Morphological changes in human scalp hair roots during deprivation of protein.

Human subjects were deprived of protein for 15 days, after which time hair from the scalp of each subject was plucked and examined. Both the bulb and the external root sheath showed morphological changes. This technique may therefore be useful in diagnosing proteincalorie malnutrition.

Behavioral responses to artificial food colors.

Twenty-two young children, maintained on a diet that excluded certain foods, were challenged intermittently with a blend of seven artificial colors in a double-blind trial. Parents' observations provided the criteria of response. One child that responded mildly to the challenge and one that responded dramatically were detected. The latter, a 34-month-old female, showed a significant increase in aversive behaviors. These results further confirm previous controlled studies.

Wine versus ethanol in human nutrition. I. Nitrogen and calorie balance.

There are implications in the literature that wine is different from other alcoholic beverages and that it may even have a beneficial effect on the nutritional process. A metabolic study was undertaken in an attempt to document the effects of wine versus ethanol on absorption of various nutrients. Nitrogen and caloric data are presented here. During each of four 18-day experimental periods, six healthy, young men were given, in random order, a liter per day of the following test beverages: Zinfandel wine (9.3% w/v alcohol); dealcoholized Zinfandel wine; pure ethanol (9.3% w/v aqueous alcohol solution); and deionized water. These beverages were divided into four equal feedings and administered with a carefully controlled isocaloric diet over a 12-hr period. The subjects tended to lose weight on alcohol-containing regimens, suggesting that calories from alcohol may not be as efficient as those from fat and carbohydrate. Urinary excretion of nitrogen was significantly greater during wine and ethanol administration than during feeding of the other test beverages. This was reflected in an increase in uric acid and urea nitrogen output, primarily, the latter, suggesting that alcohol may directly affect protein catabolism. There was no significant difference in fecal nitrogen excretion between experimental periods.

Effect of oral contraceptive agents on the metabolism of some trace minerals.

Biochemical and metabolic alterations noted in women taking the oral contraceptive agents have included changes in blood levels of some trace minerals. Only a few of these, namely, iron, copper and zinc, have been studied. This paper intends to review the changes reported and outline the beginning of a series of studies to attempt to determine whether there is any metabolic significance to these alterations. The alterations reported in blood levels are generally believed to be related in large measure to alterations in levels of specific "transport" proteins induced primarily by estrogen. The significance of these changes is generally unknown, however, they involve slight elevations in serum iron and copper and possibly a reduction in serum zinc, although these are not as clear-cut as those of the other two trace minerals. In an attempt to determine whether any metabolic significance could be attributed to these changes, several studies have been instituted. The first, reported in this paper, consisted of a metabolic study on a group of seven women aged 18-32 who had been taking oral contraceptives for at least 3 years. The subjects were studied over four metabolic periods for a total length of 116 days. They were studied in a random fashion, generally 2 months on and 2 months off the pill, although this varied slightly. The subjects were fed a controlled formula diet throughout this study and vitamins and trace minerals, other than copper, iron and zinc, were given orally in capsules. A trace mineral solution was administered so that the total daily iron, copper and zinc could be fed in four equal feedings per day with the formula. Measurements consisted of studies of the blood levels of the trace minerals as well as their binding proteins, various indices of blood chemistry to assess health, hematological indices and total balance studies for each of the trace minerals and nitrogen. The balance studies included not only urine and fecal loss but also skin, menstrual and hair losers. Preliminary results are discussed as well as the formidable problems involved in trace mineral studies in humans. These problems are not only related to contamination but also are analytic in nature.

Wine versus ethanol in human nutrition. II. Fluid, sodium, and potassium balance.

