Interactions among indicators of B1, B2, B6 and vitamin C status in university students.

In 209 young university students (109 males and 80 females) with body mass index within the normal range, the activation coefficient of the erythrocyte transketolase (ETKAC) glutathione reductase (EGRAC) and aspartate amino transferase (EASTAC) as well as the circulating levels of vitamin C were determined. Using the usual cutoff points for ETKAC and serum vitamin C and higher than usual cutoff points for EASTAC and EGRAC 99, 95, 92, and 87% of the study subjects exhibited activation coefficients which were compatible with an acceptable status for vitamin B2, B6, C and B1 respectively. A correlation analysis showed a high correlation (r = 0.81) between erythrocyte indicators of B1 and B2 status a lower correlation between indicators of the status of these vitamins and B6 and no correlation between the indicators of B1, B2, and B6 status and serum vitamin C. This study indicated that in this largely nutritionally adequate population, the activation coefficient of the erythrocyte enzymes used here as markers of the nutritional status of B1, B2, and B6 were related between themselves and varied in the same direction. These changes, however, were not associated with circulating levels of vitamin C.

Interactions among indicators of B1, B2, B6 and vitamin C status in university students

In 209 young university students (109 males and 80 females) with body mass index within the normal range, the activation coefficient of the erythrocyte transketolase (ETKAC) glutathione reductase (EGRAC) and aspartate amino transferase (EASTAC) as well as the circulating levels of vitamin C were determined. Using the usual cutoff points for ETKAC and serum vitamin C and higher than usual cutoff points for EASTAC and EGRAC 99, 95, 92, and 87 per cent of the study subjects exhibited activation coefficients which were compatible with an acceptable status for vitamin B2, B6, C and B1 respectively. A correlation analysis showed a high correlation (r = 0.81) between erythrocyte indicators of B1 and B2 status a lower correlation between indicators of the status of these vitamins and B6 and no correlation between the indicators of B1, B2, and B6 status and serum vitamin C. This study indicated that in this largely nutritionally adequate population, the activation coefficient of the erythrocyte enzymes used here as markers of the nutritional status of B1, B2, and B6 were related between themselves and varied in the same direction. These changes, however, were not associated with circulating levels of vitamin C.

[Macronutrients, fiber, fatty acids and minerals in meals served in a university dining room]. / Macronutrientes, fibra, ácidos grasos y minerales en almuerzos servidos en un comedor universitario.

We studied the nutritional quality of six lunch menus offered in a university's dining room located in Caracas City. Each of these menus included soup, main dish, salad, bread and dessert. The results showed that each lunch offered 15 to 20 different kinds of foods. Comparing the results of the chemical analysis of the edible part of these lunch menus with the requirements of the students users of the university dining room, indicated that on the average, they offered 37% and 57% of the energy and protein requirements, 30% to 50% of the iron requirements and a substantial amount of dietary fiber. Their fat concentration, according to the dietary habits of the venezuelan population, was low and ranged from 15% to 25% of the total calories. The analysis of the fatty acids present in two of the six studied menus, showed that the proportion of saturated: monoinsaturated: polyinsaturated was approximately 2:1:1. Despite the predominance of the saturated, the proportion of the total calories present in these lunch menus, provided by these fatty acids, was on the average less than 10%. In addition, these meals offered more sodium than potassium and the calculated amount of sodium chloride they provided, was close to the total amount recommended to be consumed in a day. In general, the results of this study, showed that the lunch offered by this university dining room can fulfill an important proportion of the students' nutritional requirements, providing at the same time a meal adjusted to modern nutritional guidelines for good health. The results also emphasize the advantages of the traditional Venezuelan food, since the Venezuelan national plate, had the least amount of fat and salt of all the menus here analyzed.

