The effects of maternal intake and gestational age on materno-fetal transport of vitamin C were investigated in female Dunkin-Hartley guinea-pigs. Twenty-four time-mated dams were fed on either a moderate-vitamin C (group A) or a high-vitamin C (group B) diet, throughout pregnancy. At days 49, 63 and 66 of gestation, and at term, three animals from each group were killed and fetuses removed by hysterectomy. Plasma, liver, kidney, lungs, heart, placenta and amniotic fluid were collected from dams and fetuses and subsequently analysed for vitamin C. Fetal plasma and amniotic fluid concentrations showed negative associations with gestational age for both dietary groups, independent of an effect of dam (P < 0.001). A similar, though not significant, effect of gestational age was observed on placental vitamin C and group A fetal tissue concentrations. Fetal plasma, placental and amniotic fluid vitamin C concentrations were significantly higher in group B than group A (P < 0.001), suggesting the influence of maternal diet. Although the level of maternal vitamin C intake can influence the circulating concentration in the fetus, there is a decrease associated with increasing gestational age, independent of the maternal diet. The gestational age-dependent change in the fetal accumulation of vitamin C may reflect changes in the rate of placental transfer.

The amount of dietary trace elements absorbed from a meal depends, among other factors, on the quantities of certain minor plant constituents present in the meal. These substances can act as ligands and bind trace elements in the digestive tract in available or unavailable forms for absorption. The present study was designed to investigate the extent to which different polyphenols (PP) may influence Zn and Cu absorption in rats. Different PP of nutritional interest (chlorogenic acid, caffeic acid, catechin and rutin) were studied using meals extrinsically-labelled with stable isotopes67Zn and 65Cu. Male Wistar rats were fed on a non-labelled semi-synthetic diet containing (mg/kg) 38 Fe, 35 Zn and 7·5 Cu for 8 d. PP were dissolved in dimethyl sulfoxide as the solvent and added to the meal at 1 g/kg during 3 d before isotope administration and until the end of the experiment (a further 3 d). The control group received the dimethyl sulfoxide only. After overnight food deprivation, rats were fed on the labelled test meals (4 g diet+0·1 mg 67Zn and 0·1 mg 65Cu) with 0·5 mg Dy as a faecal marker. Faeces and urine pools were collected for 3 d and analysed for 67Zn and65 Cu isotopic enrichment using the inductively-coupled plasma mass spectrometry technique. Zn absorption was significantly less in rats fed on chlorogenic acid or caffeic acid than in the control group. Catechin ingestion non-significantly inhibited 67Zn absorption. However, the PP studied were without effect on Cu absorption. The study illustrates the effect of metal-binding phenolic compounds on mineral nutrition in the rat, and the possible importance of the effects of different foods rich in these compounds on mineral absorption in man.

We studied glucose homeostasis in rat pups from dams fed on a normal-protein (170 g/kg) (NP) diet or a diet containing 60 g protein/kg (LP) during fetal life and the suckling period. At birth, total serum protein, serum albumin and serum insulin levels were similar in both groups. However, body weight and serum glucose levels in LP rats were lower than those in NP rats. At the end of the suckling period (28 d of age), total serum protein, serum albumin and serum insulin were significantly lower and the liver glycogen and serum free fatty acid levels were significantly higher in LP rats compared with NP rats. Although the fasting serum glucose level was similar in both groups, the area under the blood glucose concentration curve after a glucose load was higher for NP rats (859 (sem 58) mmol/l per 120 min for NP rats v. 607 (sem 52) mmol/l per 120 min for LP rats; P < 0.005). The mean post-glucose increase in insulin was higher for NP rats (30 (sem 4.7) nmol/l per 120 min for NP rats v. 17 (sem 3.9) nmol/l per 120 min for LP rats; P < 0.05). The glucose disappearance rate for NP rats (0.7 (sem 0.1) %/min) was lower than that for LP rats (1.6 (sem 0.2)%/min; P < 0.001). Insulin secretion from isolated islets (1 h incubation) in response to 16.7mmol glucose/l was augmented 14-fold in NP rats but only 2.6-fold in LP rats compared with the respective basal secretion (2.8 mmol/l; P < 0.001). These results indicate that in vivo as well as in vitro insulin secretion in pups from dams maintained on a LP diet is reduced. This defect may be counteracted by an increase in the sensitivity of target tissues to insulin.