Six healthy males were studied under metabolic unit conditions to determine the effects of wine vs ethanol on the absorption of various elements. Fluid, sodium, and potassium data are reported here. The following test beverages in the amount of 1 liter/day were administered in random order to each of the subjects during four 18-day experimental periods: Zinfandel wine (9.3% w/v alcohol); dealcoholized Zinfandel wine; pure ethanol (9.3% w/v aqueous alcohol solution); and deionized water. A strictly controlled isocaloric formula diet was given with the test beverage in four equal feedings over a 12-hr period. No diuretic effect of alcohol was detected in any of the subjects. Urinary sodium was significantly less during the dealcoholized wine period than during the ethanol and water periods. Urinary potassium was significantly greater during ethanol administration as compared with the other test beverages. Fecal and serum sodium and potassium were essentially unchanged throughout the study.

Wine versus ethanol in human nutrition. III. Calcium, phosphorous, and magnesium balance.

A metabolic balance study was performed to determine the effects of wine vs ethanol on absorption of various elements. Calcium, phosphorus, and magnesium data are reported here. The study was divided into four 18-day experimental periods during which six healthy males were given, in random order, 1 liter/day of one of the following test beverages: Zinfandel wine (9.3% w/v alcohol); delacholized Zinfandel wine; pure ethanol (9.3% w/v aqueous solution); or deionized water. The test beverages were administered along with a controlled isocaloric diet in four equal feedings over a 12-hr period. Each man served as his own control. Urinary calcium and magnesium did not change appreciably during the course of the study. Urinary phosphorous, however, was significantly greater during wine and ethanol administration, suggesting that alcohol may affect the metabolism or renal tubular reabsorption of this element. Despite considerable individual variation, the data showed that wine and dealcoholized wine enhanced absorption of calcium, phosphorus, and magnesium. This apparently was due to an effect of one or more of the many congeners present in wine and absent in a calorically equivalent amount of pure ethanol. The natural acidity of wine also may have played a role in creating a more favorable intraluminal environment for absorption. There was no significant difference between experimental periods in serum calcium, phosphorus, and magnesium.

Autoregulatory homestatic nature of energy balance.

This paper proposes a new theory regarding energy regulation in man. Current theory states that similar adults have similar energy requirements when engaged in similar activities. As a corollary, if activities remain constant and energy intake is altered, weight will change. This theory has been unable to explain the repeated observations that individuals of the same sex and age and engaged in similar work show a mean weekly coefficient of variation in energy intake of about 16% without significant fluctuations in body weight. Furthermore, repeated studies have failed to show any individual "pattern" relating energy intake to output. This lack of pattern has been attributed either to methodological error or to the fact that human energy requirements cannot be determined by current methods. This paper shows that neither case is correct. The explanation lies in the stochastic stationary nature of energy requirements. Because of the nature of significant intraindividual variations noted in all experiments, "requirement" is a dynamic concept, and energy balance will vary as a matter of course about zero. The implications of this for the individual, society, and policy are enormous and are discussed herein.

Zinc, copper, and iron balance in elderly men.

Two-3-wk balance studies for zinc, copper, and iron were carried out in six elderly male subjects who were confined to a metabolic unit for a long-term study (12 wk) with constant dietary mineral intake. Average zinc balance was 0.1 +/- 0.05 (mean +/- SEM) and serum zinc increased in all subjects during the course of the study. Average copper balance was 0.06 +/- 0.06 (mean +/- SEM). There was no significant change in serum copper ceruloplasmin, but all were within normal ranges except for elevated serum copper in one subject who appeared to be in negative copper balance. Iron balance appeared to be negative, -0.44 +/- 0.16 (mean +/- SEM), despite improved blood iron parameters in five of six subjects. Results of this long-term balance study suggests that current dietary recommendations of 15 mg of zinc and 2 to 3 mg of copper are adequate for elderly as well as younger adults. However, balance data for individuals must be interpreted with caution, should be used only with other parameters, and should not be relied on exclusively as a basis for dietary recommendations. Additional data are needed to evaluate dietary iron recommendations for elderly men.

Wine versus ethanol in human nutrition. IV. Zinc balance.

