Search

Flavonoids are a broad group of bioactive compounds with anticarcinogenic effects on the prostate that have been scarcely evaluated in Latin American populations. Our objective was to evaluate the association between dietary patterns of flavonoid intake and prostate cancer (PC) in a population-based case–control study carried out in Mexico City. Based on a semi-quantitative FFQ with a frame reference of 3 years before diagnosis or interview, we used an updated database for estimating the daily intake (mg/d) of flavones, flavonols and flavanols for 395 confirmed incident PC cases and 797 population controls matched by age (± 5 years). Histological PC differentiation was evaluated using the Gleason score at diagnosis. Flavonoid dietary intake patterns (FDIP) were determined through principal component analysis, and their association with PC was estimated using logistic regression models. Three FDIP were identified: gallate pattern (GP) characterised by (–)-epicatechin-3-O-gallate, (–)-epigallocatechin-3-O-gallate and (+)-gallocatechin; luteolin pattern (LP) characterised by luteolin and (–)-epigallocatechin-3-O-gallate; and a mixed pattern (MP) that included (+)-catechin, (–)-epicatechin and quercetin. A higher GP (ORT3 v.T1 = 0·47; 95 % CI 0·33, 0·66) and LP intake (ORT3 v. T1 = 0·39; 95 % CI 0·27, 0·59) were associated with a decreased PC likelihood. In contrast, a higher MP intake (ORT3 v. T1 = 2·32; 95 % CI 1·67, 3·23) increased PC likelihood. The possible differential and synergistic anticarcinogenic role of flavonoid compounds in PC deserves further study.

Objetivo. Resumir la evidencia científica sobre las altera­ciones renales asociadas con la infección por SARS-CoV-2. Material y métodos. Se realizó una revisión rápida con la metodología Cochrane. Resultados. La enfermedad renal crónica (ERC) preexistente en pacientes con SARS-CoV-2 varió de 1 a 38% y la lesión renal aguda (LRA), de 2.9 a 86.4%. El pronóstico de la infección fue peor en pacientes con ERC y en aquellos con reserva renal remanente (RRR) intacta que desarrollaron LRA. El riesgo de muerte fue mayor (riesgo relativo combinado = 1.49; IC95%: 1.09-2.04) en pacientes infectados por SARS-CoV-2 con ERC preexistente. Los mar­cadores de RRR mostraron alteraciones en pacientes con SARS-CoV-2 graves y fatales; el marcador más utilizado fue la creatinina sérica. Conclusiones. La evidencia científica muestra la relevancia de la evaluación y monitoreo perma­nente de la RRR en pacientes hospitalizados por SARS-CoV-2 para mejorar el pronóstico de aquellos con ERC preexistente, así como de aquellos sin ERC que desarrollan LRA.

Metabolic syndrome (MS) with mixed dyslipidemia and prostate cancer (PC) are relevant health problems among Mexican men. However, there is no information regarding the association between MS and PC for this population.To evaluate this association in a population case-control study in Mexico City.We analyzed the information from 394 incident PC-cases and 793 population age-matched (± 5 years) controls, identified in Mexico City (2011-2014). For cases, Gleason score at diagnosis was available. We defined MS history based on the self-report of hypertension, hypercholesterolemia, hypertriglyceridemia, and diabetes; obesity was evaluated using weight-change trajectories throughout life. In addition, the four MS-typologies described for Mexican population were used. The association between MS with PC and histological PC differentiation was evaluated using independent multivariate logistic regression models.MS history was associated with a high PC probability (OR 1.94; 95% CI 1.37-2.75). Lipid alterations, arterial hypertension, and a marked weight increase throughout life were associated with increased PC probability; however, only the marked weight increase was associated with more poorly differentiated PC (Gleason ≥8) (OR 2.79; 95% CI 1.50-5.17).Like other populations, in this Mexican study, MS and some of its components were identified as potential PC risk factors. MS-lipid alteration typology seems to be relevant; however, the novelty of this approach together with the retrospective nature of this study, indicate that a prospective evaluation of the MS typologies and PC association must be performed.

