摘要:

Oral calcium supplementation is thought to be a useful interventional agent to decrease colon cancer risk. This is supposedly due, at least in part, to the binding of bile acids and fatty acids by calcium in the colon, thus prohibiting the damaging effects of these substances to the epithelium. To determine the effects of calcium supplementation on fecal fat excretion, 24 subjects kept a fat and calcium constant diet for one week and were supplemented with either 0, 2 or 4 g elemental calcium as calcium carbonate in a double-blind fashion. At the end of the week 72-hour feces was collected, and total fat, neutral fat, fatty acids and the ratio of polyunsaturated and saturated fatty acids (P/S ratio) were measured. Calcium dose-dependently increased the percentual excretion of total fat as related to fat intake: 6.8 ± 0.9% during Og, 7.4 ± 1.0% during 2 g and 10.2 ± 1.4% during 4 g, r = 0.44, p = 0.03. This was due to increased fatty acid excretion, excretion of neutral fat was not affected, nor was the P/S ratio. It is concluded that calcium supplementation modestly increases fecal fatty acid excretion. No adverse metabolic effects are to be expected from this in case of long-term calcium supplementation in subjects at increased risk for colon canc

ISSN:0250-6807    

DOI:10.1159/000177810

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The iron status of a representative population sample in a district of Paris area (France) was assessed using a biochemical and dietary approach. Complete data were obtained for 1,108 subjects 6 months to 97 years old. Total iron intake increased up to adolescence and then remained stable in adult life. Iron intake was higher in men than in women. Most children and menstruating women presented a dietary iron intake below the recommended allowances. While anemia was not very common, iron deficiency (defined as the existence of at least two abnormal values in the four independent indicators of iron status: serum ferritin, erythrocyte protoporphyrin, transferrin saturation and MCV) was particularly common in infants, young children, menstruating women and elderly men. Serum ferritin, erythrocyte protoporphyrin and transferrin saturation were significantly correlated with inflammatory markers. Significant correlations were found between dietary total iron and serum ferritin (r = 0.29, p < 0.001) and hemoglobin (r = 0.44, p < 0.001). After adjustment for age, sex and inflammation, using multiple linear regression models, the relationship between both heme and nonheme iron intake and serum ferritin remained significant. Serum ferritin and hemoglobin levels were negatively correlated with calcium and phosphorus intake.

ISSN:0250-6807    

DOI:10.1159/000177811

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Four diets containing different mixtures of dietary fibre (DF) were tested in the rat to verify the effects of fibre source and fibre level on plasma glucose, insulin and lipids and on apparent intestinal absorption of minerals. Diets Puri5 and Puri 10 contained 5 and 10% of total DF from pectin and cellulose. Diets Bran 5 and Bran 10 supplied 5 and 10% DF from oat bran and wheat bran. A fifth diet with 5 % cellulose was used as a control. Ten rats were fed each diet for 4 weeks. On days 3, 17 and 28, feces were collected and analyzed for Fe, Zn, Ca and Mg. On day 29, blood samples were collected in portal vein and abdominal aorta in fasted and fed rats from each group. All diets had similar effects on plasma insulin and triglycerides. Compared to Bran diets, Puri diets induced higher portal glucose (p < 0.01) and lower plasma cholesterol ( p < 0.03) in fed rats. The apparent absorption of Fe, Zn and Mg was higher (p < 0.05) in rats fed Puri diets than in those fed Bran diets. For Ca, the difference was significant only on day 3. In this study, only the apparent absorption of Fe was affected (p 10%). This indicates that in fibre mixtures, the source rather than the amount of fibre generally affects absorptive and metabolic parameters.

ISSN:0250-6807    

DOI:10.1159/000177812

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Phenobarbital (PB)-induced activities of the liver microsomal mixed-function oxidase (MFO) system in response to dietary levels of n-3 fatty acids were investigated in rats. The MFO activities were assessed by the contents of cytochromes P-450 and b5, and the activities of NADPH-cytochrome c reductase, aminopyrine N-demethylase and aniline hydroxylase. A linoleic acid (C18:2, n-6; LA) diet (2.0 energy % as LA) and n-3 fatty acid diets (0.3,1.0, 1.9 or 4.8 energy % as n-3 fatty acids) were fed to rats for 16 days. The activities of MFOs except that of NADPH-cytochrome c reductase increased, as compared with the LA diet, with increasing the dietary n-3 fatty acid level, concomitant with the increase in n-3 fatty acids and decrease in n-6 fatty acids in liver microsomal lipids. The dietary LA over 1.8 energy % up to 13.8% did not increase the activities of PB-induced MFOs. Consequently, dietary n-3 fatty acids further elevated the PB-induced MFO activities effectively. These results suggest a differential response of dietary n-6 and n-3 fatty acids to the PB-induced MFO activities.