Six healthy young men participated in a metabolic balance study to assess the effects of wine versus ethanol on absorption of various elements. Zinc data are reported here. During each of four 18-day experimental periods, the subjects were fed a controlled diet plus 1 liter/day of one of the following test beverages, administered in random order: Zinfandel wine, dealcoholized Zinfandel wine, an aqueous ethanol solution, or deionized water. Urinary zinc was significantly greater during wine and ethanol administration than during administration of the nonalcoholic beverages, suggesting that alcohol may affect the metabolism or renal conservation mechanism for zinc. The possibility of muscle catabolism due to alcohol ingestion is discussed. There was increased absorption and, perhaps, also, decreased endogenous secretion of zinc during the wine and dealcoholized wine periods, as compared with ethanol and deionized water. That presumably was due to the nonalcoholic constiuents of wine. Analysis of zinc in whole sweat after strenous exercise revealed that a considerable amount of this ion can be lost under conditions of excessive sweating.

Incidence and duration of breast-feeding in a health maintenance organization population.

A breast-feeding incidence and duration study in a heterogeneous population confirmed the increased incidence of breast-feeding reported among American women. Of 632 women delivering between May and August of 1980, 66% chose to breast-feed, a decision determined to be significantly related to race, age, marital status, and parity. Cesarean deliveries discouraged breast-feeding, whereas nursing immediately after delivery and keeping the infant in the room during the hospital stay encouraged breast-feeding. Of 417 women who were breast-feeding, 58% had stopped by four months postpartum, a decision found to be related significantly to race, age, and receiving formula in the hospital. Formula supplementation in the hospital was associated with a shorter breast-feeding period. The most rapid decline in breast-feeding occurred in the first two weeks postpartum. Because this is the period in which women are most likely to discontinue breast-feeding, it could be a productive target period for support and assistance by health professionals.

Studies in calcium metabolism. II. Effects of low calcium and variable protein intake on human calcium metabolism.

Six healthy males consumed diets containing about 0.1 g calcium/day at three levels of protein intake: 0.9, 12, and 24 g nitrogen/day. Daily urinary calcium excretion on the 0.9 nitrogen diet was 51 mg, 99 mg on the 12 g nitrogen diet, and 161 mg on the 24 g nitrogen diet. A calcium supplement of 0.9 g for four subjects on the 12 g nitrogen diet caused an increase in urinary calcium from 68 to 160 mg/day. Varying the calcium and protein intake had no effect on dermal calcium loss or serum calcium. Five subjects had the least negative calcium balance on the 12 g nitrogen diet. Increase in urinary calcium is not likely to result solely from enhancement of intestinal calcium absorption. Our data suggest that increased glomerular filtration with possible inhibition of renal tubular reabsorption of calcium may be an additional mechanism responsible for the calciuretic effect during high-protein intake.

Protein-induced hypercalciuria: a longer term study.

Urine calcium excretion is known to be directly correlated with the level of dietary protein intake. In this experiment we examined the persistence of the hypercalciuria induced by the consumption of high protein diets, and the mechanism of the calciuric response. In a 95-day metabolic study, each of six adult male subjects received formula diets supplying 12 g nitrogen or 36 g nitrogen, and approximately 1400 mg calcium per day. Urine calcium increased rapidly and significantly from an average of 191 mg/day on the 12 g nitrogen diet to 277 mg/day on the 36 g nitrogen diet. There was no significant difference in the apparent absorption of calcium, so that overall calcium balance was -37 mg/day on the 12 g nitrogen diet, and significantly lower at -137 mg/day in subjects consuming the high protein diet. Levels of urinary hydroxyproline, serum insulin, and parathyroid hormone were not significantly increased by high intakes of protein. A decrease in the fractional reabsorption of calcium by the kidney seems to be the most likely cause of the protein-induced hypercalciuria. The consumption of high calcium diets is unlikely to prevent the negative calcium balance and probable bone loss induced by the consumption of high protein diets.

Lactation and pregnancy in Iran. III. Hormonal factors.