This study examined the association between intestinal lactobacilli and obesity dependent on dietary patterns in children. A cross-sectional study was conducted including 1111 children, 6-12 years old. Obesity was determined according to the WHO cut-off points. Diet information from a Food Frequency Questionnaire identified three dietary patterns. Lactobacillus sp. were determined by a real-time polymerase chain reaction (PCR). The consumption of complex carbohydrates and a high abundance of L. paracasei were associated with a lower risk of obesity (0.35, Confidence Interval 95% 0.19-0.65). The same happened with a medium consumption of fats and a medium abundance of L. paracasei (0.43, CI95% 0.24-0.78). In contrast, an increased risk of obesity is observed with a medium and high consumption of simple carbohydrates (2.37, CI95% 1.29-4.34 and 2.52, CI95% 1.36-4.66, respectively, p-trend

Background Mexico City has air, water and food pollution problems; however, human exposure to cadmium and its sources have not been described. Objectives To determine the blood cadmium (BCd) level and its main exposure sources among males aged 40 years or older living in different areas of Mexico City. Methods After receiving informed consent, we interviewed 702 males aged ≥40 years to collect data on their sociodemographic characteristics, lifetime occupation, smoking history, and dietary habits, using a validated questionnaire. The BCd level (μg/L) was determined by atomic absorption spectrophotometry. Results The BCd mean level ± SD was 2.61 ± 0.82 μg/L, and 20% of men reported a potential cadmium occupational exposure. After adjusting for age and other potential confounders, the main determinants of the BCd level were the current smoking status at interview, with low (β≤8.5packs/year vs. non-smoker = 0.46; 95% CI: 0.28–0.64 μg/L; p 8.5 packs/year vs. non-smoker = 0.71; 95% CI: 0.56–0.87 μg/L; p 1–3servings/month vs. No = 0.14, 95% CI: 0.01–0.26 μg/L; p Conclusions The BCd levels observed in this population are high and only similar to those observed in workers from a sanitary landfill area in Southern Thailand. Potential environmental Cd exposure sources, such as industrial activity and previous land use, in the West and Center areas of the city should be explored in detail, especially in vulnerable population groups, such as children.

Background Eating habits in children and adolescents are influenced by multiple determinants, which include socioeconomic and home environmental factors. Objective To characterize the dietary patterns in Mexican children and adolescents and to assess its association with socioeconomic and home environmental factors. Methods A cross-sectional study was conducted in 878 children and adolescents aged 5–15 years, unrelated, selected randomly from Morelos Sports Unit at north of Mexico City. Dietary, anthropometric, family, and socioeconomic information was obtained from each participant. Dietary patterns were identified through cluster analysis. The association between dietary patterns with socioeconomic and home environmental factors was assessed by a multivariate multinomial logistic regression model. Results Three major dietary patterns were identified: diverse dietary pattern (D), high fat dietary pattern (HF), and high sugar dietary pattern (HS). 87% of the participants followed the HF or HS dietary patterns (36% & 51%, respectively). Mother's occupation and the child's screen time was associated with a significant likelihood of following a HF and HS dietary patterns. Conclusion A high percentage of children and adolescents reported following a HS or HF dietary pattern, which in turn were associated with socioeconomic and home environmental factors. These results suggests priority groups for prevention and control actions.

In Mexico, 3 of 10 children are overweight. Fructose intake and relative abundance (RA) of Lactobacillus reuteri (L. reuteri) in the intestinal microbiota are associated with obesity and diabetes in adults, but studies in children are limited. This study evaluates the association between fructose intake and L. reuteri RA with adiposity and cardiometabolic risk markers in Mexican children dietary information, microbiota profiles, adiposity indicators (Body Mass Index, BMI and Waste Circumference, WC), and cardiometabolic markers were analyzed in 1087 children aged 6&ndash, 12 years. Linear regression and path analysis models were used. High-tertile fructose intake and L. reuteri RA were positively associated with BMI (&beta, Tertil 3 vs. Tertil 1 = 0.24 (95% CI, 0.04, 0.44) and &beta, T3 vs. T1 = 0.52 (95% CI, 0.32, 0.72)) and WC (&beta, T3 vs. T1 = 2.40 (95% CI, 0.93, 3.83) and &beta, T3 vs. T1 = 3.40 (95% CI, 1.95, 4.90)), respectively. Also, these factors mediated by adiposity were positively correlated with high triglycerides and insulin concentrations and HOMA-IR (p &le, 0.03) and negatively associated with HDL-C concentration (p &lt, 0.01). High-tertile fructose intake and L. reuteri RA were directly associated with adiposity and indirectly associated though adiposity with metabolic disorders in children. In conclusion, fructose intake and L. reuteri RA were directly associated with adiposity and indirectly associated with metabolic disorders in children, mediated by adiposity.