ISSN:0250-6807    

DOI:10.1159/000177813

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

This study concerns in vivo folic acid and methyltetrahydrofolic acid (MTHF) absorption by the whole intestinal surface after 20 weeks of 30% ethanol ingestion in drinking water. The results were compared with control rats fed ad libitum. The total intestinal serosal areas were similar in ethanol-fed and control rats. Significant increases in intestinal length, and decreases in tissue wet and dry weights were found in ethanol-fed rats. Serum folic acid concentrations were significantly less in the animals which had ingested ethanol than in the control rats. Intestinal folic acid absorption was significantly increased at lower substrate concentrations (0.5 and 1 µM), while no difference was observed at 2.5 µM in the ethanol-fed rats. Folic acid absorption relative to tissue wet weight showed significant increases at all tested concentrations in the ethanol-fed rats. Intestinal MTHF absorption showed no significant changes at 0.5 µM MTHF concentration, and an increase was observed in the absorption values at 1 and 2.5 µM concentrations in the ethanol-fed rats. When expressed as tissue wet weight, MTHF absorption values in ethanol-fed rats increased at 1 and 2.5 µM but did not differ at 0.5 µM substrate concentrations. The above results indicate compensatory responses in the folic acid and MTHF intestinal absorption after chronic ethanol ingestion. These effects are observed when the whole intestinal surface is eval

ISSN:0250-6807    

DOI:10.1159/000177814

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Black and green tea decoctions are popular beverages in Tunisia, especially after eating. Our study was performed to examine the effect of graded amounts of black and green tea decoction prepared under realistic Tunisian conditions on nonheme iron absorption from a typical Tunisian meal, ‘couscous’, by extrinsic radioiron labeling in rats. Concentrations of 300,200 and 100 µg/ml of black tea decreased dramatically nonheme iron bioavailability from couscous, but 50 µg/ml did not influence iron absorption. The inhibition of nonheme iron from couscous varied from 36 to 61% with black tea and 30.5% with green tea. Taken together, our findings show that the tea decoction in Tunisia has a great inhibitory power and may constitute an important factor for the development of iron deficiency anemia throughout Tu

ISSN:0250-6807    

DOI:10.1159/000177815

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

This research was designed to evaluate the circadian variation in the lipid content of the milk obtained from 10 lactating Mexican women as well as the effects of a meal eaten by the mother and of previous milk sampling on the milk volume and fat yield. In addition, predictions were made to determine the most appropriate sampling schedule to obtain a milk sample representative of 24-hour production. Every 4 h over a 24-hour period, the contents of the left breast of predominantly breastfeeding volunteers were completely extracted, using an Engell pump, and analysed for lipid content. In a separate experiment, 6 volunteers were sampled hourly from 9.00 to 13.00 h on 2 consecutive days, one after eating breakfast and the second while fasting. Significant circadian variations of volume (p < 0.05) and lipid yield (p < 0.001) were noted, peaking at 8.00-12.00 and 16.00-20.00 h, respectively. No effects of eating breakfast or of the volume and fat content of the preceding pumping on the actual volume or fat yield were found. In this population, sampling at 12.00, 20.00 and 24.00 h is the most representative of the 24-hour lipid yield, tending to overestimate it by 2.59 g/24 h with a predictive range of 97-124%.

ISSN:0250-6807    

DOI:10.1159/000177816

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

We evaluated the rat cirrhosis model obtained by repeated intraperitoneal administration of CCl4 (group C) with regard to biological and nutritional conditions in comparison to ad libitum (group AL) and pair-fed control rats. Cirrhotic rats were divided into two groups according to their clinical condition: group C1 (n = 4) represented those in good physical condition and group C2 those (n = 10) in poor physical condition. Autopsy indicated that rats in group C2 suffered from severe malnutrition as judged by body weight, carcass weight and the carcass/body weight ratio. However, all 14 treated rats presented the same micronodular cirrhosis and the same alterations in liver function, except for alkaline phosphatase activity (group C1: 110 ± 63 IU/1, group C2: 259 ± 110 IU/1; p < 0.05). In the cirrhosis groups, plasma levels of branched-chain amino acids (BCAA) and the BCAA/aromatic amino acid (AAA) ratio were significantly reduced, but values in groups Cl and C2 were not significantly different (BCAA/AAA: 1.9 ± 0.9 in group C1, 1.5 ± 0.8 in group C2, 2.8 ± 0.3 in group AL; C1 and C2, vs. AL: p < 0.05). These alterations were similar to those observed in human cirrhosis and were not solely the result of reduced food intake, as indicated by the lack of difference between pair-fed and ad libitum-fed control

ISSN:0250-6807    

DOI:10.1159/000177817

出版商:S. Karger AG    

年代:1994

数据来源: Karger