Lactation failure is common in urban areas of industrially developing countries, but little is known about its epidemiology and causality. The study reported here was undertaken to investigate the serum levels of some hormones other than prolactin that have been shown in animal studies to play a role in lactation, and to examine their relationship to adequacy of lactation and to nutritional and socioeconomic status in urban Iranian women. Serum levels of placental lactogen, growth hormone, cortisol, and thyroid hormones were measured under standard conditions in two groups of pregnant women from low and low middle socioeconomic areas of Teheran, 1 or 2 weeks before parturition and the latter three hormones again in the 3rd month postpartum. Significant differences were found in the biochemical parameters between socioeconomic groups. Hemoglobin and serum albumin values were lower and all the globulin fractions (except alpha 2 globulin during pregnancy), growth hormone and cortisol were higher in the low than the middle socioeconomic subjects, both during pregnancy and postpartum. The discrepancies between the socioeconomic groups were greater postpartum. Growth hormone level was significantly lower in subjects with adequate lactation than inadequate or ceased, and cortisol values show the same trend. No correlations were found between the measured parameters of nutritional status nor free thyroxine values and lactation adequacy. In view of the role of growth hormone and cortisol in stress and malnutrition and some evidence of a reciprocal relationship between growth hormone and prolactin, these hormones may be a link in the chain between the urban environment, malnutrition and lactation failure.

Lactation and pregnancy in Iran. I. Social and economic aspects.

Adequacy of lactation was assessed in Teheran women of low (LSE) and lower-middle (MSE) socioeconomic status in the third month postpartum, as part of a study linking nutrition, hormonal status, and lactation. Methods of assessment of nutritional adequacy are discussed. Characteristics of the socioeconomic groups, infant mortality, food beliefs related to lactation, and supplemental feeding practices are described. Of the LSE mothers 15 to 30% and of the MSE mothers 40 to 55% had a fully adequate milk supply in the third month. Substitutes used and affordable by the LSE were nutritionally inadequate. LSE mothers were traditional in their food beliefs. MSE mothers demonstrate the influence of scientific nutrition knowledge. The low percentage of lactation adequacy even in the MSE indicates that other social or health factors associated with urban living conditions may be just as important as economic and nutritional factors in lactation failure.

PIP: Adequacy of lactation was assessed in Teheran, Iran, among women of low (LSE) and lower-middle (MSE) socioeconomic status in the 3rd month postpartum as part of a study linking nutrition, hormonal status, and lactation. Subjects were selected randomly from women with uncomplicated pregnancies who attended 2 clinics in Teheran within 2 weeks of the expected date of birth. Subjects were interviewed, anthropometric data were obtained, and a blood sample was taken for hormonal and nutritional evaluation. Socioeconomic data, medical history, and dietary intake information were obtained. Characteristics of the socioeconomic groups, infant mortality, food beliefs related to lactation, and supplemental feeding practices are described. The criteria of lactation adequacy used were based primarily on the classification of nutritional status in early childhood as proposed by McLaren and Read. 15-30% of the LSE and 40-55% of the MSE mothers had a fully adequate milk supply in the 3rd month. Substitutes used and affordable by the LSE mothers were nutritionally inadequate, and this group of mothers was traditional in their food beliefs. MSE mothers demonstrated the influence of scientific knowledge. The low percentage of lactation adequacy even among the MSE mothers indicates that other social or health factors associated with urban living conditions may be as important as economic and nutritional factors in lactation failure.

Lactation and pregnancy in Iran. II. Diet and nutritional status.

