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H H Sandstead

Publications and source records attributed to H H Sandstead.

At least 55 records · Page 3Linked to original sources
PubMed1986

A brief history of the influence of trace elements on brain function.

From this brief review of history it is evident that lead, mercury, iodine, cobalt, iron, copper, manganese, and zinc have important influences on brain development and function. Identity of thresholds at which effects occur is needed for determination of safe and/or essential levels of these elements in diets. Such knowledge will help define human needs for essential elements, and the hazards of toxic elements.

Animals↗
PubMed1986

Effect of browned and unbrowned corn products intrinsically labeled with 65Zn on absorption of 65Zn in humans.

Experimental browned and unbrowned corn products were formulated and processed from unenriched, degermed yellow corngrits. The browned product (cornflakes) contained more insoluble dietary fiber and bound more zinc (in vitro) than the unbrowned product (corngrits). During processing some of the cornflakes and corngrits were combined with a small amount of yellow corn endospermhull intrinsically labeled with 65Zn. The intrinsically labeled corn products were fed, in a crossover design, as components of two breakfasts to six normal, unconfined volunteers. Each volunteer absorbed more 65Zn from the corngrits than from the cornflakes. The reduced 65Zn absorption from cornflakes was attributed to heating and toasting reaction products, possibly Maillard, which bound zinc and consequently made the zinc less available for absorption.

Absorption↗
PubMed1985

Requirement of zinc in human subjects.

Essentiality of zinc in nutrition of higher animals was established in 1934. Dietary zinc deficiency in humans was recognized in 1961. Dietary requirements for zinc have been estimated factorially and by balance studies. Factors that influence dietary zinc requirement include dietary and other substances that either facilitate or inhibit absorption and retention of zinc; and metabolic phenomena that influence retention or excretion of the element. These determinants must be considered in estimating the requirement and the recommended dietary allowance for this essential element. An approach that has been used to assess requirement is the measurement of dietary zinc retention by men fed diets providing sufficient energy to meet the needs of each individual and containing other nutrients in proportion to energy content. By measurement of chemical balance and subsequent analysis of the data by multiple regression, dietary factors influencing requirement have been identified and amounts of dietary zinc essential for needs calculated. Using this approach, 83% of the variance (P less than 0.0001) in requirement was accounted for by the dietary content of phosphorus and nitrogen when data from 157 twenty-eight to thirty day studies were analyzed. The equation, Intake = 1.466 + 0.23 (Zn balance) + 5.19 (P intake) + 0.40 (N intake) - 0.30 (P intake - 1.389) (N intake - 14.646), was used to estimate zinc requirement of persons who participated in the most recent USDA Food Consumption Survey. For all age groups, ages 9 to greater than 75y, males and females, the mean (range) difference between the estimated intakes and calculated requirements were: males 1.5% (-6.5 to + 8.1), females 11.3% (- 1.1 to + 20.3). Thus, mean intakes were generally within the 95% confidence limits of the estimated requirements. Of some interest was the finding that the mean intake of none of the groups was equivalent to the Recommended Dietary Allowance. The mean intake of males ranged from 9.32 mg in men 75y and older to 13.53 mg in persons 15-18y. The mean intake of the females ranged from 7.04 mg in women 75y and older to 9.22 mg in persons 12-14 y.

Adolescent↗
PubMed1985

Mineral contents of brans passed through the human GI tract.

Concentrations of Cu, Fe, Zn, Ca, and phytate were measured in dry-milled corn bran, wheat brans, and soybean hulls prior to being baked in bread and after passage through the human GI tract. Significant changes in mineral concentrations in the retrieved remnants compared to the starting materials were as follows: Cu, Fe, and Zn increased by factors of from two to four and Ca increased at least ten-fold in dry milled corn bran; Ca increased and phytate decreased in wheat brans; Zn increased and Fe decreased in soy hulls. These studies show that indigestible remnants of wheat brans in the human colon associate preferentially with calcium and that dry milled corn bran remnants can be loaded with increased concentrations of all four minerals, and especially with calcium. Concentrations of minerals and phytate were significantly greater in whole fecal samples from wheat bran diets than in the corresponding retrieved bran remnants.

Adult↗
PubMed1985

Effect of food supplementation (WIC) during pregnancy on birth weight.

