Effects of calcium and phosphorus intake and excretion on bone density in postmenopausal women in Hermosillo, Mexico.

Calcium (Ca) is important in bone formation and as aging progresses, bone loss gradually occurs. With the onset of menopause, reduced estrogen levels and insufficient Ca in the diet often create serious problems with fractures. Since little is known about the diet and other factors related to risk factors in postmenopausal women in northern Mexico, it was the objective of this study to determine the effects of dietary Ca and phosphorus (P) and their excretion, anthropometric measurements, and blood serum estradiol on bone density in women aged 45-63 years. No studies are available on the dietary intake of Ca and P and the effects on bone mineral density (BMD) in postmenopausal women in northern Mexico, so this study reports some of the first data on this population. Women with an average age of 55 years showed a positive relation of Ca intake and Ca excretion, however, dietary intake of Ca and P had no relation to bone density. Age, urinary Ca, Ca/creatinine and years of postmenopause had the highest negative correlation. Weight and body mass index had a positive correlation with BMD in the forearm and heel. Only 15% of the women met the recommendation of 1,500 mg/day of Ca. A high Ca/creatinine ratio has been proposed to indicate excess Ca excretion and subsequent bone density loss. Thirty-five percent of the women exceed the Ca/creatinine indicator of >0.16. In this study, 1% of the subjects were classified as osteoporotic and 37% as osteopenic.

Consumo de ácido ascórbico y niveles séricos en hombres adultos fumadores y no fumadores de la CD. de Hermosillo, Sonora, México / Ascorbic acid consumption and serum levels in smokers and non-smokers adult men in Hermosillo, Sonora, México

Ascorbic acid is one of the important antioxidant nutrients that can aid in the prevention of oxidative cellular damage. Adequate dietary intake is essential as humans can not synthesize this vitamin. It has been reported that smokers require higher dietary intakes to maintain their serum levels. The objective of this study was to determine serum levels of ascorbic acid in young male smokers and non smokers in the city of Hermosillo, Sonora, Mexico. In addition, their dietary intake of ascorbic acid was determined by a 24 h dietary recall. The dietary intake of ascorbic acid in 12 smokers was 64 +/- 11 mg/d and in 13 non smokers it was 70 +/- 12 mg/d. The smokers in this study did not meet the dietary recommendation of 100 mg/d. Serum ascorbic acid values in smokers and non smokers were 24.2 +/- 6.9 mumol/L and 30.9 +/- 3.7 mumol/L respectively. No significant difference was found among the 2 groups. Although the average serum ascorbic acid values fell within the range considered normal, 50 per cent of the smokers had individual values that were below 23 mumol/L, indicating that these subjects have hipovitaminosis. A positive correlation between intake and serum levels was obtained for smokers (r = 0.71; p = 0.03). The results of this study suggest smokers may be at increased risk for chronic diseases due to their low intake and low serum levels of ascorbic acid.

Prevalence of undernutrition and iron deficiency in pre-school children from different socioeconomic regions in the city of Oaxaca, Oaxaca, Mexico.

Lack of adequate food and in particular high quality protein, is one of the causes of malnutrition in children which could result in retarded growth. Iron deficiency is common in populations where protein sources are of vegetable origin; however in northern Mexico where the bean consumption is high, anemia is not a problem. The primary staples in the Mexican diet are corn tortillas and beans. The objective of this study was to evaluate the anthropometric condition of children 4-6 years old living in the city of Oaxaca, Oaxaca, Mexico and to determine the prevalence of anemia. Mean Z scores for children 4-6 years old living in poor conditions in the city of Oaxaca, Oaxaca, Mexico showed significant differences between socioeconomic groups (p<0.002) for height/age (H/A) and weight/age (W/A) (p<0.001) after adjusting for age and sex. Weight/height (W/H) was not different (p=0.30). By using the Waterlow classification system, 28.8% of the pre-school children of this study were stunted and only 0.9% were classified as wasted. There were no children that presented both stunting and wasting. Iron deficiency was very prevalent in both boys and girls, ranging from 56-79% depending on the indicator used. When classified by the combination of serum ferritin, % transferrin saturation and hemoglobin values, 23.7% of the children were classified as anemic, 11.9% in a state of iron deficiency and 13.6% with low iron reserves.

Protein quality evaluation in rats of typical diets for 4- to 6-year-old children from different socioeconomic areas living in Oaxaca, Mexico.

