy content of milk and the amount of energy delivered to the infant over 24 h were the same between breasts, but differed between women (P=0·0001). The growth rate of a group of only six infants in the present study was not related to either the concentrations or amounts of fat, lactose, protein and energy in milk over the first 6 months of life. These results show the individuality of milk composition and suggest that only a rigorous sampling routine that takes into account all levels of variation will allow the accurate determination of infant intake of fat, lactose, protein and energy.
Dietaryn-3 andn-6 fatty acids alter avian metabolism: metabolism and abdominal fat deposition
Authors: Newman Ronald E. , Bryden Wayne L. , Fleck Eva , Ashes John R. , Buttemer William A. , Storlien Leonard H. , Downing Jeffery A.
Published: July 2006

The effects of dietary saturated fatty acids and polyunsaturated fatty acids (PUFA) of then-3 andn-6 series on weight gain, body composition and substrate oxidation were investigated in broiler chickens. At 3 weeks of age three groups of chickens (n30; ten birds per group) were fed the fat-enriched experimental diets for 5 weeks. These diets were isonitrogenous, isoenergetic and contained 208 g protein/kg and 80 g edible tallow, fish oil or sunflower oil/kg; the dietary fatty acid profiles were thus dominated by saturated fatty acids,n-3 PUFA orn-6 PUFA respectively. Resting RQ was measured in five birds from each treatment group during weeks 4 and 5 of the experiment. There were no significant differences between treatments in total feed intake or final body mass. Birds fed the PUFA diets had lower RQ and significantly reduced abdominal fat pad weights (P<0·01) compared with those fed tallow. The dietary lipid profile changes resulted in significantly greater partitioning of energy into lean tissue than into fat tissue (calculated as breast lean tissue weight:abdominal fat mass) in the PUFA groups compared with the saturated fat group (P<0·01; with no difference between then-3 andn-6 PUFA groups). In addition, the PUFA-rich diets lowered plasma concentrations of serum triacylglycerols and cholesterol. The findings indicate that dietary fatty acid profile influences nutrient partitioning in broiler chickens.
Dietaryn-3 andn-6 fatty acids alter avian metabolism: molecular-species composition of breast-muscle phospholipids
Authors: Newman Ronald E. , Bryden Wayne L. , Fleck Eva , Ashes John R. , Storlien Leonard H. , Downing Jeffery A.
Published: July 2006

The effects of diets high inn-3 polyunsaturated fatty acids (PUFA; provided by fish oil),n-6 PUFA (sunflower oil) or in more-saturated fatty acids (tallow) on the distribution of subclasses of choline phospholipids (PC) and ethanolamine phospholipids (PE) from the breast muscle of broiler chickens were examined. Supplementation with the different fatty acids had no effect on the distribution of phospholipid subclasses. Feeding sunflower oil or tallow gave a molecular-species profile similar in both fatty acid subtype and proportion. In the diacyl PC phospholipids, 16: 0–18: 1n-9 and 16: 0–18: 2n-6 accounted for approximately 60 % of the total molecular species, whereas for the alkylenyl PC the predominant species were 16: 0–18: 1n-9 and 16: 0–20: 4n-6. Of the diacyl PE the dominant species was 18: 0–20: 4n-6 which accounted for 50 % of the molecular species, and of the alkylenyl PE the dominant species were 16: 0–18: 1n-9, 16: 0–20: 4n-6 and 18: 0–20: 4n-6. Supplementation with fish oil significantly increased levels of both eicosapentaenoic acid (20: 5n-3) and docosahexaenoic acid (22: 6n-3) in PC and PE when compared with either sunflower oil or tallow supplementation. The increase in then-3 PUFA incorporation was associated with a corresponding decrease in the proportion of arachidonic acid (20: 4n-6) in both PC and PE. Different dietary fats induce different patterns of fatty acid incorporation and substitution in thesn-2 position of the diacyl and alkylenyl PC and PE of avian breast muscle, and this finding is indicative of selective acyl remodelling in these two phospholipids.
Influence of the pattern of peptide supply on microbial activity in the rumen simulating fermenter (RUSITEC)
Authors: Russi Juan P. , Wallace R. John , Newbold C. James
Published: July 2006