Excessive interferon-gamma (IFN-γ) production appears to be a primary immunological lesion in vitamin A-deficient experimental animals but comparable data from humans is lacking. We investigated IFN-γ production in South African children by measurement of urinary excretion of neopterin, a product of IFN-γ-activated monocytes or macrophages. Preschool children were examined during an acute inflammatory illness resulting from accidental ingestion of kerosene and they and a neighbourhood control child were examined 3 months later when well. Vitamin A status was assessed by the modified relative dose response (MRDR) test at 3 months and serum retinol and acute phase proteins were measured at both time points. Urinary neopterin was measured for forty cases in hospital, forty-six cases after recovery, and forty-one controls. Significantly increased neopterin excretion was seen following kerosene ingestion and in association with raised serum acute phase protein concentrations. There was no relationship between neopterin excretion at either time point and vitamin A status as assessed by MRDR test. Urinary neopterin was negatively correlated with serum retinol but no significant relationship was observed when acute phase protein concentrations were included in a multiple regression, suggesting the correlation was secondary to illness-induced changes in serum retinol. The results indicate that, contrary to what is observed in rodents under experimental conditions, poor vitamin A status is not associated with altered regulation of IFN-γ production in children.

Male Wistar rats were fed on a conventional diet containing normal corn starch or 6 % enzyme-resistant starch originating from either raw or retrograded high-amylose corn starch. Furthermore, the diets were either cholesterol-free or contained 1 % cholesterol and 0·1 % cholic acid. The main objective of this study was to investigate whether the addition of enzyme-resistant starch to a rat conventional diet had any effect on cholesterol metabolism. Therefore, plasma and liver cholesterol concentrations, plasma HDL:LDL cholesterol ratios and neutral steroid and bile acid excretion were determined. No significant effect of enzyme-resistant starch feeding on plasma and liver cholesterol concentrations was found. However, consumption of raw or retrograded high-amylose corn starch resulted in a decrease in esterified and total liver cholesterol concentrations of 24 and 22 %, respectively. This was accompanied by a reduction in plasma esterified and total cholesterol levels of 4 % and a tendency to higher daily faecal coprostanol and total bile acid excretion.

The present study examined whether the intestinal microflora could affect the bioavailability and vitamin A activity of dietary α- and β-carotene in the rat. In the first set of experiments, we used conventional, germ-free (axenic), and human-flora-associated (heteroxenic) rats. In a second series, conventional rats were treated with either an antibiotic mixture or a potent inhibitor of gastric secretion (Omeprazole). All animals were first depleted of vitamin A over 4 weeks and then were fed on a sterilized diet supplemented with 14 mg β-carotene and 3 mg α-carotene/kg for 2 weeks. In both experiments, a reduction in the intestinal microflora resulted in an increased storage of β-carotene, α-carotene and vitamin A in the liver. Neither the nature of the metabolism of the intestinal microflora (aerobic or anaerobic) nor treatment with omeprazole, to modify intestinal pH, induced a significant effect on the measured variables. When incubated with 15 μmol β-carotene/l for 72 h, neither the anaerobic nor the aerobic sub-fractions obtained from rat or human faeces contributed to β-carotene degradation or to vitamin A synthesis. These findings suggest that reduction in gut microflora results in a better utilization of α- and β-carotene by rats, although bacteria do not have a direct effect on the bioavailability of these pigments.

We evaluated the accuracy of self-reported home-assessed and self-measured waist circumference in 101 men and eighty-three women aged 28–67 years. The main outcome measures were subjects' self-reported and self-measured waist circumference, and self-classification according to the previously defined waist action level 1 (940 mm in men, 800 mm in women) and action level 2 (1020 mm in men, 880 mm in women), and waist circumference measured by the investigator using the ‘Waist Watcher’ tape-measure, as the reference method. The mean errors (95% CI limits of agreement) for subjects' self-reported waist circumference (self-reported minus reference; mm) were −67 (95% CI −210, 77) in men and −43 (95% CI −211, 123) in women, and for self-measured waist circumference (mm) using the ‘Waist Watcher’ (self-measured minus reference) were −5 (95% CI −62, 52) in men and −4 (95% CI −50, 42) in women. The proportions of subjects classified into waist action level 1 or action level 2 by the investigator were used as the reference method. Self-reported waist circumference of men and women respectively would be classified correctly in different categories based on action level 1 with sensitivities of 58·3 and 78·7%, and specificities of 98·5 and 98·7%, and action level 2 with sensitivities of 38·3 and 48·9%, and specificities of 98·5 and 98·7%. Using the ‘Waist Watcher’ with different colour bands based on the action levels, male and female subjects respectively classified themselves into correct categories according to action level 1 with sensitivities of 100 and 98·7%, and specificities of 98·1 and 98·2%, and according to action level 2 with sensitivities of 98·1 and 100%, and specificities of 100% for both sexes. Only 2% of the sample misclassified themselves into the wrong categories according to waist circumference action levels. In conclusion, people tend to underestimate their waist circumference, but the ‘Waist Watcher’ tape-measure offers advantages over self-reported home-assessed measurement, and may be used as a screening tool for self-classifying the risk of ill health through intra-abdominal fat accumulation.