Dietary intake in the third month postpartum and nutritional status during pregnancy close to term were assessed in Iranian urban uomen of low and middle socioeconomic status as part of a study investigating nutrition, hormonal status, and lactation in a population where lactation failure is a serious problem. Dietary intake was assessed by the 24-hr-recall method. The greatest differential in food groups consumed was in animal products, fruit, and vegetables. Intake of nutrients equal to or less than 80% of recommendations in both socioeconomic groups were energy, vitamin B6, folacin, calcium, iron, and zinc. In the low socio-economic group, only average intakes of vitamin C, thiamin and protein met the standards. Significant differences were found between the socioeconomic groups in hemoglobin, hematocrit, serum total protein, and protein fractions, but not in weight and height. The only parameters of nutritional status significantly correlated with adequacy of lactation were postpartum weight and percent of standard weight for height in the low socioeconomic group, and hematocrit values in the middle socioeconomic group. Differences between pregnant and postpartum individual values of the blood parameters were in general greater in the middle socioeconomic group than the low socioeconomic group.

PIP: Dietary intake in the 3rd month postpartum and nutritional status during pregnancy close to term were assessed in Iranian urban women of (LSE) low socioeconomic status and (MSE) middle socioeconomic status as part of a study investigating nutrition, hormonal status, and lactation in a population where lactation failure is a serious problem. Dietary intake was assessed by the 24-hour recall method. The greatest differential in food groups consumed was in animal products, fruit, and vegetables. Intake of nutrients = or than 80% of that recommended to both socioeconomic groups were energy, vitamin B6, folacin, calcium, iron, and zinc. In the LSE group, only average intakes of vitamin C, thiamin, and protein met the standards. Significant differences were found between the socioeconomic groups in hemoglobin, hematocrit, serum total protein, and protein fractions, but not in weight and height. The only parameters of nutritional status significantly correlated with adequacy of lactation were postpartum weight and % of standard weight for height in the LSE group, and hematocrit values in the MSE group. Differences between pregnant and postpartum individual values of the blood parameters were in general greater in the MSE group than the LSE group.

Polyethylene glycol as a quantitative fecal marker in human nutrition experiments.

Data are summarized from five experiments in which polyethylene glycol (PEG) was fed to 51 subjects as a quantitative fecal marker. In three experiments PEG was fed continuously for 35 to 106 days. Preexperimental diet was assumed to have been completely excreted when the ratio of fecal PEG to fecal dry solids became constant. This took more than 7 days to occur in 50% of the subjects. Fecal recovery of PEG averaged only 93% of that consumed. PEG was a valid fecal marker for nitrogen, calcium, magnesium, iron, and zinc, but was less valid for sodium. In one experiment where PEG and chromic oxide (Cr2O3) were fed simultaneously, PEG was excreted faster on average than Cr2O3. In most subjects, small amounts of Cr2O3 were excreted sporadically for 42 days after Cr2O3 feeding had ceased. Inclusion of quantitative fecal markers permitted identification of the time when preexperimental diet had been completely eliminated, subjects who showed marked pooling of intestinal contents, and changes in the amount of fecal dry solids. However, an average fecal recovery of only 93% of the PEG or Cr2O3 consumed suggests that further work is needed before the recovery of either of these markers can be used with confidence for the correction of nutrient balance data.

Absorption of stable isotopes of iron, copper, and zinc during oral contraceptives use.

The absorption of iron, copper, and zinc was determined in 22 women 19 to 25 years of age from the difference between intake and fecal output of the stable isotopes 58Fe, 65Cu, and 70Zn, as measured by neutron activation analysis. Of the 22 women, 14 were using oral contraceptive agents, and the other eight were not. Absorption in the group using oral contraceptive agents did not differ significantly from the group not using oral contraceptive agents. The overall iron absorption averaged 14%, copper 57%, and zinc 38%.

PIP: Absorption of iron, copper, and zinc was determined in 22 women (19-25 years old) from the difference between intake (regulated by testers) and fecal output of the stable isotopes Fe-58, Cu-65, and Zn-70, as measured by neutron activation analysis. Of the 22, 14 were using oral contraceptives (OCs) (1 sequential and the rest combined), and 8 were not. Absorption values did not differ significantly between the OC users and the nonusers. These data suggest that stable isotopes of elements offer promise as a means of measuring mineral absorption without the undesirable aspects of feeding radioactive materials to humans. Disadvantages include difficulty obtaining hardward, expense of radioactive isotopes, and requirement for additional radiochemical separations for zinc, and possibly other minerals.