The source and pattern of N supply was varied in the rumen simulation technique (RUSITEC) in order to determine if continuous, rather than transient, availability of peptides was required for optimum ruminal fermentation. The energy source was fibre prepared from sugar-beet pulp. N was added as NH3continuously infused (AC) or peptides (Bacto®Casitone, a pancreatic hydrolysate of casein; Difco Laboratories, Detroit, MI, USA) continuously infused (PC) or added as a single dose at the time of feeding (PS). Free peptides were detected in the fermenter liquid for 4 h after feeding in the AC treatment, for 10 h in the PS treatment, and at all times with the PC treatment. Treatments had no effect on DM degradation. Approximately 40 % of the degradation occurred during the time no peptides were detected in the PS treatment. Microbial N flow tended to be higher with the peptide additions (P<0·061), with no significant difference between the two peptides treatments. The production of liquid-associated micro-organisms (LAM) was higher in the PC treatment (P<0·05) and the proportion of LAM derived from NH3lower (P<0·05). However, LAM only accounted for 20–30 % total microbial population. Our main conclusion was that peptides had a small stimulatory effect on the fermentation, but there was no indication that synchrony of supply of energy and amino acid-N in the fermenter promoted a more efficient fermentation than non-synchronous supply. This conclusion must be qualified, however, because some N remained in the fibre and may have become available progressively as the fibre was digested by the micro-organisms.
Divalent metal inhibition of non-haem iron uptake across the rat duodenal brush border membrane
Authors: Smith Michael W. , Shenoy K. Bhasker , Debnam Edward S. , Dashwood Michael R. , Churchill Linda J. , Srai S. Kaila
Published: July 2006

Duodenal Fe2+ uptake is essential to body Fe2+ homeostasis, but the interaction of metals with the uptake process remains unclear. The present study compared the effects of four essential trace metals (Mn2+, Zn2+, Co2+ and Ni2+) with two toxic metals (Pb2+ and Cd2+) on Fe2+ uptake across the brush border membrane of villus-attached duodenal enterocytes. Everted rat duodenum was exposed to buffer containing 0·2 mM-59FE2+–ASCORBATE WITH OR WITHOUT THE COMPETING METAL (2 Mm) and the tissue was then processed for autoradiography allowing Fe2+ uptake to be determined at specific crypt–villus regions. The quantification method ensured that uptake by cells, rather than Fe2+ binding to the tissue surface, was measured. Fe2+ uptake was significantly inhibited by Cd2+ in upper villus enterocytes only and Pb2+ was without effect on Fe2+ uptake. The inhibition by Cd2+ was not due to general cell damage as judged by the release of lactate dehydrogenase from tissue into incubation fluid. Essential divalent trace metals reduced uptake significantly along the whole length of the crypt–villus axis. Cd2+ uptake, measured separately, took place at all regions of the villus–crypt axis, highest uptake being into crypt enterocytes. The very different uptake profiles for Cd2+ and Fe2+ suggests that the divalent metal transporter 1 is not the principal transporter of Cd2+. The addition of Fe2+ to incubation buffer inhibited Cd2+ uptake by both crypt and villus enterocytes. The possibility that the inhibitory actions of Fe2+ and Cd2+ on the uptakes of Cd2+ and Fe2+ respectively can be explained by a non-competitive action or the involvement of an additional metal transporter is discussed.
The intake of fried virgin olive or sunflower oils differentially induces oxidative stress in rat liver microsomes
Authors: Quiles José L. , Huertas Jesús R. , Battino Maurizio , Ramírez-Tortosa M. Carmen , Cassinello Modesta , Mataix José , Lopez-Frias Magdalena , Mañas Mariano
Published: July 2006

The effects of non-fried and fried virgin olive and sunflower oils on rat liver microsomal compositional features have been investigated. In addition, plasma antioxidants (α-tocopherol and ubiquinone 9) were investigated as well as the possible oxidative modifications suffered by virgin olive and sunflower oils during the frying process. The frying process decreased the content of α-tocopherol and phenolics in the oils and increased total polar materials. Sunflower oil was affected to a greater extent than olive oil. In rats, the intake of fried oil led to higher levels of lipid peroxidation and a lower concentration of plasma antioxidants. Microsomal fatty acid and antioxidant profiles were also altered. It seems that a strong relationship exists between the loss of antioxidants and the production of toxic compounds in the oils after frying and the extent of the peroxidative events in microsomes, which were also different depending on the fat source. The highly unsaturated sunflower oil was less resistant to the oxidative stress produced by frying and led to a higher degree of lipid peroxidation in liver microsomesin vivothan virgin olive oil.
The effect of consumption of foods that differ in energy density and/or sodium bicarbonate supplementation on subsequent diet selection in sheep
Authors: James Sarah M. , Kyriazakis Ilias
Published: July 2006