Absorción de grasa proveniente de tres fuentes dietarias en ratas con diarrea inducida con lactosa / Absorption of fat from three dietary sources in rats with lactose induced diarrhea

Low energy intake is one the most important factors related to nutritional wasting during diarrheal episodes and fat is the macronutrient with the highest energy value. So we intended to seek dietary fat sources, with the highest bioavailability during diarrheal episodes. Three basal (control) and three 42.8 lactose containing diets, used to induce diarrhea, were prepared with corn oil, butterfat or lard. The assay included 48 Sprague-Dawley rats, 28 d of age, initial weights of 65.5 +/- 5.2 g, distributed in 6 groups that received the diets during 15 d. The different types of fat did not affect diet intake, weight gain or fecal losses in rats without diarrhea (control). Low weight gain was found in rats with diarrhea regardless of the type of fat consumed and was related to low diet consumption. Mean fat absorption during diarrhea was as follows: butterfat 84, lard 87 and corn oil 91. The latter was related to lower fecal losses and higher fat absorption during the 15 d study. Considering that the three fat sources evaluated are easily purchased and widely accepted, and that nutritional management of subjects with diarrhea includes the intake of energy dense diets, it seems that the use of corn oil in these formulations could offer greater advantages.

[Absorption of fat from three dietary sources in rats with lactose induced diarrhea]. / Absorción de grasa proveniente de tres fuentes dietarias en ratas con diarrea inducida con lactosa.

Low energy intake is one the most important factors related to nutritional wasting during diarrheal episodes and fat is the macronutrient with the highest energy value. So we intended to seek dietary fat sources, with the highest bioavailability during diarrheal episodes. Three basal (control) and three 42.8% lactose containing diets, used to induce diarrhea, were prepared with corn oil, butterfat or lard. The assay included 48 Sprague-Dawley rats, 28 d of age, initial weights of 65.5 +/- 5.2 g, distributed in 6 groups that received the diets during 15 d. The different types of fat did not affect diet intake, weight gain or fecal losses in rats without diarrhea (control). Low weight gain was found in rats with diarrhea regardless of the type of fat consumed and was related to low diet consumption. Mean fat absorption during diarrhea was as follows: butterfat 84%, lard 87% and corn oil 91%. The latter was related to lower fecal losses and higher fat absorption during the 15 d study. Considering that the three fat sources evaluated are easily purchased and widely accepted, and that nutritional management of subjects with diarrhea includes the intake of energy dense diets, it seems that the use of corn oil in these formulations could offer greater advantages.

[Effect of the lactose induced diarrhea on macronutrients availability and immune function in well-nourished and undernourished rats]. / Effecto de la diarrea inducida con lactosa sobre la disponibilidad de los macronutrientes y la función inmune en ratas nutridas y desnutridas.

In this study we compared the availability of nutrients in a balanced diet offered to young well-nourished and undernourished Sprague Dawley rats, with and without diarrhea. Malnutrition was induced by restricting food intake (50%) in one half of the rats for 2 weeks and diarrhea was induced by including 45% lactose in the diet after malnutrition had been established. During the experiment which lasted 8 d the animals were kept on the same feeding protocol but one half of the nourished and one half of the undernourished received lactose to induce diarrhea. The results showed that the inclusion of lactose at 45% in the diet caused a severe diarrhea both in the nourished and undernourished rats. This diarrhea however, resulted in a reduction in food intake and growth only in the well-nourished rats. In the rats with diarrhea the apparent digestibility of the diet and of its macronutrients decreased compared with the animals without diarrhea but this reduction was less apparent in the undernourished rats. Similar results were obtained in relation to the retention of nitrogen and energy. In this case, diarrhea was associated with retentions which were lower than those seen in the rats without diarrhea but the undernourished rats with diarrhea retained more energy than the well-nourished rats with diarrhea. Malnutrition resulted in lower packed cell volume, leukocyte count and thymus weight but diarrhea in the malnourished rats did not cause a further reduction in these variables as it did in the well-nourished animals. In general, these results indicate that in well-nourished rats, diarrhea had a negative effect whereas in the undernourished group it did not. It appears that the undernourished rats compensated their nutrient utilization so that diarrhea did not worsen their undernourished condition.

[Nutrient utilization in children with acute diarrhea fed with formulas containing chicken and soybean]. / Utilización de nutrientes en niños con diarrea aguda alimentados con formula a base de pollo y de soya.