Increasing the energy value of diets with dietary fat, particularly fats rich in saturated fatty acids, can result in the elevation of plasma total and lipoprotein cholesterol. In the present study, experimental diets were designed to examine the effects of increasing the energy content of diets with a saturated fat source and cholesterol in a non-purified diet on hyperlipoproteinaemia and aortic plaque composition in the atherosclerosis-susceptible Japanese quail (Coturnix japonica) model of human atherosclerosis. Commercial poultry diets containing two levels (i.e. 60 or 120 g/kg) of beef tallow as the primary source of saturated fat were balanced for endogenous cholesterol or supplemented with cholesterol (i.e. 0·5 or 5·0 g/kg) and fed to quail for 9 weeks to examine the effects on whole plasma, lipoprotein and aortic plaque lipid composition in relation to aortic plaque formation. Hypercholesterolaemia (P<0·001) was confirmed in birds fed on high-cholesterol (HC) diets only. An interaction (P=0·05) between dietary cholesterol and fat intake level was observed for plasma triacylglycerols (TG) and was specific to changes observed in VLDL composition. Diet-induced changes in lipoprotein total cholesterol, TG and phospholipid composition were greatest in the portomicron and VLDL fractions in birds fed on atherogenic diets. Hyperlipoproteinaemia induced by the 60 g/kg added beef tallow–HC diet resulted in significant (P<0·001) aortic plaque deposition, which was further enhanced in birds fed on the 120 g/kg beef tallow–HC diet. Quail fed on 120 g/kg beef tallow-HC diets exhibited the most severe aortic plaque formation, with marked increases in aortic tissue cholesterol content and quantifiable amounts of several cholesterol oxides (5,6α-epoxy-5α-cholesterol, 7β-hydroxycholesterol, cholestanetriol, 7-ketocholesterol and 25-hydroxycholesterol). In summary, hyperlipoproteinaemia associated with HC diets with a greater proportion of energy from saturated fat produced a combined effect in altering plasma and lipoprotein lipid composition as well as aortic tissue cholesterol and cholesterol oxide content in the Japanese quail.

The gastrointestinal absorption and organ distribution of Cd after exposure for 9 weeks to three fibre-rich foodstuffs (wheat bran, sugar-beet fibre and carrots) were determined in mice. Groups of eight mice were given a diet containing 0.05 mg Cd/kg from wheat bran, sugar-beet fibre, carrots or CdCl2 mixed in a semi-synthetic, low-Cd (<0.007mg/kg) feed. A control group was fed on the low-Cd semi-synthetic feed. The water consumption, food consumption and the weight of the animals were monitored throughout the study. The feed was changed once weekly and Cd was analysed in the feed at each change. myo-Inositol phosphates (hexa-, penta-, tetra- and tri-) and Zn, Cu, Fe and Ca were also analysed in the diets. After 9 weeks, the mice were killed and liver and kidneys were sampled and analysed for Cd. The group receiving the wheat-bran diet had significantly lower fractional Cd accumulation (% total Cd intake) in the liver and kidneys than the other groups, indicating a lower fractional absorption of Cd. The wheat-bran diet had markedly higher levels of inositol hexa- and pentaphosphates (phytates) and a Zn level that was twice as high as those in the other diets. The higher levels of myo-inositol hexa- and pentaphosphates in the wheat-bran diet most probably contributed more to the lower fractional absorption of Cd than the elevated Zn level, due to the formation of insoluble Cd–phytate complexes. Compared with the wheat-bran diet, the sugar-beet-fibre and carrot diets contained very low levels of myo-inositol penta- and hexaphosphates, and consequently the fractional Cd absorption from these diets was higher.

