An overview of folate status in a population-based study from São Paulo, Brazil and the potential impact of 10 years of national folic acid fortification policy.

BACKGROUND/OBJECTIVES: Food fortification is an important strategy in public health policy for controlling micronutrient malnutrition and a major contributing factor in the eradication of micronutrients' deficiencies. Approximately 50 countries worldwide have adopted food fortification with folic acid (FA). FA fortification of wheat and maize flours has been mandatory in Brazil since 2004. To assess the effect of 10 years of FA food fortification policy on folate status of residents of São Palo, Brazil using a population-based survey. SUBJECTS/METHODS: Data were from 750 individuals aged ⩾12 years who participated in a cross-sectional population-based survey in São Paulo city, Brazil. Fasting blood samples were collected, and folate was assayed by affinity-high performance liquid chromatografy method with electrochemical detection. The participants provided information about food intake based on two 24 h dietary recall. RESULTS: Only 1.76% of population had folate deficiency (<6.8 nmol/l). The mean folate concentration was 29.5 (95% confidence interval: 27.3-31.7) nmol/l for all sex-age groups. The mean folate intake for the population was 375.8 (s.e.m.=6.4) µg/day of dietary folate equivalents (DFEs). When comparing folate intake in DFE from food folate and FA from fortified foods, FA contributed 50% or more of the DFE in almost all sex-age groups. The major contributors of folate intake are processed foods made from wheat flour fortified with FA, especially among subjects younger than 20 years old. CONCLUSIONS: The deficiency of folate is very low, and food fortification contributed to folate intake and had a notable influence on rankings of food contributors of folate.

Comparisons of physical activity, adipokines, vitamin D status and dietary vitamin D intake among adolescents.

BACKGROUND: Considering that lifestyle and diet are key factors responsible for the increases in adiposity in youth, it is important to understand how vitamin D, adipokines and markers of glucose metabolism are related to physical activity level (PAL) during growth. The present study aimed to investigate associations between physical activity level, adiponectin/leptin ratio, vitamin D status and dietary vitamin D intake among adolescents. METHODS: A cross-sectional study was conducted with adolescents aged 14-18 years old who were living in São Paulo, Brazil. Serum 25 hydroxyvitamin D [25(OH)D], adiponectin (A), leptin (L), glucose and insulin were obtained after 12 h of fasting. Dietary calcium and vitamin D intake were measured by 24-h food record, as repeated in 62.6% of the sample. PAL was measured by the International Physical Activity Questionnaire (IPAQ). Pearson's chi-square test, Pearson correlation and linear regression analysis were performed. RESULTS: A total of 198 subjects, mean (SD) age 16.3 (1.4) years, 51% male, were enrolled in the study. Some 9% of participants were sedentary, 22% were insufficiently active (IA), 51% were active and 18% were very active (VA). The A/L ratio was lower among sedentary/IA subjects [2.2 (4.0) versus 5.6 (12.3); P = 0.01] compared to active/VA subjects. PAL was not associated with vitamin D status or markers of glucose metabolism. Serum 25(OH)D positively associated with vitamin D intake, after adjusting for sex, sun exposure and season of the year in regression analysis (partial r2 =0.026, P = 0.02). CONCLUSIONS: Low PAL was associated with a lower A/L ratio. Vitamin D status was not associated with sun exposure habits, although it was positively correlated with vitamin D intake.

Dietary intake and food contributors of polyphenols in adults and elderly adults of Sao Paulo: a population-based study.

A comprehensive estimation of polyphenol intake is needed to gain a better understanding of the association between polyphenol-rich food intake and the potential effects of this intake on chronic diseases. The aim of this study was to estimate the intake of polyphenols and the major dietary contributors in the population of Sao Paulo. Data were obtained from the Health Survey-São Paulo (ISA-Capital 2008) and were reported for 1103 adults and elderly adults. Food intake was estimated by one 24-h dietary recall (24HR). Polyphenol intake was calculated by matching food consumption data from the 24HR with the polyphenol content in foods listed in the Phenol-Explorer database. The mean total intake of polyphenols was 377·5 (se 15·3) mg/d. The main polyphenol classes were phenolic acids (284·8 (se 15·9) mg/d) and flavonoids (54·6 (se 3·5) mg/d). Intakes were higher in the elderly adults than in other adults (P<0·001) and higher in individuals with lower educational level (P=0·01) and current smokers (P=0·02). The main dietary contributors for total polyphenols were coffee (70·5 %), citrus fruits (4·6 %) and tropical fruits (3·4 %). Coffee was the major source of polyphenols, providing 266·2 (se 16·5) mg/d, and contributed 92·3 % of the phenolic acids and 93·1 % of the alkylmethoxyphenols. These findings will be useful for assessing the potential role on health of polyphenols and specific polyphenol-rich foods, such as coffee, and enable a comparison with people from other countries.