The short-term consumption of foods that differed in energy density (ED) and/or NaHCO3supplementation, on subsequent food intake and diet selection in sheep were measured. Thirty sheep weighing 35·9 (SD 2·89) KG WERE USED. TWO FOODS WERE FORMULATED: H HAD 11 AND L HAD 8 MJ METABOLIZABLE ENERGY/KG FRESH MATTER. FOUR FURTHER FOODS WERE FORMULATED BY ADDING EITHER 40 G NAHCO3/KG OR 16·5 G NACL/KG TO FOODS H AND L. NACL WAS ADDED TO GIVE THE SAME NA CONCENTRATION AS WITH 40 G NAHCO3/KG TO CONTROL FOR ANY EFFECTS OF NAPER SE. IN A PRELIMINARY TEST, IT WAS FOUND THAT A 2 H CONSUMPTION OF FOOD H SUPPLEMENTED WITH NAHCO3COULD BUFFER POTENTIAL IMPACT ON THE RUMEN ENVIRONMENT OF SUBSEQUENT CONSUMPTION OF FOOD H ALONE (AS JUDGED BY RUMEN PH AND ACID-BUFFERING CAPACITY); HOWEVER, IT WAS NOT AS EFFECTIVE AS THE CONSUMPTION OF FOOD L ALONE IN DOING SO. EACH FOOD TREATMENT WAS OFFERED TO ONE OF SIX GROUPS (N5) FOR 2 H FOLLOWING 16 H OF FOOD DEPRIVATION. SHEEP WERE THEN OFFERED A CHOICE BETWEEN H AND L FOR A FURTHER 6 H. SUPPLEMENTING H OR L WITH EITHER NAHCO3OR NACL HAD NO SIGNIFICANT EFFECT ON EITHER INTAKE OR DIET SELECTION. ED SIGNIFICANTLY (P<0·01) AFFECTED INTAKE DURING THE 2 H SINGLE FEEDING PERIOD, WITH SHEEP OFFERED H OR L CONSUMING 540 AND 663 (sed 37) g respectively, but had no effect on subsequent intake during the choice period. During the choice period all sheep showed a preference for food H, but sheep previously offered L selected significantly more H (0·873 g/g) than sheep previously offered H (0·544 (sed 0·028) g/g;P<0·001). It is concluded that short-term consumption of foods that differ in ED, and hence in their potential impact on the rumen environment, significantly affects subsequent diet selection. This is in agreement with the hypothesis that ruminant animals select a diet to help maintain the rumen environment within a certain physiological range. Food H with 40 g NaHCO3added/kg may not have been sufficient to affect subsequent diet selection. It is suggested that larger, rather than smaller, changes in the rumen environment achieved through previous feeding should be expected to alter subsequent diet selection.
Comparison of dietary and non-dietary risk factors in overweight and normal-weight Chinese adults
Authors: Hu Gang , Pekkarinen Heikki , Hänninen Osmo , Tian Huiguang , Jin Rongpei
Published: July 2006

The aim of the present study was to compare the differences in dietary and non-dietary factors contributing to normal weight and overweight among urban Chinese adults. Two cross-sectional population surveys were carried out in Tianjin, one of the largest cities in China. A total of 2631 subjects aged 25–64 years were selected by random stratified cluster sampling; 398 men and 490 women were overweight, and 886 men and 857 women were of normal weight. The diet was assessed by food weighing plus consecutive individual 3 d food records. Health-related behaviours and anthropometry were assessed. The overweight group had significantly higher mean daily intakes of energy and carbohydrate than the normal-weight group. Overweight men also had significantly higher mean daily intakes of protein and fat than normal-weight men. Age, daily intakes of energy and carbohydrate, and marital status were positively associated with overweight, while occupational and commuting physical activity, as well as smoking, were inversely associated with overweight among both genders. Daily intakes of protein, fat and alcohol were positively related to the incidence of being overweight among men. People with 7–12 years education were more likely to be overweight compared with those with less than 6 years of education. High intakes of energy and carbohydrate among both genders, as well as high intakes of protein and fat among men, and lower levels of occupational and commuting physical activity, being a non-smoker, and partly higher socio-economic status were related to a greater incidence of being overweight in this population.
Phytate degradation determines the effect of industrial processing and home cooking on iron absorption from cereal-based foods
Authors: Hurrell Richard F. , Reddy Manju B. , Burri Joseph , Cook James D.
Published: July 2006

The aim of the present study was to compare Fe absorption from industrially-manufactured and home-cooked cereal foods. Fe absorption was measured using the radiolabelled Fe extrinsic tag technique in thirty-nine adult human subjects from cereal porridges manufactured by extrusion cooking or roller-drying, and from the same cereal flours after home cooking to produce pancakes, chappattis or bread. One series of cereal porridges was amylase-treated in addition before roller-drying. Fe absorption was relatively low from all products, ranging from 1·8–5·5% for rice, 2·5–3·5% for maize, 4·9–13·6 % for low-extraction wheat, and <1% for high-extraction wheat foods. The phytic acid content remained high after drying of the cereal porridges being about 1·20, 1·70, 3·20, 3·30 mg/g in low-extraction wheat, rice, high-extraction wheat and maize products respectively, and could explain the low Fe absorption. There were little or no differences in Fe absorption between the extruded and roller-dried cereals, although amylase pre-treatment increased Fe absorption from the roller-dried rice cereal 3-fold. This was not due to phytate degradation but possibly because of the more liquid nature of the cereal meal as fed. There were similarly few or no differences in Fe absorption between the industrially-processed cereals and home-cooked cereals made into pancakes or chappattis. Bread-making, however, degraded phytic acid to zero in the low-extraction wheat flour and Fe absorption increased to 13·6%, the greatest from all cereal foods tested. It is concluded that Fe absorption from extruded, roller-dried or home-cooked cereal foods is similarly low and that only those cooking procedures such as bread-making, which extensively degrades phytic acid, or amylase pre-treatment, which substantially liquifies cereal porridges, improve Fe absorption.
Papaya (Carica papaya) consumption is unsafe in pregnancy: fact or fable? Scientific evaluation of a common belief in some parts of Asia using a rat model
Authors: Adebiyi Adebowale , Adaikan P. Ganesan , Prasad R. N. V.
Published: July 2006