There has been substantial interest in phytoestrogens, because of their potential effect in reducing cancer and heart disease risk. Measuring concentrations of phytoestrogens in urine is an alternative method for conducting epidemiological studies. Our objective was to evaluate the urinary excretion of phytoestrogens as biomarkers for dietary phytoestrogen intake in Mexican women. Participants were 100 healthy women from 25 to 80 years of age. A food frequency questionnaire (FFQ) and a 24 h recall were used to estimate habitual and recent intakes of isoflavones, lignans, flavonols, coumestrol, resveratrol, naringenin, and luteolin. Urinary concentrations were measured by liquid chromatography (HPLC) coupled to mass spectrometry (MS) using the electrospray ionization interface (ESI) and diode array detector (DAD) (HPLC-DAD-ESI-MS). Spearman correlation coefficients were used to evaluate associations between dietary intake and urine concentrations. The habitual consumption (FFQ) of total phytoestrogens was 37.56 mg/day. In urine, the higher compounds were naringenin (60.1 µg/L) and enterolactone (41.7 µg/L). Recent intakes (24 h recall) of isoflavones (r = 0.460, p < 0.001), lignans (r = 0.550, p < 0.0001), flavonoids (r = 0.240, p < 0.05), and total phytoestrogens (r = 0.410, p < 0.001) were correlated to their urinary levels. Total phytoestrogen intakes estimated by the FFQ showed higher correlations to urinary levels (r = 0.730, p < 0.0001). Urinary phytoestrogens may be useful as biomarkers of phytoestrogen intake, and as a tool for evaluating the relationship of intake and disease risk in Mexican women.

Recent evidence suggests that a pro-inflammatory diet could be associated with prostate cancer (PC) risk. To evaluate the association between dietary inflammatory index (DII) and PC risk as well as aggressiveness, we conducted a case–control study in Mexico City. Cases were 394 individuals with incident, histologically confirmed PC, who were matched by age (±5 years) with 794 population controls. Dietary information was obtained through a semi-quantitative FFQ with a 3-year frame of reference before diagnosis, for cases, or interview, for controls. On the basis of twenty-eight food parameters, we estimated the energy-adjusted DII (E-DII). According to the Gleason score at diagnosis, PC cases were categorised as high (≥8), moderate (=7) and low (≤6) PC risk. Independent, unconditional logistic regression models adjusted for potential confounders were used to estimate PC risk and PC aggressiveness. There were no significant associations between overall PC risk and E-DII (OR3rd v. 1st tertile 1·18; 95 % CI 0·85, 1·63; P=0·33) or among men with high-risk PC (Gleason≥8) (OR 1·46; 95 % CI 0·88, 2·42; P=0·14). These results do not support the hypothesis that a pro-inflammatory diet is related to PC risk and PC aggressiveness. However, further studies with larger sample sizes, with sufficient statistical power and of varying designs should be conducted to address this hypothesis.

Background Phthalates, ubiquitous environmental pollutants that may disturb the endocrine system, are used primarily as plasticizers of polyvinyl chloride and as additives in consumer and personal care products. Objectives In this study, we examined the association between urinary concentrations of nine phthalate metabolites and breast cancer (BC) in Mexican women. Methods We age-matched 233 BC cases to 221 women residing in northern Mexico. Sociodemographic and reproductive characteristics were obtained by direct interviews. Phthalates were determined in urine samples (collected pretreatment from the cases) by isotope dilution/high-performance liquid chromatography coupled to tandem mass spectrometry. Results Phthalate metabolites were detected in at least 82% of women. The geometric mean concentrations of monoethyl phthalate (MEP) were higher in cases than in controls (169.58 vs. 106.78 μg/g creatinine). Controls showed significantly higher concentrations of mono-n-butyl phthalate, mono(2-ethyl-5-oxohexyl) phthalate, and mono(3-carboxypropyl) phthalate (MCPP) than did the cases. After adjusting for risk factors and other phthalates, MEP urinary concentrations were positively associated with BC [odds ratio (OR), highest vs. lowest tertile = 2.20; 95% confidence interval (CI), 1.33–3.63; p for trend < 0.01]. This association became stronger when estimated for premenopausal women (OR, highest vs. lowest tertile = 4.13; 95% CI, 1.60–10.70; p for trend < 0.01). In contrast, we observed significant negative associations for monobenzyl phthalate (MBzP) and MCPP. Conclusions We show for the first time that exposure to diethyl phthalate, the parent compound of MEP, may be associated with increased risk of BC, whereas exposure to the parent phthalates of MBzP and MCPP might be negatively associated. These findings require confirmation.

