The effects of vitamin A-deficient diets containing lactose in producing bladder calculi and tumors in rats.

This report describes studies in which diets have been developed which when fed to rats commonly result in the formation of primary urinary bladder calculi. The bladder walls of most of these rats but not those without urinary stones were grossly hypertrophied. Microscopic examinations in one of the studies indicated that about a quarter of the bladders containing stones showed histological changes consistent with those characterized as grade I to II transitional cell carcinomas. In all cases animals showing these histological abnormalities consumed vitamin A-deficient diets in which the carbohydrate was supplied mostly by lactose.

Nutrition studies in Thailand: effects of calories, nutrient supplements, and health interventions on growth of preschool Thai village children.

A study of the effects of providing high-calorie and vitamin-mineral supplements to preschool village children retarded in growth and development in Chiang Mai, Thailand was done. The preschool children of 24 villages with a population of approximately 11,000 were divided into five control and intervention groups. The interventions consisted of a village health program, high-calorie snacks, and vitamin-mineral supplements. The supplements when used were provided in day care centers for preschool children. The health and nutrition interventions used did not significantly affect growth during the study period reported from December 1981 to October 1983. Monthly changes in length and weight observed in this and a previous study indicate that growth patterns in Thai children are different from those seen in industrialized societies. Factors other than lack of nutrients and infection may be responsible for the inadequate growth often reported in developing countries.

Aging and vitamin B-6 depletion: effects on plasma pyridoxal-5'-phosphate and erythrocyte aspartate aminotransferase activity coefficients in rats.

Plasma pyridoxal-5'-phosphate (PLP) and erythrocyte aspartate aminotransferase activity coefficients were longitudinally determined in rats. Blood was obtained at weeks 0, 1, 2, 4, 6, 9, and 11 from rats initially aged 3 wk, 3 mo, 12 mo, and 23 mo (weeks 0, 1, 4, 6, and 9 only). The diet groups were ad libitum control (ALC), deficient (DEF), and pair-fed control (PF). Plasma PLP concentrations of controls were highest at 3 mo, intermediate at 3 wk and 12 mo, and lowest at 23 mo. When an additional group of 22-mo-old rats was fed a high-vitamin B-6 diet for 4 wk, their low baseline plasma PLP concentrations did not increase significantly. Plasma PLP decreased significantly within 1 wk and activity coefficients increased significantly by week 4 in all DEF rats. Depletion was most rapid and severe in the youngest DEF rats and least in 12-mo-old DEF rats. Mechanisms for the low plasma PLP control values and resistance to depletion in aged rats remain to be determined.

Protein and amino acids of breast milk from Thai mothers.

The protein, amino acids, and nonprotein nitrogen of milk samples obtained from Thai mothers over a period of 0 to more than 270 days postpartum were determined. Protein levels decreased from 1.56% during the 1st wk to a low of about 0.6% from 180 to 270 days and then rose to about 0.7%. The amino acid pattern of the milks suggested a number of differences in their composition and those of samples analyzed in other countries. Nonprotein nitrogen varied from 20 to 40% of the total nitrogen of the milk. It has been concluded that the need for supplementation of breast-fed Thai babies may occur earlier than many nutritionists advocate.

PIP: This study evaluates the effects of prolonged lactation on the quantity of protein and pattern of amino acids in breast milk of 135 Thai women at various times of lactation (from 0 to 270 days postpartum). Breast milk samples were collected approximately 3 hours after nursing at various times during 1978. Total nitrogen, tryptophan and amino acids were respectively analyzed by the methods of Williams, Lorenzo-Andreu and Frandsen and Matheson, and Hitachi Perkin-Elmer Model KLA3B amino acid analyzer. Protein level in breast milk was highest during the 1st week (1.56%) and decreased steadily with time until a level of 0.60% during the period of 180 to 270 days, after which protein content appeared to increase. Ratio of essential to nonessential amino acids was constant throughout the study. Protein or amino acid levels during lactation were not significantly affected by maternal age and parity, although maternal age, parity and socioeconomic factors had been known to affect total milk secretion. Amino acid levels in this study were generally similar to reported values from American and Scottish women, although methionine, valine and tyrosine were lower and tryptophan and lysine were higher. Although breast milk has a nutritional value of the highest quality, it can be argued that the need for supplemental feeding may still occur earlier in life than is often realized. A discussion of the FAO/WHO standards for protein allowances suggests that infants up to 3 months of age require approximately 2 or more g of milk protein per kg daily, while children 60 to 12 months of age require about 1.5 g/kg/daily. Considering that protein content of Thai breast milk is about 0.9% after 3 months of lactation, it is estimated that 1250 ml of milk are needed to supply the protein needs of a 3-month old child, and 950 ml would be insufficient (average daily production of milk varies from 850 ml to 1200 ml). Many Thai and other women who are exclusively breastfeeding may find it difficult to provide the protein needs of their infants, unless supplemental feeding is carried out.