High intake of heterocyclic amines from meat is associated with oxidative stress.

High meat intake has been related to chronic diseases such as cancer and CVD. One hypothesis is that heterocyclic amines (HCA), which are formed during the cooking process of meat, can generate reactive species. These compounds can cause oxidation of lipids, proteins and DNA, resulting in oxidative stress, cell damage and loss of biological function. This association has been seen in vitro; however, it remains unclear in vivo. The aim of the present study was to investigate the association between oxidative stress and HCA intake, and oxidative stress and meat intake. Data were from the Health Survey for Sao Paulo--ISA-Capital (561 adult and elderly). Food intake was estimated by one 24-h dietary recall (24HR) complemented by a detailed FFQ with preferences of cooking methods and level of doneness for meat. HCA intake was estimated linking the meat from the 24HR to a database of HCA. Oxidative stress was estimated by malondialdehyde (MDA) concentration in the plasma, after derivatisation with thiobarbituric acid and quantification by HPLC/diode array. Analyses were performed using multivariate logistic regressions adjusted for smoking, sex, age, BMI, skin colour, energy intake, fruit and vegetable intake, and physical activity. A positive association between HCA intake and MDA concentration (OR 1·17; 95% CI 1·01, 1·38) was observed, showing that HCA from meat may contribute to increase oxidative stress, and may consequently increase the risk of chronic diseases.

Is the food frequency consumption essential as covariate to estimate usual intake of episodically consumed foods?

UNLABELLED: BACKGROUNDS/OBJECTIVES: The aim of this paper is to verify the performance of the frequency of consumption as variable for prediction of the usual intakes of foods. SUBJECTS/METHODS: In total, 725 individuals who answered two nonconsecutive 24-h recall and one food frequency questionnaire (FFQ) in the 'Healthy Survey-Sao Paulo-Brazil'. An additional indicator variable indicating if one is usual consumer was created before analyzing. The Multiple Source Method and National Cancer Institute method were used to estimate usual intake of selected food considering different models of prediction: with no covariates; with FFQ; with FFQ plus indicator variable; and with only indicator variable. RESULTS: For foods that are consumed every day or almost every day, the inclusion of the FFQ and/or the indicator variable as covariates resulted in similar percentiles of consumption when compared with the model with no covariates. For episodically consumed foods, the models with FFQ plus indicator variable and with only indicator variable estimated similar percentiles of intake. CONCLUSIONS: The use of the indicator variable instead the FFQ appears as a good alternative to estimate usual intake of episodically consumed foods.

Validation of a semi-quantitative adolescent food frequency questionnaire applied at a public school in São Paulo, Brazil.

OBJECTIVE: To develop a food frequency questionnaire for adolescents (AFFQ) and demonstrate its relative validity. DESIGN: The final version of the AFFQ was composed of 76 food items previously identified according to their contribution in nutrients and overall importance within the eating habits of this population group. The validation study, which was undertaken during a 6 month period (June to November 1999), was administered to a sample of 79 who answered at least three 24 h dietary recalls (R24 h) applied at intervals of 45 days and one AFFQ at the end of the study. Applying the paired t-test and calculating Pearson correlation coefficients on nutrient data, differences in the mean of nutrients were obtained. Correlation coefficients between the mean energy-adjusted nutrients computed by the two methods were calculated, and correction was made for within-person variability. Agreement was evaluated by distribution of the adolescents according to quartiles of consumption. LOCUS: A public school within the metropolitan region of São Paulo city. RESULTS: A high variability in the dietary intake of adolescents was observed, with high rates of variability for cholesterol, retinal and vitamin C. The Pearson correlation coefficients, after being adjusted and corrected for variability, ranged from 0.10 to 0.72 among females and from 0.16 and 0.91 among males. The mean correlation coefficient for the entire group was 0.52. CONCLUSIONS: These results indicate that the AFFQ provides a potentially reliable scale for categorizing individuals by level of past intake of most nutrients, excluding retinol and iron.