The objective of this study was to measure in children with acute diarrhea the apparent absorption and retention of the macronutrients and some micronutrient present in a formula prepared with chicken and a formula prepared with soybean protein. Fourteen male children (9 months old) with acute diarrhea were assigned to each of these formulas and the consumption and excretion of the studied nutrients were monitored during 48 h. The results showed that the children assigned to the chicken formula consumed more protein and less fat than those in the soybean protein formula. These differences however were associated with differences in the composition of the formulas offered rather than to differences in protein or fat utilization. Fecal mass (800 g/48 h) was similar in both groups and the macronutrient content of the feces, reflected well the amount consumed. The apparent absorption of fat (63%), nitrogen (75%) and carbohydrates (78%) resulted similar in both groups and there were no differences in the retention of nitrogen which approximated 55%. The digestible energy and the metabolizable energy of both formulas, also resulted equal. In general the children excreted more urinary ammonia and less creatinine than healthy children but there were no differences in the excretion of these metabolites between the children assigned to the chicken or to the soybean protein formulas. The retention of Zn (47%) and Ca (72%) were also similar in both groups and they excreted a high (0.17 mg/48 hr) but similar amount of Vitamin A. In summary, these results showed that from a nutritional point of view, the chicken and the soybean protein formulas were equally utilized during the acute phase of diarrhea.

In well-fed young rats, lactose-induced chronic diarrhea reduces the apparent absorption of vitamins A and E and affects preferentially vitamin E status.

To establish the effect of lactose-induced diarrhea on the apparent absorption and status of vitamins-A and E in well-fed young rats, we fed Sprague Dawley rats a balanced diet or a lactose diet (350 g/kg). A group of rats fed the control diet equal to the level measured in the lactose-fed rats (pair-fed) was also included. The experiment lasted 23 d and feces were collected on days 4-6, 10-12, 14-16 and 20-22. Samples of serum and tissues were taken on days 10 and 23. Lactose caused a significant reduction in food intake, had no effect on body weight and produced a diarrhea that persisted during the whole experiment. The severity of diarrhea decreased with time, indicating that the rats partially adapted to lactose feeding. At the onset of diarrhea, the apparent absorption of vitamins A and E in the rats with diarrhea was significantly lower than in the control or pair-fed rats, but the rats with diarrhea recovered gradually, and in the case of vitamin E was normalized by day 15. At day 10 the rats with lactose-induced diarrhea had serum and liver concentrations of vitamins A and E that did not differ from the control or pair-fed rats. However, at day 23 the lactose-fed rats with diarrhea had significantly lower serum and liver concentrations of vitamin E than the control or pair-fed rats. Measured at that time, diarrhea had no effect on liver vitamin A, but lower serum concentrations of this vitamin were detected in both the lactose-fed rats and in the pair-fed rats. In general, in well-nourished rats, the chronic diarrhea associated with excessive dietary lactose reduced the apparent absorption of vitamin A and E and particularly compromised the nutritional status of vitamin E.

[Serum lipids and vitamin A, C and E concentrations in an adult population of Caracas City]. / Lípidos séricos y niveles de las vitaminas A, C y E en una población adulta de la ciudad de Caracas.