N-nitroso compounds (NOC) are potent animal carcinogens and potential human carcinogens. The primary source of exposure for most individuals may be endogenous formation, a process that can be inhibited by dietary polyphenols. To estimate the risk of gastric cancer (GC) in relation to the individual and combined consumption of polyphenols and NOC precursors (nitrate and nitrite), a population-based case-control study was carried out in Mexico City from 2004 to 2005 including 257 histologically confirmed GC cases and 478 controls. Intake of polyphenols, nitrate and nitrite were estimated using a food frequency questionnaire. High intakes of cinnamic acids, secoisolariciresinol and coumestrol were associated with an approximately 50% reduction in GC risk. A high intake of total nitrite as well as nitrate and nitrite from animal sources doubled the GC risk. Odds ratios around 2-fold were observed among individuals with both low intake of cinnamic acids, secoisolariciresinol or coumestrol and high intake of animal-derived nitrate or nitrite, compared to high intake of the polyphenols and low animal nitrate or nitrite intake, respectively. Results were similar for both the intestinal and diffuse types of GC. Our results show, for the first time, a protective effect for GC because of higher intake of cinnamic acids, secoisolariciresinol and coumestrol, and suggest that these polyphenols reduce GC risk through inhibition of endogenous nitrosation. The main sources of these polyphenols were pears, mangos and beans for cinnamic acids; beans, carrots and squash for secoisolariciresinol and legumes for coumestrol.

ObjectiveTo perform an evaluation of selected phytochemicals intake and breast cancer (BC) risk in Mexican women.DesignWe conducted hospital-based case–control study.SettingMexico City between 1994 and 1996.SubjectsA total of 141 histologically confirmed BC cases were age-matched (±3 years) to an equal number of hospital controls. The reproductive history of each woman was obtained by direct interview. The dietary consumption of flavonols, flavones, flavan-3-ols, cinnamic acid, lariciresinol, pinoresinol, secoisolariciresinol, matairesinol and coumestrol was obtained by means of a validated FFQ.ResultsAmong postmenopausal women, high dietary intake of flavonols and flavones was associated with a significant reduction of BC risk (highv. low tertile: OR = 0·21, 95 % CI 0·07, 0·60,Pfor trend = 0·004 and OR = 0·29, 95 % CI 0·10, 0·82,Pfor trend = 0·025, respectively); consumption of lignans (lariciresinol and pinoresinol) showed a similar effect, but only among premenopausal women (highv. low tertile: OR = 0·32, 95 % CI 0·10, 0·99,Pfor trend = 0·051 and OR = 0·19, 95 % CI 0·06, 0·62,Pfor trend = 0·006, respectively).ConclusionsOur results support a protective role of specific dietary phytochemicals in BC risk by menopausal status, independent of other reproductive factors.

Background Civilization has produced lifestyle changes; currently, people ingest more calories than are expended, resulting in obesity. This study assessed the association between dietary habits, physical activities, and sedentary behaviors and the risk of obesity in schoolchildren in Mexico City. Methods Of 1,441 children (6–12 years old) screened in elementary schools, 202 obese (BMI ≥95th pc) and 200 normal-weight children (BMI 25th- 75th pc), as defined by the 2000 CDC criteria, were included in a case–control study. The children’s eating, physical activity and sedentary lifestyle habits were recorded using validated questionnaires. The quantity and quality of the foods were obtained, and the energy that was expended was transformed into METs. Sedentary behavior was assessed in hours. Logistic regression models were used to determine the risks of certain habits and their association with obesity. Results Obese children ingested around of 270 Kcal less than eutrophic children. However, compared with the eutrophic children, obese children had significantly worse lifestyle habits; the children with healthy dietary habits (eating breakfast at home, bringing a school lunch, and not bringing money to purchase food) had a lower risk of obesity (OR 0.59, CI 0.46; 0.75). The quality of the eaten food was associated with a risk of obesity. Consuming fruit demonstrated an inverse association with risk of obesity (p Trend = 0.01); consumption of sweetened beverages (p Trend