Studies of the elderly in Boston. I. The effects of iron fortification on moderately anemic peole.

It has been reported that large numbers of elderly Americans are moderately anemic because of iron deficiency anemia. In the present study, information has been obtained concerning blood composition, health, and nutritional habits of 779 people over 60 years of age, institutionalized or free-living in the Boston area. This paper presents the results of their blood examinations. Two hundred twenty-one of the free-living people examined who showed hemoglobin levels between 9 and 12.9 g/dl agreed to participate in an iron fortification study. Two-thirds of them received iron-fortified grain products daily for 6 to 8 months. The rest received the same foods without added iron. At the end of the experimental period a marked increase in hemoglobin levels averaging 1.4 g/dl was observed in both groups. This appeared to be attributable to an undefined intervention effect; no measurable effects attributable to the iron fortification were observed. Three months of daily ferrous sulfate administration to those whose hemoglobin levels remained below 13 g/dl was without effect. Examination of the data obtained suggests that the cause of the moderately low hemoglobin levels initially observed was not occult bleeding or folic acid or iron deficiency.

The relationship between estrogen levels and diets of Caucasian American and Oriental immigrant women.

The relationship between diet and estrogens was studied in two groups of women with different dietary habits and breast cancer risks. Plasma estrogens and androgens and 24-h urinary and fecal excretion of estrogens were measured in premenopausal and postmenopausal Caucasians and recent Oriental immigrants from Southeast Asia to Hawaii. Premenopausal Caucasians had 30-75% higher plasma estrone and estradiol levels than their age-matched cohorts in Hawaii, and the postmenopausal Caucasians had 3-fold higher plasma levels of estradiol. The Oriental women excreted more than twice the amount of estrogen in their feces but they excreted significantly less in their urine. Thus, the ratio of urinary-to-fecal excretion was approximately 3-5 times higher in young Caucasian women. Analysis of dietary components and plasma estrogens in premenopausal women showed a positive correlation between daily intake of total fat and saturated fat and plasma estrone and estradiol concentrations.

Prevalence of riboflavin deficiency among Guatemalan elderly people and its relationship to milk intake.

Six groups of elderly subjects from central Guatemala were assessed for riboflavin status by using the erythrocyte glutathione reductase activity coefficient (EGRAC). The prevalence of riboflavin deficiency ranged from 50% to 76% among the free-living rural elderly subjects. Milk intake data that were collected from some of the subjects showed a significant correlation (P < 0.0001) between frequency of milk intake and riboflavin status. In a short-term riboflavin supplementation experiment in which nine riboflavin-deficient subjects were given 10 mg riboflavin/d for 3 d, all the subjects' EGRACs were normalized by the supplementation. However, they returned to a state of deficiency within 2 wk while consuming their usual diets without supplementation. It appears that the high prevalence of riboflavin deficiency in elderly Guatemalan people is caused by inadequate intake of riboflavin-rich foods such as dairy products, and that sufficient amounts of riboflavin need to be ingested regularly to maintain satisfactory riboflavin status.

Evaluation of the impact of weaning food messages on infant feeding practices and child growth in rural Bangladesh.

In rural Bangladesh, a community-based weaning intervention used volunteers to teach complementary feeding to families of 62 breast-fed infants aged 6-12 mo. Over 5 mo, treatment children gained on average 0.46 SD (approximately 460 g) more in weight-for-age (WAZ) than the 55 control subjects, and were approximately 0.5 kg heavier at the final measure. The differences were statistically significant (P < 0.001). The percent median weight-for-age (WAPM) of treatment children held steady at 76% of the National Center for Health Statistics' reference, whereas the WAPM of control subjects dropped from 78% to 72%. The increase in percentage points of severe malnutrition (below -3 WAZ) was only 5% in the treatment group compared with 26% in the control subjects. Treatment children consumed a significantly greater percent of their energy and protein requirements from complementary foods than did control subjects. The affordable complementary foods consisted mainly of cereal porridge with oil and brown sugar. These findings suggest that educational interventions teaching families to feed hygienic, simple, cheap, energy-enriched complementary foods to breast-fed infants after 5-6 mo can improve child growth, even under impoverished conditions.

Vitamin B-6 deficiency impairs interleukin 2 production and lymphocyte proliferation in elderly adults.