Of 824 women screened, 410 were enrolled at midpregnancy in a prospective, randomized, controlled nutrition intervention study. Of these, 226 were predicted as likely to have small or large babies, 184 to have average-sized babies. Two hundred thirty eight mothers received USDA Women, Infants and Children (WIC) Food Supplementation vouchers from midpregnancy, 172 did not. Leukocyte protein synthesis (as a cell model) was significantly higher (p = 0.009) by 36 weeks gestation in supplemented mothers. Mean birth weight of their babies was greater, 3254 vs 3163 g, (+91 g) p = 0.039, adjusted for sex, gestational age, prenatal visits, pregnancy interval, smoking, and previous low birth weight infants. Controlling for entry weight obviated the significance of the difference, except for WIC supplemented smokers (greater than 10 cigarettes/day) whose babies were significantly heavier by +168 g (p = 0.017) than those of unsupplemented smokers. WIC partially protects fetal growth in smokers.

Birth Weight↗
PubMed1984

Increased cholesterol in plasma in a young man during experimental copper depletion.

Signs of copper depletion were produced in a healthy man by an amount of dietary copper (0.83 mg/day) similar to that in some contemporary diets. Urinary and fecal loss of copper exceeded intake. Plasma copper, ceruloplasmin, and superoxide dismutase activity in erythrocytes decreased. Cholesterol in plasma increased, and hematologic indices were unchanged. Lipid metabolism may be a more sensitive index of copper nutriture than are changes in hematology. The findings support the hypothesis that inadequate copper nutriture or altered copper metabolism contributes to the occurrence of ischemic heart disease.

Adult↗
PubMed1984

Alterations in the postnatal development of the cerebellar cortex due to zinc deficiency. II. Impaired maturation of Purkinje cells.

Zinc deficiency during the first 3 postnatal weeks retarded the maturation of Purkinje cells. The dendrites of the Purkinje cells of 21-day-old zinc-deficient (ZD) rats were reduced in size and had fewer branches. Somatic processes were found in 24% of the Purkinje cells of ZD animals. Only 3% of the Purkinje cells of normal animals had somatic processes. A basal polysomal mass in the Purkinje cells of 21-day-old ZD rats indicated that zinc deficiency impaired the cytoplasmic maturation of Purkinje cells. The development of the glial envestment of the dendrites and the maturation of climbing fibers also were retarded. Pair-fed controls were studied to control for the effects of inanition in the ZD dams. In the pups of pair-fed dams, undernutrition slightly impaired the growth of the dendrites but produced few qualitative changes in the maturation of the soma and climbing fibers. Somatic processes were found on 10% of the Purkinje cells of pair-fed animals. Thus, the findings in the ZD animals were not only caused by the decreased maternal food consumption but by zinc deficiency. The retarded maturation of Purkinje cells was related to the altered metabolism of Purkinje cells and to effects secondary to decreased numbers of parallel fibers.

Aging↗
PubMed1984

Alterations in the postnatal development of the cerebellar cortex due to zinc deficiency. III. Impaired dendritic differentiation of basket and stellate cells.

The effects of zinc deficiency and undernutrition on the dendritic differentiation of basket and stellate cells were studied in 21-day-old rats. A morphometric analysis of the dendritic branching of basket and stellate neurons was used that took into account the cell's position in the molecular layer. Zinc deficiency and undernutrition during the suckling period impaired the dendritic differentiation of cerebellar basket and stellate cells. The effects of zinc deficiency were not due totally to the reduced food intake of lactating dams. In the lower 65-75% of the molecular layer of zinc-deficient (ZD) pups, the dendritic field area, the total dendritic length and the number of branches per interneuron were reduced by 45-61%. In the lower 50-60% of the molecular layer, undernutrition reduced the dendritic field area, the total dendritic length and the number of branches per neuron by 32-44%. A comparison of ZD and undernourished (pair-fed) pups indicated that the dendritic field area and total dendritic length of neurons of ZD animals were 43% and 30% smaller in the lower half of the molecular layer. The number of branches per neuron was not significantly different between ZD and undernourished animals. The area of the soma was unaffected by dietary treatment. A delay in the onset of dendritic differentiation and a retarded rate of dendritic growth were considered possible mechanisms for the impaired dendritic differentiation.

Aging↗
PubMed1984

Iron status and brain function: serum ferritin levels associated with asymmetries of cortical electrophysiology and cognitive performance.