A hospital-based case-control study was carried out between 1994 and 1996 to evaluate the risk of gastric cancer (GC) according to Helicobacter pylori-CagA (+) seropositivity, nitrite and ascorbic acid intake. Three geographical areas of Mexico were selected on the basis of their contrasting dietary patterns and H. pylori seroprevalence. Nitrite and ascorbic acid consumption were estimated by interview among 211 cases and 454 matched controls. Serum antibodies against IgG H. pylori and CagA were detected by immunosorbent assays. The adjusted risk for GC was significantly higher among CagA+ subjects compared with those that were CagA negative (Odds Ratio (OR) ¼ 2.04 95% Confidence Interval (CI) 1.37–3.02 P for trend P < 0:001), this effect remained significant among diffuse GC cases (OR 2.05 95% CI 1.25-3-36). No significant effects due to nitrite and ascorbic consumption or interactions of these nutrients with CagA seropositivity were detected. Seropositivity to H. pylori CagA+ strains may be an independent factor for diffuse GC in Mexico. 2004 Elsevier Ltd. All rights reserved.

Resistance to antibiotics is common in patients with Helicobacter pylori infection in more than one anatomic stomach site. We assessed whether the antibiotic resistance varies according to virulence factors of the bacteria as well as to the age and gender of individuals infected in two anatomic sites.H. pylori strains were isolated from an antral and corpus biopsy from 90 patients with gastric ambulatory who had not received any previous therapy. Susceptibility to metronidazole and clarithromycin was assessed by E-test, and vacA and cagA genotypes were determined by polymerase chain reaction.Dual resistance to metronidazole and clarithromycin was 3.3% in antrum and 4.4% in the corpus; heteroresistance was 19% and 5.5% for metronidazole and clarithromycin, respectively. Clarithromycin resistance significantly increased with age. Women showed a twofold increased risk for metronidazole-resistant strains in antrum (odds ratio = 2.85, 95% confidence interval 1.09 to 7.42). Virulence factors were not associated with antimicrobial resistance.Prevalence of resistance to clarithromycin may be increasing in this country. Antimicrobial susceptibility tests from different biopsy sites deserve attention.

Objetivo. Evaluar la reproducibilidad y validez de la ingestión de folato (IF), estimada a partir de un cuestionario de frecuencia de consumo (CFC), considerando el factor de retención (FR) correspondiente al método de preparación empleado. Material y métodos. Al inicio del estudio se entrevistó a 497 adultos sanos; un año después se realizó una segunda entrevista a una muestra de 100 individuos seleccionados aleatoriamente, que no hubieran modificado su dieta durante el año previo; adicionalmente, para evaluar la validez de la IF, mediante radioinmunoensayo, se determinaron los niveles de folato sérico (FS). Resultados. La reproducibilidad de la IF fue de 0.36 y 0.34 para el folato sin y con FR, respectivamente. Se observó una correlación significativa entre la IF y el FS de 0.18 con FR y 0.21 sin FR (p0.05, respectivamente). Conclusiones. Incorporar el FR en las estimaciones de la IF no mejora la reproducibilidad ni la validez de las mismas.

To evaluate the reproducibility and validity of folate intake (FI) estimated from a food frequency questionnaire (FFQ), taking into account the retention factor (RF) associated with meal preparation processes.A total of 497 healthy adult participants were interviewed with a FFQ. A second interview was performed one year later of a sample of 100 randomly selected individuals who had not modified their diet during the previous year. In addition,serum folate (SF) concentrations were measured by radioimmunoassay to evaluate the validity of FI.Reproducibility of IF was 0.36 and 0.34 for folate without FR and with FR, respectively. SF concentration significantly correlated with FI (0.18 with RF; 0.21 without RF, p0.05).Incorporating the folate RF in estimates of FI does not improve the reproducibility and validity of those estimates.