Lipid profiles as well as vitamins A, C and E were determined in a sample of 90 men and 151 women with ages within 35 and 50 years old. Comparing the lipid profiles obtained in the study with the limits established by the National Cholesterol Education Program, resulted that a little more than 60% of the group had total cholesterol and LDL cholesterol levels in the desirable range, 20 to 30% had levels in the marginal range while 10 to 15% had levels in the high risk range. This distribution of the risk is more favorable than that observed in populations with a high risk of heart diseases such us the British or American populations, which show a substantially higher segment of the people in the high risk level. When the protective effect of the HDL cholesterol was included in the estimation of the risk by calculating the indexes: Total cholesterol/HDL chol., LDL Chol/HDL chol. or Total Chol-HDL chol. 65 to 80% of the population had values within the normal range and the first of these indexes, indicated that the men had a higher risk than the women. Integrating both methods of estimating the risk and considering that the risk of the individuals in the marginal range defined by the National Cholesterol Education Program is minimal unless they have two additional risk factors, it appears that an important segment (20-30%) of the studied population may benefit from programs aiming to reduce other risk factors such as smoking, high blood pressure, diabetes or overweight. The vitamin levels measured in this study indicated that the vast majority of the population had their levels in the safe range but an important segment had vitamin C serum levels indicative of poor consumption of this vitamin. Since vitamin C is high in fruits and vegetables we concluded that the studied population had a low consumption of these foods. Due to the existing evidence of a protective effect of fruits and vegetables in heart and other chronic diseases it was concluded that institutions such as the one studied here should engage in preventive campaigns emphasizing a reduction of both risk factors and the consumption of saturated fats. The results of this study also indicate that the consumption of fruits and vegetables should be encouraged.

[The effect of lactation time on the macronutrient and mineral composition of milk from Venezuelan women]. / Variaciones temporales en la composición y aporte de macronutrientes y minerales en leches maternas de mujeres venezolanas.

Human milk is considered the ideal food for the infant and it has been extensively used to estimate its nutrient requirements. The objective of this paper was to determine the effect of lactation time on the macronutrient an mineral content of milks obtained from Venezuelan women and also to compare this with the established nutrient requirements of the infant. For this purpose 83 milk samples from 45 low income mothers were analyzed at the colostrum (48 h to 54 d) and mature states of lactation (1.3 and 6 months). The results showed that colostrum had a higher protein and a lower fat content than mature milks whereas its content of energy and carbohydrate was similar to mature milk. The iron and calcium content of the milk remained unchanged during the whole study whereas Zn and Cu decreased and increased with lactation time respectively. In contrast, phosphorous and magnesium increased up to 3rd month of lactation and remained constant there after. The macronutrient content of 850 ml of the analyzed milk almost completely fulfilled the daily infant requirements established in the US (RDA) and Canada (RNI). The mineral content of this volume of milk however was insufficient to cover the infants requirements particularly those established in the US. The most notorious deficiency in these milks was in Fe since they could fulfill only 11% the infants RDA for this mineral. The infant mineral requirements established in Canada are substantially lower than those defined in the US and therefore the analyzed milks could totally fulfill the Canadian infant daily requirements of Mg, Fe and Ca and more than 70% and 80% of the requirements of Zn and P. In general, the results of this study showed that the nutrient content of the analyzed milks agree well with those reported in the literature for women from different parts of the world including developed and underdeveloped areas. At the same time they pointed out the differences in the definition of the infant nutrient requirements set by different countries and also emphasize the fact that human milk, which by definition is the natural source of nutrients for the human infant apparently is incapable of fulfilling its daily requirements.

[Agreement between animal and vegetable protein digestibility measured in vivo and in vitro and its effect on the chemical score]. / Grado de concordancia entre la digestibilidad de proteínas animales y vegetales medidas in vivo e in vitro y su efecto sobre el computo químico.

Protein digestibility is a key factor in the determination of protein quality using the chemical score. Since there are several methods available for determining protein digestibility the purpose of this study was to compare three methods in vitro (pH drop, pH stat and pepsin digestibility) and two methods in vivo (true and apparent digestibility in rats) in the determination of the protein digestibility of: casein, soy protein isolate, fish meal, black beans, corn meal and wheat flour. The results showed that in the case of highly digestible proteins all methods agreed very well. However, this agreement was much less apparent in the case of protein with digestibilities below 85%. As a result, the chemical score of these proteins varied substantially depending upon the method used to determine its digestibility. Thus, when the chemical score of the proteins analyzed was corrected by the true protein digestibility measured in rats, they ranked as: casein 83.56, soy 76.11, corn-beans mixtures (1:1) 58.14, fish meal 55.25, black beans 47.93, corn meal 46.06 and wheat flour 32.77. In contrast, when the chemical score of these proteins was corrected by the pepsin digestibility method, the lowest quality was assigned to fish meal. In summary, this results pointed out that for non conventional proteins of for known proteins which have been subjected to processing, protein digestibility should be measured in vivo.