Using controlled in vivo and in vitro pharmacological methods, we evaluated the safety of papaya (Carica papaya) consumption in pregnancy with reference to its common avoidance during pregnancy in some parts of Asia. Ripe papaya (Carica papaya L. (Caricaecae) blend (500 ml/l water) was freely given to four groups of Sprague-Dawley rats at different stages of gestation (days 1–5, 6–11, 12–17 and 1–20). The control group received water. The effect of ripe papaya juice and crude papaya latex on pregnant and non-pregnant rats' uteri was also evaluated using standard isolated-organ-bath methods. The daily volumes (ml) of ripe papaya blend consumed by the treated group were significantly (P<0·05) more than water consumed by the control (control 40·3 (SD 11·6) v. treated 64 (SD 19·0)). There was no significant difference in the number of implantation sites and viable fetuses in the rats given ripe papaya relative to the control. No sign of fetal or maternal toxicity was observed in all the groups. In the in vitro study, ripe papaya juice (0·1–0·8 ml) did not show any significant contractile effect on uterine smooth muscles isolated from pregnant and non-pregnant rats; conversely, crude papaya latex (0·1–3·2 mg/ml) induced spasmodic contraction of the uterine muscles similar to oxytocin (1–64 mU/ml) and prostaglandin F2α (0·028–1·81 μM). The response of the isolated rat uterine smooth muscles to 0·2 mg crude papaya latex/ml was comparable to 0·23 μM prostaglandin F2α and 32 mU oxytocin/ml. In the 18–19 d pregnant rat uterus, the contractile effect of crude papaya latex was characterized by tetanic spasms. The results of the present study suggest that normal consumption of ripe papaya during pregnancy may not pose any significant danger. However, the unripe or semi-ripe papaya (which contains high concentration of the latex that produces marked uterine contractions) could be unsafe in pregnancy. Though evaluation of potentially toxic agents often relies on animal experimental results to predict risk in man, further studies will be necessary to ascertain the ultimate risk of unripe papaya–semi-ripe papaya consumption during pregnancy in man.
Poor intestinal permeability in mildly stunted Nepali children: associations with weaning practices and Giardia lamblia infection
Authors: Goto Rie , Panter-Brick Catherine , Northrop-Clewes Christine A. , Manahdhar Renu , Tuladhar Nhuchhe R.
Published: July 2006

Studies in the Gambia, using the lactulose–mannitol dual-sugar intestinal permeability test (lactulose:mannitol ratio) as a non-invasive way of investigating mucosal damage, have shown that food malabsorption is significantly associated with early growth retardation. In this cross-sectional study, 210 poor urban Nepali children, 0–60 months old, were recruited and measured for height or length and weight, 167 were examined for intestinal permeability and 173 for parasite infection. Weaning and morbidity data were collected from 172 caretakers. Children were mildly stunted (mean height-for-age Z-score −1·45) and underweight (mean weight-for-age Z-score −1·62). The lactulose:mannitol ratio (0·26) was poorer than that of UK children (0·12), but similar to that found in Bengali children of the same age (0·24). Two stages of weaning, the onset supplementary feeding (6 months) and the cessation of breast-feeding (23 months), were shown to have differential impact. In children currently breast-feeding, the duration of supplementation was negatively related to lactose (P<0·001) and lactose:lactulose values (P<0·0001), indicating lactose maldigestion. In children who had ceased breast-feeding, a longer period of lactation was associated with poorer intestinal permeability (P=0·031), and poorer height-for-age (P=0·024), which was an unexpected result. No significant relationships were found between intestinal permeability and growth, or with morbidity and helminth infection, except in children withGiardia lambliawho had worse lactulose:mannitol ratios than those without (0·43v.0·25 respectively,P=0·014). It is likely that insults to the gut (e.g. Giardia) and challenges to the immune system (weaning) have a different impact in early and late infancy.