Using the Bayley test, the mental and psychomotor development in a cohort of 253 children were evaluated. Maternal dietary intake of vitamin B12 and folate was assessed from a semiquantitative questionnaire administered during the first trimester of pregnancy. Maternal genotypes of MTHFR (677C>T and 1298A>C), were ascertained by PCR-RFLP. The 677T and 1298C variant alleles were present in 59% and 10% of participants, respectively. A dietary deficiency of vitamin B12 was negatively associated with mental development (β = −1.6; 95% CI = −2.8 to −0.3). In contrast, dietary intake of folate (< 400 mg/day) reduced the mental development index only among children of mothers who were carriers of the TT genotype (β = −1.8; 95% CI = −3.6 to −0.04; P for interaction = 0.07). Vitamin B12 and folate supplementation during pregnancy could have a favorable impact on the mental development of children during their first year of life, mainly in populations that are genetically susceptible.

Mundialmente el cancer de mama (CM) es la primera causa de muerte por tumores malignos entre las mujeres. OBJETIVO: Revisar los estudios epidemiologicos mas relevantes sobre dieta y CM en America Latina y el Caribe (ALC). MATERIAL Y METODOS: La busqueda sistematica realizada en Mexico en el lapso de junio a noviembre del ano 2008 en PubMed-Medline, Scielo y Google, identifico 27 estudios en ALC, que evaluaron la asociacion entre dieta y CM. RESULTADOS: La investigacion sugiere un efecto protector de ciertos vegetales, frutas, pescado, fibra, vitamina B12 y folato, varios fitoestrogenos, licopeno y grasas poliinsaturadas, asi como un riesgo potencial por la elevada ingestion calorica, consumo de carnes rojas, procesadas y procesos de coccion, leche y productos lacteos, grasas saturadas y sacarosa. CONCLUSIONES: El impacto del consumo de alimentos y nutrimentos especificos sobre la incidencia del CM no es concluyente, por lo cual se requieren mas estudios especificos.

Breast cancer (BC) is the primary cause of death from malignant tumors in women worldwide.Review epidemiological studies from the Latin-America and Caribbean (LAC) region.A systematic search, carried out during June-November 2008 in Mexico of PubMed/Medline, Scielo, and Google identified 27 epidemiological studies in LAC that evaluated associations between diet and BC.The research on diet and BC suggests the protective effect of certain fruits, vegetables, fish, fiber, vitamin B(12), folate, various phytoestrogens, lycopene, and polyunsaturated fats; as well as the potential risk associated with elevated caloric consumption, consumption of red meat and processed meats, certain meat cooking techniques, milk and some other dairy products, saturated fat, and sucrose.The impact of specific foods and nutrients on breast cancer incidence is inconclusive. Further research is needed on this topic.

Objective To assess gastric cancer survival in relation to dietary intake of methyl donors and the methylenetetrahydrofolate reductase 677C > T (MTHFR 677C > T) polymorphism. Methods A prospective cohort of 257 incidental, histologically confirmed gastric cancer cases was assembled in January 2004 and followed until June 2006. Patients were recruited from the main oncology and/or gastroenterology units in Mexico City and were queried regarding their sociodemographic information, clinical history, and dietary habits 3 y before the onset of their symptoms. The intake of methyl donors was estimated with a food-frequency questionnaire and the MTHFR 677C > T polymorphisms were determined by polymerase chain reaction/restriction fragment length polymorphism analysis. Cox's multivariate regression models were used to estimate the mortality risk of gastric cancer. Results MTHFR 677TT carriers with low folate and vitamin B12 intakes had the lowest survival rate in cases of gastric cancer. High intakes of folate and vitamin B12 before diagnosis was associated with decreased gastric cancer mortality risk in susceptible MTHFR 677TT carriers (mortality risk for folate 0.14, 95% confidence interval 0.04–0.46, P for trend = 0.001; mortality risk for vitamin B12 0.23, 95% confidence interval 0.08–0.66, P for trend = 0.008). Conclusion Folate and related B vitamins may be used as an intervention strategy to improve the survival outcome of gastric cancer.