The effect of vitamin B-6 deficiency on immune response was studied in eight healthy elderly adults. The protocol consisted of a 5-d baseline (BL) period; a vitamin B-6-depletion period of less than or equal to 20 d; three stages of vitamin B-6-repletion, each lasting 21 d; and a 4-d final phase. The amounts of vitamin B-6 ingested during the different phases of the study were 3.00, 15.00, 22.50, and 33.75 micrograms.kg body wt-1.d-1, respectively. During the final phase the subjects ingested 50 mg vitamin B-6/d. Fasting blood was collected at the end of each period. Vitamin B-6 depletion significantly decreased percentage and total number of lymphocytes, mitogenic responses of peripheral blood lymphocytes to T- and B-cell mitogens, and interleukin 2 production. These indices returned to BL values after the third vitamin B-6-repletion period, when the total vitamin B-6 intakes were 1.90 +/- 0.18 mg/d for women and 2.88 +/- 0.17 mg/d for men. Vitamin B-6 deficiency impairs in vitro indices of cell-mediated immunity in healthy elderly adults. This impairment is reversible by vitamin B-6 repletion.

Effect of vitamin B-6 deficiency on fasting plasma homocysteine concentrations.

The catabolism of homocysteine through cystathionine synthesis requires pyridoxal-5'-phosphate, thus the effect of vitamin B-6 deficiency on plasma homocysteine concentrations was evaluated. Total fasting plasma homocysteine concentrations were measured in 11 elderly subjects aged 64.4 +/- 1.7 y (mean +/- SE) who consumed a vitamin B-6-deficient diet for less than or equal to 20 d. Only 1 of the 11 subjects was found to have elevated homocysteine concentrations even though all subjects exhibited high urinary xanthurenic acid concentrations after a tryptophan load, a measure indicative of vitamin B-6 deficiency. In a supporting study, fasting plasma homocysteine concentrations were measured in 3- and 23-mo-old rats fed vitamin B-6-deficient diets and were compared with those of vitamin B-6-replete, pair-fed controls. There was no difference in homocysteine concentrations between deficient and pair-fed animals after 6 wk of the dietary regimen for either age group; after 9 wk a modest elevation was observed in the 3-mo-old deficient rats whereas no difference was observed for the 23-mo-old rats. It is concluded that fasting plasma homocysteine concentrations are not initially elevated in vitamin B-6 deficiency and therefore fasting plasma homocysteine concentrations are not a good indicator of vitamin B-6 status.

Vitamin C (ascorbic acid): new roles, new requirements?

There is an enormous amount of literature on vitamin C intake and health in animals, cell cultures, and humans. Beyond its function in collagen formation, ascorbic acid is known to increase absorption of inorganic iron, to have essential roles in the metabolism of folic acid and of some amino acids and hormones, and to act as an antioxidant. In recent years, research has increasingly focused on this latter function, stimulated by suggestions that "oxidative stress" may be a causal factor in the etiology of such diverse and important disorders of aging as cancer, cardiovascular disease, and cataract formation. The present evidence is strong enough to have convinced nutritionists that daily vitamin C intake should be many times higher than the amount needed to protect against scurvy, and this is reflected in the present Recommended Dietary Allowances. Suggestions that the recommended levels should be higher still are largely based on extrapolations from results of animal and tissue culture studies. How much ascorbic acid is necessary to achieve in humans the effects seen in animal studies is not clear. In general, the limited human studies have not been persuasive. The data are incomplete, and many of the studies have serious flaws. There are no toxicity studies of the type done for new compounds being considered for approval as therapy for major disease conditions. Intervention studies will be difficult, but are essential, and methods for tissue saturation measurement must be defined before new recommendations for the public are designed.

Nutrition evaluation of dietary fat substitutes.

In response to US dietary guidelines and health goals, the food industry has introduced a variety of innovative food products designed to help the American public lower its fat intake. The physical characteristics and safety considerations of these products are reviewed, as well as their association with chronic disease prevention.

Science--neglected ingredient of nutrition policy. 10th Martha F. Trulson Memorial Lecture.

Programs to alleviate malnutrition in children in developing countries need revision. Intervention field trials in Thailand, Tunisia, and Guatemala, based on amino acid fortification and supplementary vitamins and minerals, have had little effect on children. In fact, it is often a misconception that frank deficiencies are common characteristics of malnutrition in developing countries.Rather, stunted growth--caused by caloric deficiency often in the presence of adequate food supplies--may be the most prevalent form of malnutrition. The situation occurs when the customary staple food--for instance, rice in Thailand--has such a high caloric density that children cannot eat enough food to meet their needs. Knowledge is not vet available on ways to solve this dilemma. Nevertheless nutritionists must come forward and be willing to contribute their knowledge and expertise in the shaping of national and international nutrition policies to improve the healthand well-being of populations.

Nutrition and behavioral characteristics and determinants of plasma cholesterol levels in men and women.