Legumes and cereals are principal sources of energy and protein in developing countries. In Oaxaca, Mexico, corn is the primary agricultural crop, therefore corn tortillas and beans are the main energy and protein sources. The objective of this study was to evaluate the protein quality in rats of typical diets for 4- to 6-year-old children from different socioeconomic areas in Oaxaca, Mexico. Composite diets representing the typical diets were formulated and fed to male weanling rats for 10 days. A control diet using casein as the reference diet and one free of nitrogen were included in the study. The apparent protein digestibility was determined in rats using the chromic oxide marker technique and the data was statistically analyzed for differences between control and experimental diets. Rats fed the diet of low income children gained about 2 g/day compared to about 3.8 g/day for the rats fed the control (casein) diet and had the lowest weight gain/g of protein intake. The NPR was 3.52 compared to 4.31 for the control diet. This diet is 67% vegetable protein and 33% animal protein. The diet for the medium income group contained a higher percentage of animal protein, 76% and thus higher digestibility, 78%. The results of this study indicate that the protein quality of children's diets in Oaxaca, Mexico, need to be improved.

Nutrient intake and growth of preschool children from different socioeconomic regions in the city of oaxaca, México.

Dietary intake and anthropometric measurements were determined in 124 preschool children, aged 4-6 years, living in the city of Oaxaca, México. The children were classified by socioeconomic status, depending upon their living conditions and family income. A composite diet representing the typical diet according to socioeconomic group was formulated and chemically evaluated. Corn tortillas and beans were the primary protein and energy sources for the children of this study. The inclusion of dairy products, animal products, and fruits and vegetables was not common. The children in the low-income group, which represents the majority of the children of this area, received only 63% of the recommended intake. Also for the low-income group, protein and iron recommendations were met but by plant-based sources. Protein contributed 10% of the energy, 78% were from carbohydrates and 12% from fat. Calcium intake was low, meeting only 34% of the recommendation and zinc intake was 51%. Fiber intake was very high, coming primarily from beans and tortillas. In the low- income group, Z scores for height and age were -1.60 for boys and -1.75 for girls. Weight-for-age Z scores were -0.90 and -0.97 for boys and girls, respectively. The weight-for-height Z scores for this group were 0.33 and 0.12 for boys and girls, respectively. Although energy needs were not met, extreme stunting was not detected.

[Content and absorption of calcium in diets of Northwestern Mexico: a bibliographic retrospective]. / Contenido y absorción del calcio proveniente de la dieta del noroeste de México. Una retrospectiva bibliográfica.

Calcium is an essential mineral in humans for growth and development of bones and teeth. In adults, bone activity is limited to maintaining bone mass and in order to do this, an adequate intake of calcium is necessary. The objective of this study was to conduct a review of the information available in the literature on the content and availability of calcium in the diet in Northwestern Mexico. The diet studies show that the amount of calcium (1164 mg/d) in the diets in Northwestern Mexico meets the RDA for adults 25 or older and that the principal sources of calcium are corn tortillas, wheat flour tortillas and beans. Bioavailability of calcium in diets containing these foods increases when small amounts of dairy products are added to the diet. This same difference in the availability of calcium was observed in an in vivo study conducted in young women. We can conclude, based on the studies mentioned, that it is necessary to evaluate the effect of calcium in the diets of Northwestern Mexico directly in the general population taking into consideration factors that may play a role in maintaining bone structure such as exercise, age, sex.

Excretion of arsenic (As) in urine of children, 7-11 years, exposed to elevated levels of As in the city water supply in Hermosillo, Sonora, México.

Arsenic (As) is a common element in the environment with many industrial uses, but it also can be a contaminant in drinking water and present serious health concerns. Earlier studies on the quality of drinking water in the city of Hermosillo, Sonora, México, showed high levels of As (> 0.05 ppm) in water from wells located in the northern part of the city. Additionally a high positive correlation between the levels of Fluoride (F) and As in the same wells was found. Therefore, the objective of this study was to determine the excretion of As in children, 7-11 years of age, that had been exposed to elevated levels of As in their drinking water. Twenty-four-hour urine samples and a water sample taken directly in the home were collected from school age children living in two different areas with known high levels of As in their drinking water. A control group with normal levels of As in their water was also included. As was determined by an atomic absorption-hydride generator, verified with the use of NBS certified standards (SRM 1643a and SRM 2670). None of the water samples exceeded the limit established for drinking water; however, there was a significant difference between the intake of As and the As in drinking water among the three areas of the study. Average As in water was 0.009 +/- 0.002 and 0.030 +/- 0.011 micrograms/ml between the control and high areas. Intake (in micrograms/day) was 15 +/- 3 and 54 +/- 18. In the group consuming water with high levels of As, 65% of the children exceeded the recommended dose of < 1 micrograms/kg/day (EPA, 1988). Several children in this study also had high levels of As in their urine. Even though As levels in the drinking water are within the norms, it appears that children exposed to high levels of As in their drinking water may have a health risk.

