Tea consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling (StoP) Project consortium.

BACKGROUND: Evidence from epidemiological studies on the role of tea drinking in gastric cancer risk remains inconsistent. We aimed to investigate and quantify the relationship between tea consumption and gastric cancer in the Stomach cancer Pooling (StoP) Project consortium. METHODS: A total of 9438 cases and 20,451 controls from 22 studies worldwide were included. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of gastric cancer for regular versus non-regular tea drinkers were estimated by one and two-stage modelling analyses, including terms for sex, age and the main recognised risk factors for gastric cancer. RESULTS: Compared to non-regular drinkers, the estimated adjusted pooled OR for regular tea drinkers was 0.91 (95% CI: 0.85-0.97). When the amount of tea consumed was considered, the OR for consumption of 1-2 cups/day was 1.01 (95% CI: 0.94-1.09) and for >3 cups/day was 0.91 (95% CI: 0.80-1.03). Stronger inverse associations emerged among regular drinkers in China and Japan (OR: 0.67, 95% CI: 0.49-0.91) where green tea is consumed, in subjects with H. pylori infection (OR: 0.68, 95% CI: 0.58-0.80), and for gastric cardia cancer (OR: 0.64, 95% CI: 0.49-0.84). CONCLUSION: Our results indicate a weak inverse association between tea consumption and gastric cancer.

Allium vegetables intake and the risk of gastric cancer in the Stomach cancer Pooling (StoP) Project.

BACKGROUND: The role of allium vegetables on gastric cancer (GC) risk remains unclear. METHODS: We evaluated whether higher intakes of allium vegetables reduce GC risk using individual participant data from 17 studies participating in the "Stomach cancer Pooling (StoP) Project", including 6097 GC cases and 13,017 controls. Study-specific odds ratios (ORs) were pooled using a two-stage modelling approach. RESULTS: Total allium vegetables intake was inversely associated with GC risk. The pooled OR for the highest versus the lowest study-specific tertile of consumption was 0.71 (95% confidence interval, CI, 0.56-0.90), with substantial heterogeneity across studies (I2 > 50%). Pooled ORs for high versus low consumption were 0.69 (95% CI, 0.55-0.86) for onions and 0.83 (95% CI, 0.75-0.93) for garlic. The inverse association with allium vegetables was evident in Asian (OR 0.50, 95% CI, 0.29-0.86) but not European (OR 0.96, 95% CI, 0.81-1.13) and American (OR 0.66, 95% CI, 0.39-1.11) studies. Results were consistent across all other strata. CONCLUSIONS: In a worldwide consortium of epidemiological studies, we found an inverse association between allium vegetables and GC, with a stronger association seen in Asian studies. The heterogeneity of results across geographic regions and possible residual confounding suggest caution in results interpretation.

Towards a unified curriculum system based on a public health holistic approach. Renovation of the academic programs at the School of Public Health of Mexico.

Public health training cannot be practiced in isolation, but rather within the framework of substantive conceptual visions, the organizational structure and teaching culture in a broad sense. The School of Public Health of Mexico (ESPM), in the mist of its 100th anniversary, is implementing an educational restructure with the guidance of conceptual and ethical principles. The restructure of the academic pro-grams will follow a constructivist pedagogical model, based on renewed institutional practices that integrates research, teaching and community outreach, making for truly transfor-mative learning. The new design of the whole structure of its academic programs has the objetive of making them flexible, less technical-based but more practical, and a within an uni-fied curricular system that articulates and allows continuity between master's degrees and doctorates programs. In the new structure, the curriculum will have a common core for all the academic programs, emerging from the study of the essential bases of public health, human rights, including gender and social perspectives, principles of global health, ethics of public health practice, environmental and animal health inferences and community outreach in the form of social retribution. The Institute's research groups will be the functional units for investigation and teaching, thus students will be integrated into these at an early stage, under the guidance of a tutor. In this context, the requirements for a comprehensive, unifying and at the same time flexible cur-riculum will support training of Public Health with a holistic approach. The current programs were analyzed including the review of their courses, regarding the pertinence of their contents and proposed competencies. We present herein a description of these observations, and propose a new com-mon core (conceptual-operative) with compulsory courses as the base for all programs. The participation of all academic bodies in reviewing the proposed new common core, as well as the syllabus and courses, identified those that are essential in each program's study concentration area, is indicated.

Coffee consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling Project consortium.