Acetylation is a potential method for protecting dietary peptides from degradation by rumen micro-organisms. As a first step in determining the nutritive value of acetylated peptides, their disappearance in the small intestine of sheep and their ability to support growth in a rat bioassay were measured. 15N-labelled peptides were prepared from lucerne which had been grown with 15N-labelled (NH4)2 SO4 in the absence of Rhizobium. Peptides were prepared by enzymic hydrolysis of the extracted protein. Two peptide preparations were made using different proteinase mixtures. These mixtures contained peptides with an average molecular weight of 559 and 522 Da. They were treated with acetic anhydride, which resulted in 85 and 88% modification respectively, and their uptake from the small intestine was determined by injecting 1 g of untreated or acetylated peptides in a Cr-EDTA solution into the jejunum of two sheep fitted with jejunal catheters and ileal cannulas. Ileal digesta were collected and analysed for Cr and 15N. The uptake of dialanine (Ala2) and N-acetyl-Ala2 were compared in a similar way. The disappearance of 15N from lucerne peptides was high (88 and 93% respectively) and this was not affected significantly by acetylation (86 and 87%). Corresponding values for Ala2 and N-acetyl-Ala2 were both 96%, as measured by HPLC. It was therefore concluded that acetylation did not affect the uptake of peptides from the small intestine in sheep. Two feeding trials were carried out with rats. The first trial was carried out with a protein-free diet to which was added 10% lactalbumin or 5% lactalbumin and then a mixture of methionine-free amino acids, either alone or supplemented with Met, Gly-Met or acetylated Gly-Met. The rats grew equally well on all sources of Met, but failed to grow significantly on the mixture of Met-free amino acids. In the second trial the diet contained casein as 5·9% of the basal diet. Additional casein, pancreatic casein hydrolysate (peptides) and acetylated pancreatic casein hydrolysate (acetylated peptides) were compared as sources of amino acids, at inclusion rates of 100 g/kg final diet. Feed intake was similar with casein and peptides treatments, but was depressed by 23% with acetylated peptides. Live weight gain was 15 and 75% lower with the peptides and acetylated peptides diets respectively. Addition of lysine, arginine or histidine did not restore feed intake or weight gain of rats receiving acetylated peptides, but feed intake was restored immediately when peptides replaced acetylated peptides. When intake was restricted to 9 g/d and acetylated casein hydrolysate replaced half of the protein in the diet, rats gained weight less rapidly (1·44 v: 1·09 g/d) and retained less N, such that only 0·36 of the acetylated peptide-N was calculated to remain available to the animal. This N retention compared with 0·70 for unmodified casein. Thus, the rat bioassay indicated that certain specific peptides may well be of high nutritive value following acetylation, but that there may be problems of inappetance and inefficient utilization with acetylated peptide mixtures.

Agrimony eupatoria (agrimony) has been documented as a traditional treatment of diabetes. Here, the effects of dietary administration of agrimony on streptozotocin (STZ)-diabetic mice and on in vitro glucose uptake and glucose metabolism, and on insulin secretion by BRIN-BD11 cells were investigated. Agrimony incorporated into the diet (62·5 g/kg) and drinking water (2·5 g/l) countered the weight loss, polydipsia, hyperphagia and hyperglycaemia of STZ-diabetic mice. Aqueous extract of agrimony (1 mg/ml) stimulated 2-deoxy-glucose transport (1·4-fold), glucose oxidation (1·4-fold) and incorporation of glucose into glycogen (2·0-fold) in mouse abdominal muscle comparable with 0·1 μM-insulin. In acute 20 min tests, 0·25-1 mg/ml aqueous extract of agrimony evoked a stepwise 1·9–3·8-fold stimulation of insulin secretion from the BRIN-BD11 pancreatic B-cell line. This effect was abolished by 0·5mM-diazoxide and previous exposure to extract did not adversely affect subsequent stimulation of insulin secretion by 10 mM-L-alanine, thereby indicating that there was no detrimental effect of the extract on cell viability. The effect of extract was glucose-independent and was not evident in BRIN-BD11 cells exposed to a depolarizing concentration of KCl. The ability of agrimony extract to enhance insulin secretion was dependent on use of heat during extract preparation. These results demonstrate the presence of antihyperglycaemic, insulin-releasing and insulin-like activity in Agrimony eupatoria.