DNA methylation is an important epigenetic process for transcriptional control of human genome including those genes involved in cancer initiation and progression. Clinical studies have suggested that biological explanation to the protective effect of some nutrients could be linked with the DNA methylation. Folate is a primary methyl donor nutrient; it has been shown to play a key role in DNA methylation, repair and synthesis, by acting as co-factors and/or substrates in this metabolic pathway. Likewise, activity of a key enzyme, the methylenetetrahydrofolate reductase (MTHFR) has also been shown to influence DNA methylation. Overall, these findings support the notion that dietary intake as well as genetic factors play a role in one-carbon metabolism. This study is to evaluate the dietary intake of nutrients involved in one-carbon metabolism and the genotype of MTHFR 677 C > T with respect to GC risk. We carried out in January 2004 a population-based case–control study in the metropolitan area of Mexico City. A total of 248 histological confirmed GC patients were recruited from nine tertiary hospitals, along with 478 age and sex-matched controls. Nutrient intake was estimated from food frequency questionnaire; the MTHFR 677C > T genotype was determined by PCR-RFLP analysis. A significant reduction in diffuse GC risk was observed for MTHFR 677 TT genotype among individuals with high consumption of folate (OR = 0.23; 95% CI 0.06–0.84), choline (OR = 0.55; 95% CI 0.33–0.9) and Vitamin B6 (OR = 0.59; 95% CI 0.36–0.96) compared to MTHFR 677 CC + CT carriers. Among subjects with low consumption of methionine, a reduced risk of diffuse GC was also detected (OR = 0.40; 95% CI 0.16–0.97). In contrast, carriers of the MTHFR 677 TT genotype with a low consumption of folate had a significant increased risk of intestinal GC (OR = 1.88 95% CI 1.02–3.47). A folate–MTHFR 677 C > T interaction in the borderline of significance (P = 0.055) was detected. It is probable that GC prevention requires dietary recommendations according to the individual genotype; nevertheless, the available information to this respect is still very limited.

OBJECTIVE: To asses the association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA) according to the maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677 C>T and 1298 A>C). MATERIAL AND METHODS: We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. RESULTS: Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95% CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95% CI: 1.1, 26.6). CONCLUSIONS: Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins.

"Objective. Identify the content of selected phytochemi-cals (PHYs) in Mexican foods and evaluate the reliability ofa food frequency questionnaire (FFQ) in assessing PHYsintake among Mexican women. Material and Methods.Values for PHYs content were obtained from four differentdata sets. PHYs intake was assessed in 50 women of repro-ductive age enrolled in a longitudinal cohort study. Valueswere obtained from a FFQ administered twice, one yearapart in order to evaluate its reliability. Selected PHYs in-cluded flavonol (FOL), flavones (FES), flavanol (FAL), secoiso-lariciresinol (SE), matairesinol (MA), lariciresinol (LA),pinoresinol (PI), cynamic acid (CA) and coumestrol (CU).Results. Daily PHYs intake ranged from 1.3 µg ± 0.9 for MAto 116.3 ± 43.8 mg for CA. The adjusted correlation coeffi-cients ranged from 0.17 for FAL to 0.47 for LA. Pinto beans,oranges, hot sauce, broccoli, apples and onions were the mainsources of the selected PHYs daily intake. Discussion. Theresults of this study contribute to our understanding of theconsumption of PHYs in the Mexican diet, and would helpevaluate their potential health impact."

This study investigated whether methylenetetrahydrofolate reductase MTHFR 677C>T polymorphism modified gastric cancer (GC) risk independently as well as in combination with folate intake and alcohol consumption. A hospital-based case-control study of 201 cases and 427 controls was conducted in three geographical areas of Mexico, between 1994 and 1996. The MTHFR 677T allele frequency was 51.0% in cases compared with 45.3% in controls. After controlling for dietary sources of folate, alcohol intake and other selected variables, a significant increase in GC risk was found among carriers of the 677TT genotype compared with those with the 677CC genotype (odds ratio (OR) 1.62, 95% confidence interval (CI) 1.00-2.59), with a significant trend (P = 0.048). There were no significant interactions between the MTHFR polymorphism and consumption of folate and alcohol. Our results suggest that the high prevalence of MTHFR 677T allele may be a contributor to the high rate of morbidity and mortality in GC in Mexico.