The National Cholesterol Education Program advocates dietary interventions in persons with high and moderate blood cholesterol levels and in the general population as a preventive measure for coronary heart disease. For these efforts to be successful, it is necessary to understand consumer characteristics and behaviors, including nutrient intake and dietary patterns. We studied the relationship of plasma cholesterol levels to consumer characteristics and dietary behaviors by examining 127 men (aged 20 through 71 years) and 187 women (aged 18 through 67 years) as part of a cholesterol screening project in the administrative offices and academic departments of Boston University from March 1988 through June 1988. Our results showed that specific consumer characteristics and dietary behaviors significantly differentiated male and female groups with low, moderate, and high cholesterol levels. Factors that should be considered in planning dietary interventions aimed at cholesterol reduction in men include spouse involvement and support in lipid-lowering interventions; weight reduction; increase in exercise; reduction in beef intake; and increases in dietary fiber and carbohydrates, particularly fruits. For women, recommendations include weight reduction; possible interventions aimed at reducing blood pressure (ie, behavioral modification aimed at reducing stress, increasing exercise, and cooking low-salt meals); reduction in beef intake, dietary fat, and saturated fat; and increases in carbohydrates and dietary fiber.

A longitudinal study of the impact of behavioural change intervention on cleanliness, diarrhoeal morbidity and growth of children in rural Bangladesh.

A community-based intervention was developed through direct participation of the target population in assessment and iterative trials to improve hygiene practices and to reduce childhood diarrhoea in lowland rural Bangladesh. A total of 185 (98%) households with children ages 0-18 months in five contiguous villages were targeted for the interventions. A comparison site was selected for a detailed observational study and for use as a control for the intervention. About 97% of all households with children ages 0-18 months were enrolled for study at the control site. Children in this age group were targeted because at this developmental stage they were most vulnerable to diarrhoeal morbidity and malnutrition (related to unhygienic practices). The intervention was implemented with the assistance of village leaders through a "Clean Life" campaign by local project workers and volunteer mothers who were chosen from the target households. The intervention activities started in January 1986 and lasted for 7 months. Higher adoption rates of the intervention were associated with better cleanliness status, which was related to lower diarrhoea and malnutrition rates in the intervention site. The results of between-site longitudinal analyses showed that after the intervention, the intervention site had substantially higher cleanliness scores, lower diarrhoeal morbidity, and better growth status compared to those of the control site, with differences increasing over time. The findings suggest that this type of community-based intervention can be very beneficial in modifying hygiene behaviours and lowering childhood diarrhoea and malnutrition.

Maternal education and child feeding practices in rural Bangladesh.

This study in rural lowland Bangladesh used spot and event observations from 185 children aged 4-27 months in order to examine whether child feeding practices differed with mother's education and with household education. Each child and his/her caretakers were observed for a mean of 20 hr over 6 months from February to July 1986. Only 25% of mothers and 51% of fathers had had any formal education. Exploratory partial correlations and stepwise multiple regression analyses revealed significant behavioral differences with both maternal and household measures of education while controlling for wealth. Caretakers in families with education were found to feed the children more frequently, with fresher food, and in cleaner, more protected places. They did not allow their children to eat food intended for someone else as often, and were more observant when their children's food dropped during the feeding. These caretakers also used more cups and bottles for feedings, breastfed their children less frequently, and their mothers terminated the breastfeedings more often. These behaviors suggested a shift from less attentive feeding practices and less frequent feedings to more frequent feedings in which the caretaker took more control of the child's feeding sessions. They also suggest a commitment to more labor-intensive child care. These associations between education and child feeding practices are mechanisms through which maternal education may improve child health and growth. They suggest the need for promoting more formal and nonformal education.

The paradox of hunger and economic prosperity in America.

Within a period of twenty years, America discovered that many of its citizens were hungry, acted to greatly reduce this problem through an array of federal programs, and, in the 1980s, learned that hunger has reappeared in epidemic proportions. The return of hunger to the U.S. is associated with economic and tax policies that have reallocated income distribution from poor and middle-income groups to the wealthy, and with a corresponding failure to utilize the federal government to protect high-risk population groups from undernutrition associated with growing economic deprivation in the nation.

The politics of hunger: when science and ideology clash.

In recent years the WIC program, a federal nutrition program for poor mothers and babies, has become a major playing field for ideological forces hoping to shape public opinion and Congressional action on matters of domestic social policy. WIC's highly positive benefits have been distorted, research results from its scientific evaluation altered by high-level federal officials, and its public support undermined by an academic spokesman with ties to the White House and a stated desire to kill the program. While strong bipartisan support on Capitol Hill makes it likely that WIC will survive and even grow, distortion of its record provides insight into how ideological forces contaminate the well of reasoned discourse for their preconceived ends.