Incidence of heavy metal contamination in water supplies in northern Mexico.

Contaminants in drinking water present public health risks. The objective of this study was to analyze water samples taken from wells or storage tanks, direct sources for domestic water in Northern Mexico, for the presence of lead (Pb), copper (Cu), cadmium (Cd), arsenic (As), and mercury (Hg). The samples were analyzed by atomic absorption coupled with a hydride generator or a graphite furnace. High levels of Pb (0.05-0.12 ppm) were found in Hermosillo, Guaymas, and Nacozari. Forty-three percent of the samples in Sonora exceeded the action level (0.015 ppm) established by the EPA for Pb. For As, 8.92% exceeded the limit with a range of 0.002-0.305 ppm. Several studies have indicated a possible link between As and fluoride (F) in drinking water. This study showed a positive correlation between F and As (r = 0.53, P = 0.01, and n = 116). One location in Hermosillo had 7.36 ppm of F and 0.117 ppm of As, 3.5 times the recommended F levels in drinking water and 2 times higher than the level permitted for As. Hg contamination was found in 42% of the samples. Based on the results of this study, it appears that As, Hg, and Pb contamination in the drinking water for some areas of the state of Sonora is a major concern.

Evaluation of the composition of the regional diet in Sonora, México: incidence of colon cancer.

Diet is responsible for about one third of the cancers. Dietary fiber, energy intake, fat and consumption of fruits and vegetables play an important role in different cancers. The regional Mexican diet is characterized as being high in dietary fiber, high in fat and energy but very low in fruits and vegetables. The diet is high in insoluble fiber and phytate. The objective of this study was to evaluate the composition of the regional diet and relate this composition to the incidence of colon cancer in the northern region of México. Two traditional diets, one higher in fruits and vegetables, but both high in fat and dietary fiber were evaluated. A mathematical expression showed the typical regional diet to be low in antioxidant nutrients, even though an earlier study showed it to have a tendency to protect against colon cancer. During the years of 1991-1995, Sonora, México reported about 20 cases/ 100,000 inhabitants of colon cancer. This incidence is low compared to other regions and high dietary fiber is thought to be responsible. If antioxidant nutrient intake was elevated, possibly a greater protection could be achieved.

Colon cancer in rats and diet in the Sonoran desert region of Mexico.

The role of dietary fiber in colon cancer is still not clear. Epidemiological studies suggest a protective role for high fiber intake. However the data suggest that the effects of fiber must be considered in the context of the total diet and its interactions with other dietary components. The typical Sonora diet is high in dietary fiber (7.8%) and the majority of this fiber (71%) is insoluble. Comparing the incidence of colon cancer in Sonora with its neighboring state of Arizona, in 1991, Sonora reported 40 cases of colon cancer, a population of 1,823,606, compared to 1432 for Arizona (3,763,322 inhabitants). The typical regional diet was evaluated for its protective effect in the development of colon cancer in rats injected with azoxymethane, AOM. The regional diet showed a tendency to protect against colon cancer, an incidence of 45% compared to 66% for the control diet, although this effect was not significant (p = 0.15). Further studies are needed to fully evaluate the diet and certain interactive dietary factors such as fat, quantity as well as type, protein, calcium and antioxidant nutrients.

[Comparison of analized and calculated energy, fat, protein, dietary fiber, iron and zinc values in diets from different socioeconomic levels in northern México]. / Comparación entre los valores analizados y calculados del contenido deenergía, grasa, proteína, fibra dietética, hierro y zinc en dietas del noroeste de México de diferentes niveles socioeconómicos.

Traditional methods of dietary assessment such as measuring nutrient intake with 24 h dietary recalls, food frequency questionnaires and multiple-day food records, depend upon the use of data base systems to estimate nutrient data. Certain problems exist with the data from these sources. For Mexico, the most serious one is that in many of the systems certain nutrient data is lacking and many of the traditional foods are not included. The objective of this study was to analyze regional diets for protein, fat, dietary fiber, iron and zinc and compare these values with those estimated from two different data bases, ALIM 10.000 which includes regional dishes and foods and Nutritionist III, which includes data from Handbook 8. Energy values were calculated using reported values. The results showed that the bases produced comparable values to those analyzed for energy, protein, fat, however for micronutrients the data bases generally overestimate the analyzed values. The results of this study emphasize the need to update data bases with new product information, re-examine certain values on basis of newer methods, and to include data for ethnic foods.