Benign breast disease (BBD) is common in women in the reproductive age group. The results of epidemiological studies that have examined the relationship between diet and BBD are controversial and scarce. The aim of the present study was to identify and evaluate the impact of dietary and reproductive risk factors in the development of BBD in Mexican women. Between 1994 and 1996, 121 women with BBD and 121 age-matched (+/- 3 yr) clinical controls with non-breast-related diseases were identified. The study population was directly interviewed about their reproductive history, and a semiquantitative food frequency questionnaire was used to obtain dietary information. The population was originally identified as part of a hospital-based case-control study examining exposure to 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane and breast cancer. A significant reduction in the risk of BBD was observed when comparing the upper with the lower tertiles of consumption of citrus fruit [odds ratio (OR) = 0.43, 95% confidence interval (CI) = 0.21-0.88], non-citrus fruit (OR = 0.35, 95% CI = 0.16-0.76), diary products (OR = 0.36, 95% CI = 0.18-0.75), and food sources of lignans (OR = 0.48, 95% CI = 0.24-0.98). A marginally significant reduction in the risk of BBD associated with the consumption of vitamin B-12 (OR = 0.48, 95% CI = 0.23-1.02) was also observed. Our results add new information about the role of diet in the etiology of BBD.

This article analyzes food consumption in relation to levels of DDE (the principal metabolite of DDT) in the adipose tissue of 207 Mexican women residing in States with high and low exposure to DDT. Data on the women's dietary habits and childbearing history were obtained from a personal interview. Adipose tissue DDE levels were measured by gas-liquid chromatography and compared by analysis of variance (ANOVA) and multiple linear regression. Adipose tissue DDE levels increased significantly with age (p = 0.005) and residence in coastal areas (p = 0.002) and non-significantly with the consumption of onion, cauliflower, prickly pear, squash blossoms, sweet corn, broad beans, chili pepper sauce, ham, and fish. Even so, during breastfeeding there was a non-significant reduction in these levels. The findings suggest that certain foods serve as vehicles for DDE residues and confirm that breastfeeding is a mechanism for the elimination of this insecticide, which accumulates over the years in the human body.

ObjectiveTo assess the effect of Leisure‐time physical activity (LTPA) on cardiometabolic risk by nutritional status in Mexican children and adolescents.MethodsThis was a cross‐sectional study conducted with 1,309 participants aged between 5 and 17 years. Nutritional status was classified according to the BMI Z‐score by age and gender. A previously validated questionnaire was used to evaluate LTPA; a cardiometabolic risk score was calculated. Multiple linear regression analysis was performed to assess the effect of LTPA on cardiometabolic risk.ResultsAfter adjusting for risk factors, mild LTPA were positively associated with cardiometabolic risk score (βMild vs. Intense LTPA: 0.68; 95% CI: 0.18 to 1.18; pfor trend = 0.007). This association became stronger when estimated for overweight (β Mild vs. Intense LTPA: 1.24; 95% CI: 0.24 to 2.24; pfor trend = 0.015) and obese participants (β Mild vs. Intense LTPA: 1.02; 95% CI: 0.07 to 1.97; p for trend = 0.045).ConclusionMild LTPA was positively associated with cardiometabolic risk in overweight and obese children and adolescents. Given the emerging childhood obesity epidemic in Mexico, these results may be useful in the design of strategies and programs to increase physical activity levels in order to achieve better health.ResumoObjetivoAvaliar o efeito da prática de AFL sobre o risco cardiometabólico em crianças e adolescentes mexicanos de acordo com sua situação nutricional.MétodosEstudo transversal feito com 1.309 participantes de cinco a 17 anos. A situação nutricional foi classificada de acordo com o escore z de IMC por idade e sexo. Um questionário validado anteriormente foi usado para avaliar a AFL; foi calculado um escore de risco cardiometabólico. A análise de regressão linear múltipla foi feita para avaliar o efeito de AFL sobre o risco cardiometabólico.ResultadosApós o ajuste de acordo com os fatores de risco, a AFL leve foi positivamente associada ao escore de risco cardiometabólico (βAFL Leve x Intensa: 0,68; IC 95%: 0,18 a 1,18; p para tendência = 0,007). Essa associação foi mais intensa quando estimada para participantes acima do peso (βAFL Leve x Intensa: 1,24; IC 95%: 0,24 a 2,24; p para tendência = 0,015) e obesos (βAFL Leve x Intensa: 1,02; IC 95%: 0,07 a 1,97; p para tendência = 0,045).ConclusãoA AFL leve foi positivamente associada ao escore de risco cardiometabólico em crianças e adolescentes acima do peso e obesos. Considerando a epidemia de obesidade infantil emergente no México, esses resultados poderão ser úteis na elaboração de estratégias e programas para aumentar os níveis de atividade física a fim de obter uma saúde melhor.