Levels of serum ferritin and iron were examined in relation to cognitive performance and quantitative EEG measures in 69 normal university students. Higher levels of serum ferritin were associated with greater activation of the left hemisphere relative to the right, indicated by less power in the EEG spectra from left hemisphere electrodes. Iron status was significantly related to cognitive performance on two of the cognitive tasks, and these relationships were consistent with the EEG asymmetries: higher ferritin predicted greater verbal fluency but poorer nonverbal auditory task performance. These results suggest that body iron stores are relevant to specific neurophysiological processes supporting attention.

Cognition↗
PubMed1984

Effect of consuming fiber from corn bran, soy hulls, or apple powder on glucose tolerance and plasma lipids in type II diabetes.

The effects of consuming corn bran, soy hulls, or apple powder on glucose and lipid metabolism were investigated in two studies of persons with type II diabetes. Fiber sources, completely or partially added to bread, were incorporated into subjects' self-selected diets. Low fiber white bread served as a control. In study A, 10 subjects consumed 26 g fiber source daily; in study B, eight subjects consumed 52 g fiber source. Biochemical tests, including a 2-h postprandial glucose test using a low fiber formula meal, were scheduled after 2 and 4 wk of each dietary treatment. Soy hull consumption slightly improved some measures of glucose tolerance, with results varying between the studies. Consumption of 52 g corn bran decreased very low-density lipoprotein cholesterol, triglycerides, and glycosylated Hb, but subject tolerance was poor with the particle size used. Consumption of 52 g apple powder increased low-density lipoprotein and total cholesterol levels.

Aged↗
PubMed1984

Influence of type and amount of dietary lipid on plasma lipid concentrations in endurance athletes.

Changes in plasma total cholesterol, triglyceride, and lipoprotein concentrations were assessed in three male endurance cyclists who consumed isoenergetic diets for 28-day periods in which carbohydrate, polyunsaturated fat, or saturated fat contributed about 50% of the daily energy intake. Dietary cholesterol was similar among the diets. Maximal aerobic capacity was maintained at 62 ml O2/(kg X min). Body weights were held within 3% of admission levels. The polyunsaturated fat diet significantly (p less than 0.05) reduced mean fasting plasma total cholesterol in comparison to the saturated fat and carbohydrate diets (160 versus 254 and 243 mg/dl, respectively). Similarly, the polyunsaturated fat diet depressed (p less than 0.05) mean plasma triglycerides relative to the saturated fat and carbohydrate diets (37 versus 62 and 79 mg/dl, respectively). No significant dietary effects were seen on high-density lipoprotein cholesterol. The observed changes in plasma total cholesterol were not significantly different than the values predicted by the Keys' equation, delta CHL = 1.35(2 delta S-delta P) + 1.5 delta Z. We conclude that under controlled conditions in which physical activity is constant l) dietary lipid differences influence fasting serum lipid and lipoprotein concentrations among men with high energy expenditures, and 2) the Keys' equation gives useful predictions of changes in plasma total cholesterol among vigorous men consuming different types and amounts of dietary lipid.

Adult↗
PubMed1984

Effect of oral folic acid supplements on zinc, copper, and iron absorption and excretion.

Effects of folic acid supplements on zinc excretion patterns were seen during studies of mild zinc deficiency in men. During these studies eight men were fed diets containing 150 micrograms of folacin (by analysis) per day. Four of the men were supplemented with 400 micrograms of pteroylglutamic acid (folic acid) every other day. All of the men were fed diets containing about 3.5 mg/Zn per day which were supplemented with 4.0 mg/Zn day for 4 wk and unsupplemented for 16 wk, then supplemented with 30.0 mg/Zn day for 4 wk. Their body weights were kept constant by adjustments of energy intakes and expenditures. Duplicate diets, stools, and urines were analyzed for zinc, copper, and iron. Fecal zinc was significantly (p less than 0.001) higher in the group that received folic acid supplements during the initial control and low zinc intake periods. No significant differences were seen during the period of high zinc intake. During all dietary periods urinary zinc excretion was reduced by about 50% by folic acid supplementation. No apparent changes occurred in iron or copper excretion. These data indicate that supplemental folate influences zinc homeostasis, perhaps through formation of an insoluble chelate and impairment of absorption.

Adult↗
PubMed1984

President's address.

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Nutritional Sciences↗