Iron stores in users of oral contraceptive agents.

A comparison of serum ferritin and other parameters of iron status was made between 46 women taking oral contraceptive agents (OCAs) for two or more years continuously and 71 women who never took OCAs. The mean serum ferritin level for the OCA users was 39.5 +/- 21.5 ng/ml and the control group mean level was 25.4 +/- 15.96 ng/ml, which is significantly different at p less than 0.001. Serum transferrin, serum iron, TIBC, MCH and MCHC levels were significantly greater for the OCA users group. Significantly lower RBC and hematocrit levels were found for OCA users while other parameters, hemoglobin, MCV and percent transferrin saturation, were not significantly different. No major differences in subject characteristics and dietary traits were evidenced, except a difference in reported menstrual cycle losses and a higher heme iron content in the diet of the OCA users.

PIP: A comparison of serum ferritin and other parameters of iron status was made between 46 women taking oral contraceptives (OCs) for 2 or more years continuously and 71 women who never took them. The mean serum ferritin level for OC users was 39.5 +or- 21.5 ng/ml and the control group mean level was 25.4 +or- 15.96 ng/ml which is significantly different at P0.001. Serum transferrin, serum iron, TIBC, MCH, and MCHC levels were significantly greater for the group using OCs. Significantly lower RBD and hematocrit levels were found for OC users while other parameters, hemoglobin, MCV, and percent transferrin saturation were not significantly different. No major differences in subject characteristics and dietary traits were in evidence, except for a difference in reported menstrual cycle losses and a higher heme iron content in the diet of OC users.

Integumentary loss of calcium.

Integumentary calcium loss was studied in 16 healthy young men. The daily loss by the 16 ambulatory but relatively sedentary young men in 52 determinations of 6-day periods each was 8.7 +/- 1.9 mg/m2 per day (average 15.8 mg/man per day). The amount lost was not influenced by calcium intake (0.1 to 2.3 g/day). In contrast to urinary calcium excretion, which is directly related to protein intake, there was no significant change in integumentary calcium loss with varying protein intakes (1 to 96 g nitrogen per day). No compensatory relationship between urinary and integumentary calcium excretion was noted. During strenuous exercise calcium loss increased to an average of 25 mg in 40 min. There was no compensatory decrease in urinary excretion on the day of strenuous exercise. It was also noted that integumentary calcium loss was not affected by general calcium balance.

Sulphate, acid-base, and mineral balances of obese women during weight loss.

Four obese women, each at least 50% above their expected weight for height were maintained in the metabolic unit for 63 days on liquid formula diets of differing protein and calorie content. We made the following findings: 1) When 12 g protein nitrogen was consumed, 1 mEq of acid was excreted in the urine for every 2 mEq of urinary sulphate. 2) On a protein-free diet more acid was excreted in the urine than could be accounted for by oxidation of sulphur to the sulphate which was excreted in the urine. 3) Both increased consumption of protein and a restriction of dietary calories was associated with an increase of urinary acid. 4) Urinary sulphur excretion was closely correlated with nitrogen intake and urinary urea nitrogen excretion. However, on a protein-free diet the ratio of total nitrogen to sulphur in the urine was greater than when 12 g protein nitrogen was consumed. 5) There is some evidence that when total calorie intake was reduced at a level of 12 g protein nitrogen intake, the ratio of urinary urea nitrogen to urinary sulfur decreased. This suggests selective retention of some nonsulphur containing amino acids and/or selective oxidation of sulphur-containing amino acids. 6) In general, urinary calcium and magnesium excretions were depressed both with a decrease in protein consumption and a decrease in caloric intake. 7) The urinary excretions of calcium and magnesium showed a tendency to fall during the 63 days of the experiment. 8) The urinary and fecal phosphorus excretion remained constant during the various metabolic periods of the experiment.