Nutrition and metabolism最新文献

The concentration of folate in human milk was estimated in two groups of lactating mothers. The first group had no folate supplementation throughout pregnancy and the other group had 5 mg folate/day throughout the last trimester. Concentration of folate was significantly higher in the milk of mothers who had supplementation. There was a significant increase in folate concentration as the milk progressed to maturity. When malaria was present, there was no significant increase in the concentration of folate in the milk. Human milk is low in folate, and a rise in body temperature seems to disturb folate metabolism.

Plasma and bile lipids and in vitro cholesterol esterifying activity of plasma (mg CE/dl/6 h) were determined in healthy volunteers who supplemented their regular diets with 7.5 g doses of soya lecithin three times daily for a 4-week period. Lecithin ingestion by the 4 male and 6 female subjects did not produce any significant changes either in total plasma cholesterol (TC) level or cholesterol esterification. A small but significant reduction was observed in the plasma triglyceride (TG) and total phospholipid (TPL) levels after supplementation. The molar percent of bile acids (BA), TC and TPL as well as the lithogenic index (LI = TC/BA + TPL) in both hepatic and gallbladder bile were also unaltered by 4 weeks of lecithin supplementation. In vitro cholesterol esterification was found linearly related to plasma-free cholesterol (r = 0.60, p less than 0.01) cholesterol ester (r = 0.50, p less than 0.05), total phospholipid (r = 0.50, p less than 0.05), lecithin (r = 0.45, p less than 0.05), and triglyceride (r = 0.57, p less than 0.025) levels.

Availability of magnesium and some trace elements in Indian diets has been studied in human adults. Absorption of trace elements from the diets as a percentage of intake was: chromium 60, copper 18, magnesium 34, manganese 14 and zinc 16. Daily dietary intakes of 51.5 micrograms of chromium, 1.73 mg copper and 4.1 mg of manganese were found to be necessary to keep the subjects in balance in respect to these elements.

Adult rats fed a diet containing 14%, by weight, of protein displayed a negative N balance when energy intake was reduced to a value approximating basal metabolism. A positive N balance was induced, however, by raising the protein concentration in the diet, and N retention continued until body fat reserves were almost exhausted. These findings are in conflict with the widely-held view that N equilibrium can be achieved only when the need for energy is satisfied.

Used frying oil can be separated by means of column chromatography on silica gel into an unpolar fraction, which contains predominantly the unaltered triglycerides, and a polar fraction consisting of all oxidation and decomposition products formed during the heating process. The size of the polar fraction indicates the degree of fat deterioration. A similar procedure was applied to obtain fractions from a heated oil to be used in long-term feeding experiments. Several tons of a sunflower oil which had been used in the industrial production of fish fingers were separated into a polar fraction (1) and an unpolar fraction (2). The sunflower oil had not been overheated and was taken at the moment when the production would have been stopped, according to factory practice, and the oil discarded. Fractions 1 (group U) and fraction 2 (group P) as well as the original unheated sunflower oil (group F) and the heated sunflower oil (group H) were fed to rats over 18 months at a level of 20% in the diet. Fraction 1 caused a highly significant reduction in weight gain of the animals as compared with unheated sunflower oil but had only an insignificant detrimental effect upon the many biochemical, histological and clinical parameters. The order of the weight gain caused by the four samples was: U < H < P < F. The changes of other parameters as well as the implications of these long-term feeding studies will be discussed in detail.

Although the intake of saturated facts still appears to be the environmental factor most closely associated with coronary heart disease (CHD), this does not necessarily mean that CHD is caused essentially or solely by blood lipids, as suggested by several investigators. It seems that blood platelets rather than (or at least in addition to) blood lipids might be the intermediate link between certain environmental factors (saturated fats, hard water) and CHD, through an effect on both thrombosis and atherosclerosis. Our recent studies in French and Scottish farmers, have shown that blood platelet function is more drastically affected by saturated fats than blood lipids. In those studies, platelet function was the only blood parameter correlated on an individual basis with the intake of saturated fat and inversely related to calcium intake. Calcium is probably the cation responsible for the protective effect of hard water against CHD in various countries. The results obtained also indicate that platelet function can be improved by increasing the intake of polyunsaturated fats at the expense of saturated fats. Finally, only platelet function was different from one region of France to another and from our region of Scotland to another; this difference could be related to the reported incidence of CHD in these various regions.

Encephalopathy was induced in 14-day-old chicks by a vitamin E-deficient diet containing 15% thermally oxidized safflower oil. Bound acid phosphatase activity in the cerebellum was markedly lower in affected chicks than in vitamin E-supplied control chicks. Free activity also tended to be lower in the deficient group. There were no differences in enzyme activities of cerebrum and liver between deficient and control chicks.

By means of food diaries the volume of the average daily crude fiber and dietary fiber consumption and the percentage contribution of various groups of plant foods to the total dietary fiber consumption was determined in a group of 150 healthy subjects (89 males and 61 females) from four different occupational groups. It thus became apparent that the mean daily dietary fiber consumption was 22.0 +/- 5.5 g in the artisians and workers of a large industrial plant (group I), 24.8 +/- 8.4 g in students (group II), 21.7 +/- 5.5 g in teachers (group III), and 17.6 +/- 7.7 g in administrative employees (group IV). In groups I-III the mean daily dietary fiber consumption was significantly higher than in group IV. In 17% of the subjects, the mean daily dietary fiber consumption was < 15 g. The mean dietary fiber intake per 1,000 kcal (4.18 MJ) in groups II and III, 8.5 +/- 1.5 and 8.8 +/- 2.2 g, respectively, was significantly higher than in group I with a mean fiber intake of 7.2 +/- 1.4 g.

A fed and a starved group of mice were injected with a 14C-labelled triolein emulsion, similar to Intralipid, in a dose corresponding to 0.1 mg triglyceride per gram body weight. The animals were sacrificed from 30 sec to 24 h after injection. The tissue distribution of the fat emulsion depended on the nutritional state of the animals. A marked concentration of radioactivity was found in the gastric mucosa of all animals as soon as 30 sec after injection which declined with time but was still clearly discernible in the autoradiograms 24 h after injection. Although the radioactivity only demonstrates the presence of the labelled oleic acid without indication of the degree of triglyceride lipolysis, the autoradiograms showed marked differences in the concentration of radioactivity between the various groups of skeletal muscles and between the different parts of the reticulo-endothelial system.

16 normal male adult volunteers belonging to the low socioeconomic class were investigated to study the interrelationship between vitamins E and B-complex. Vitamin E in the form of dl-alpha-tocopherylacetate at a dose of 100 mg thrice daily was administered either singly or in combination with B-complex, pyridoxine or riboflavin. Results of the study have shown that the increase in plasma tocopherol level in the group receiving vitamin E alone was significantly higher (p less than 0.01) compared to the groups receiving vitamin E along with B-complex or riboflavin.