Application of a colorimetric method to the determination of the protein content of commercial foods, mixed human diets and nitrogen losses in infantile diarrhoea.

Recently we reported on the application of a method for protein determination which measures nitrogen in Kjeldahl digests colorimetrically. This procedure has the advantage of eliminating the distillation and titration steps of the Kjeldahl method and it is ideal for nutritional studies, since many samples can be run in a single day. Accordingly, the purpose of the present report was to extend the application of this method to the determination of the protein content of commercially available foods such as dairy products, dry cereals or cereal based products and legumes and also to evaluate this method in the determination of the protein content of the mixtures of cooked foods served during lunch at the cafeteria of the Universidad Simón Bolívar, Caracas. In both cases the results of the colorimetric nitrogen agreed very well with those obtained by the macro Kjeldahl, indicating that the colorimetric method may be used in monitoring the protein content of commercial foods and in evaluating the protein offered in institutional food services. Finally, to further demonstrate the value of this method in clinical trials, we used it to monitor the daily nitrogen intake and nitrogen losses in 43 male young children with acute diarrhoea, and 15 with persistent diarrhoea fed liquid formulae, and showed that protein digestibility and retention were higher in persistent than in acute diarrhoea. The severity of acute diarrhoea affected negatively (r = -0.62) the percentage of protein absorbed, whereas the protein absorbed (r = 0.70) and retained (r = 0.55) correlated positively with protein consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutritional evaluation of the soy-whey milk analog La colina.

The milk analog La colina is a product which contains mainly whey, soy protein isolate and vegetable oil, designed for infants since one year, children, adolescents and adults of all ages. The concept behind this product is to offer an alternative to milk consumption which during the last decade has decreased dramatically in Venezuela mainly due to its high price and low availability. Accordingly, the purpose of this study was to evaluate nutritionally this new product in order to determine if from a nutritional stand point it could represent a valid alternative to milk consumption. The results showed that La Colina offers the same amount of protein, energy, vitamin A, calcium, phosphorus and potassium as whole milk powder and more sodium, iron and zinc. In addition, a rat assay showed that the energy in these two products is equally available and even though the proteins in La colina are 3.9% less digestible, their quality determined by growth, PER or the nitrogen retained are excellent and identical to the quality of the proteins in milk. These results agreed with the theoretical chemical score of the proteins of this new product, which indicated that the amino acid profile of the mixture can fulfill the amino acid requirements of children, adolescents an adults. Both milk and La colina are products with a high fat content. The fat in this new product however, is vegetable oil and therefore it has a more convenient fatty acid profile than whole milk and about one third of its cholesterol. In short, these results showed that La Colina from a nutritional point of view is an excellent alternative to milk consumption.

[Minimal time for detecting protein quality using indicators of protein catabolism in chickens]. / Tiempo mínimo para detectar calidad proteica usando indicadores del catabolismo proteico en pollos.

Previous studies shown that in chickens the hepatic activities of the purine enzymes Xanthine Dehydrogenase and Nucleoside Phosphorylase and the uric acid excretion can predict the quality of the protein consumed in a very short time. In these studies even though the experimental time was short, the time used for the conditioning of the chickens was long and included five days with six chickens per cage and then five to six days for progressively changing the chickens to individual cages in order to avoid the stress associated with the isolation of the animals. Thus the purpose of this study was to determine the minimal time required to detect differences in these parameters after feeding a soy-met and a gelatin diet and eliminating completely the time required for the isolation of the chickens. Thus, 76 one day old Warren male chickens were placed in groups of six on a soy-met powdered diet during five days and on day six all the chicken were placed in individual cages and one halve was offered the same diet while the rest received a gelatin diet. Then on day 1, 2, 3, 5, 7, 10 and 15 after the diet change five chickens on each diet were sacrificed and the activity of the liver purine enzymes as well as the uric acid excreted were determined.(ABSTRACT TRUNCATED AT 250 WORDS)