Lipid profile of nutrition students and its association with cardiovascular disease risk factors.

OBJECTIVE: To describe the lipid profile and to verify its relationship with cardiovascular disease risk factors in students at a public university in São Paulo. METHODS: After obtaining clinical, anthropomorphic, and lipid profile data from 118 students, variables of the lipid profile were related to other risk factors. RESULTS: The mean age of the students was 20.3 years (SD = 1.5). The risk of cardiovascular disease was characterized by a positive family history of ischemic heart disease in 38.9%; sedentariness in 35.6%; limiting and increased total and LDL-C cholesterol levels in 17.7% and 10.2%, respectively; decreased HDL-C levels in 11.1%; increased triglyceride levels in 11.1%; body mass index > 25 in 8.5%, and smoking in 6.7% of the subjects. Students' diet was found to be inadequate regarding protein, total fat, saturated fat, sodium, and fiber contents. A statistically significant association between cholesterol and contraceptive use, between HDL-C and contraceptive use, age and percent body fat, and triglycerides and percent lean weight was observed. CONCLUSION: A high prevalence of some risk factors of cardiovascular disease as well as the association between these factors with altered lipid profiles was observed in the young population studied.

Nutritional evaluation of children with phenylketonuria.

CONTEXT: Dietary phenylalanine (PA) restriction is the most effective form for reducing its excess in the blood and is the only efficient method for treating phenylketonuria. The diet is complex and should be adapted to combine the patients' eating habits, growth and development. It depends basically on the use of industrialized products as substitutes free of PA for proteins that are not fully supplied. OBJECTIVE: To evaluate the nutritional status of children with phenylketonuria (PKU) by anthropometric measurements and food intake. DESIGN: Cross-sectional study. SETTING: Children with PKU attending the Association of Parents and Friends of Handicapped Children (Associação de Pais e Amigos dos Excepcionais - APAE) and normal children attending at municipal day care centers in São Paulo. PARTICIPANTS: 42 children with PKU and 31 normal children aged 1 to 12 of both sexes were assessed in two groups, under and over 7 years of age. MAIN MEASUREMENTS: Weight and height measurements. RESULTS: Children with PKU ingested calories, calcium, iron, zinc, and copper below the recommended values, whereas the protein intake was within the normal range. Food intake in the group of normal children was within normality rates. The height/weight Z-score means for children with PKU were 0.47 for those under 7 years and 1.86 for 7 year-olds and over; in normal children the means were 0.97 <7 years and 1.54 >/=7 years, with no statistically significant difference. The height/age Z-score means were significantly lower in the PKU children <7 years (-1.23) than in the normal controls (0.91). CONCLUSIONS: The data presented demonstrate the importance of nutritional surveillance in patients with PKU so as to support adequacy of nutrient intake and to guarantee growth within the relevant standards.

Plasma zinc, copper, and erythrocyte superoxide dismutase in children with phenylketonuria.

Children with phenylketonuria (PKU) are treated with semisynthetic diets restricted in phenylalanine (PHE). The formulae must supply those trace elements and vitamins that are usually supplied by whole protein foods. We studied the effects of phenylalaline restricted diets in 42 children with PKU (P) and 31 normal (N) children, aged 1-12 y, divided into two groups (below and above 7 y). Plasma zinc and copper were analyzed by means of atomic spectrophotometry, and superoxide dismutase (CuZnSOD) activity was measured in erythrocytes, through NBT inhibition and its profile, as determined by isoelectric focalization. Plasma zinc of PKU children > or = 7 years old was significantly lower than that in the control group (17 mumol/L versus 20 mumol/L) but still within the normal range; in children < 7 years no substantial differences were found between the two groups. Plasma copper was not statistically different between PKU and normal children. Qualitative activity of CuZnSOD presented the same electrophoretic profile in both normal and PKU. Quantitative activity was not different in both P (1210 U/g Hb < 7 versus 1328 U/g hemoglobin (Hb) > or = 7) and N (1675 U/g Hb < 7 versus 1367 U/g Hb > or = 7). We concluded that children with PKU presented normal mean levels of zinc and copper, with preserved function, measured by enzyme activity.