OBJECTIVE: This study aimed to evaluate and quantify the relationship between coffee and gastric cancer using a uniquely large dataset from an international consortium of observational studies on gastric cancer, including data from 18 studies, for a total of 8198 cases and 21 419 controls. METHODS: A two-stage approach was used to obtain the pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for coffee drinkers versus never or rare drinkers. A one-stage logistic mixed-effects model with a random intercept for each study was used to estimate the dose-response relationship. Estimates were adjusted for sex, age and the main recognized risk factors for gastric cancer. RESULTS: Compared to never or rare coffee drinkers, the estimated pooled OR for coffee drinkers was 1.03 (95% CI, 0.94-1.13). When the amount of coffee intake was considered, the pooled ORs were 0.91 (95% CI, 0.81-1.03) for drinkers of 1-2 cups per day, 0.95 (95% CI, 0.82-1.10) for 3-4 cups, and 0.95 (95% CI, 0.79-1.15) for five or more cups. An OR of 1.20 (95% CI, 0.91-1.58) was found for heavy coffee drinkers (seven or more cups of caffeinated coffee per day). A positive association emerged for high coffee intake (five or more cups per day) for gastric cardia cancer only. CONCLUSIONS: These findings better quantify the previously available evidence of the absence of a relevant association between coffee consumption and gastric cancer.

Intervenciones no farmacológicas para reducir síntomas depresivos en mujeres con cáncer de mama / Non-pharmacological interventions to reduce depressive symptoms in women with breast cancer

Resumen: Objetivo: Describir y discutir los resultados de las intervenciones no farmacológicas (INF) adyuvantes en el tratamiento de los síntomas depresivos entre mujeres con cáncer de mama (CaMa). Material y métodos: Se realizó una revisión sistemática sobre INF, aplicadas a pacientes con cáncer y síntomas depresivos en siete bases de datos. La revisión se limitó del 1 de enero de 2006 al 31 de diciembre de 2017 y a los idiomas inglés, español y portugués. Los descriptores médicos empleados fueron "breast neoplasm" y "depression". Resultados: Existen diversas INF que pueden estimular principalmente las dimensiones físicas o psicosociales. En este artículo se propone una clasificación basada en nueve estrategias terapéuticas identificadas, entre las que sobresalen el ejercicio, la psicoterapia y el yoga con meditación. Conclusiones: Con base en la evidencia disponible, se concluye que la psicoterapia y yoga con meditación reducen los síntomas depresivos en pacientes con CaMa. Se requiere mayor investigación para determinar la magnitud de la reducción de los síntomas depresivos, de acuerdo con su gravedad, presencia de comorbilidades y diversidad de INF.

Abstract: Objective: To describe and discuss the results of non-pharmacological interventions (NPI) adjuvants in the treatment of depressive symptoms among women with breast cancer (BC). Materials and methods: A systematic review on NPI was performed, which was applied to patients with cancer and depressive symptoms in seven databases. The review was limited from January 1, 2006 to December 31, 2017 and to English, Spanish and Portuguese languages. The medical descriptors used were "breast neoplasm" and "depression". Results: There are several NPI that are able stimulate the physical or psychosocial dimensions. In this article we propose a classification based on nine identified therapeutic strategies, among which exercise, psychotherapy and yoga with meditation stand out. Conclusions: Based on the available evidence, we concluded that psychotherapy and yoga with meditation reduce depressive symptoms in patients with CaMa. More research is needed to determine the magnitude of the reduction of depressive symptoms, according to their severity, presence of comorbidities and diversity of INF.

[Non-pharmacological interventions to reduce depressive symptoms in women with breast cancer]. / Intervenciones no farmacológicas para reducir síntomas depresivos en mujeres con cáncer de mama.

OBJECTIVE: To describe and discuss the results of non-pharmacological interventions (NPI) adjuvants in the treatment of depressive symptoms among women with breast cancer (BC). MATERIALS AND METHODS: A systematic review on NPI was performed, which was applied to patients with cancer and depressive symptoms in seven databases. The review was limited from January 1, 2006 to December 31, 2017 and to English, Spanish and Portuguese languages. The medical descriptors used were "breast neoplasm" and "depression". RESULTS: There are several NPI that are able stimulate the physical or psychosocial dimensions. In this article we propose a classification based on nine identified therapeutic strategies, among which exercise, psychotherapy and yoga with meditation stand out. CONCLUSIONS: Based on the available evidence, we concluded that psychotherapy and yoga with meditation reduce depressive symptoms in patients with CaMa. More research is needed to determine the magnitude of the reduction of depressive symptoms, according to their severity, presence of comorbidities and diversity of INF.

OBJECTIVE: Describir y discutir los resultados de las intervenciones no farmacológicas (INF) adyuvantes en el tratamiento de los síntomas depresivos entre mujeres con cáncer de mama (CaMa). MATERIALS AND METHODS: Se realizó una revisión sistemática sobre INF, aplicadas a pacientes con cáncer y síntomas depresivos en siete bases de datos. La revisión se limitó del 1 de enero de 2006 al 31 de diciembre de 2017 y a los idiomas inglés, español y portugués. Los descriptores médicos empleados fueron "breast neoplasm" y "depression". RESULTS: Existen diversas INF que pueden estimular principalmente las dimensiones físicas o psicosociales. En este artículo se propone una clasificación basada en nueve estrategias terapéuticas identificadas, entre las que sobresalen el ejercicio, la psicoterapia y el yoga con meditación. CONCLUSIONS: Con base en la evidencia disponible, se concluye que la psicoterapia y yoga con meditación reducen los síntomas depresivos en pacientes con CaMa. Se requiere mayor investigación para determinar la magnitud de la reducción de los síntomas depresivos, de acuerdo con su gravedad, presencia de comorbilidades y diversidad de INF.

Non-pharmacological therapies for depressive symptoms in breast cancer patients: Systematic review and meta-analysis of randomized clinical trials.

OBJECTIVE: Depressive symptoms are common comorbidities among breast cancer (BC) patients. Non-pharmacological therapies (NPTs) such as exercise and psychotherapy may reduce depressive symptoms; however, the evidence is inconclusive. The objective of this study is to evaluate if NPTs reduce depressive symptoms among BC patients. METHODS: A systematic review and meta-analysis of randomized clinical trials (RCTs) of NPTs for BC patients were performed. A literature search was conducted from eight databases in English, Portuguese and Spanish from 2006 to 2017. Inclusion criteria were: RCTs that evaluated depressive symptoms as a primary or secondary outcome that did not include pharmacological interventions and did include a non-intervened control group, with at least 30 participants in non-terminal BC stage with no current psychiatric illness. A meta-analysis for each NPT was performed with DerSimonian and Laird's method for the random effects model. Sensitivity analyses were conducted. Heterogeneity and publication bias were assessed. RESULTS: A total of 41 eligible RCTs were identified. Overall, NPTs significantly reduced depressive symptoms (Summary standardized mean difference (SMD) = -0.516; 95%CI: -0.814, -0.218; I2 = 96.2). Of the types of NPTs, psychotherapy significantly reduced depressive symptoms (Summary SMD = -0.819; 95% CI: -1.608, -0.030; I2 = 91.53). A significant difference emerged for Mindfulness (Summary SMD = -0.241; 95% CI: -0.412, -0.070; I2 = 28.6%) and yoga (Summary SMD = -0.305; 95% CI: -0.602, -0.007; I2 = 41.0%) when the heterogeneity was reduced. No evidence of publication bias was observed. CONCLUSIONS: Psychotherapy and mind-body therapies may reduce depressive symptoms in women with BC. Laughter and couples therapy warrant attention in future studies.

Dietary flavonoids improve urinary arsenic elimination among Mexican women.

Inorganic arsenic (iAs) exposure increases risk of several diseases, including cancer. Some nutrients such as flavonoids enhance glutathione activity, which in turn play a key role in iAs elimination. Our objective was to explore whether dietary non-soy flavonoids are associated with iAs metabolism. We hypothesized that the intake of flavonoids belonging to the following groups, flavan-3-ols, flavone, flavonol, flavanone, and anthocyanidin, is positively associated with urinary dimethylarsinic acid (DMA), which is the most soluble iAs metabolite excreted. We performed a cross-sectional study that included 1027 women living in an arsenic-contaminated area of northern Mexico. Flavonoid intake was estimated using a validated food frequency questionnaire. Concentration of urinary iAs and its metabolites (monomethylarsonic acid and DMA) were determined by high performance liquid chromatography ICP-MS. Results showed positive significant associations between DMA and the flavonoid groups flava-3-ols (ß= 0.0112) and flavones (ß= 0.0144), as well as the individual intake of apigenin (ß= 0.0115), luteolin (ß= 0.0138), and eriodictyol (ß= 0.0026). Our findings suggest that certain non-soy flavonoids may improve iAs elimination; however, there is still very limited information available regarding the consumption of flavonoids and iAs metabolism.

Phytoestrogen Concentrations in Human Urine as Biomarkers for Dietary Phytoestrogen Intake in Mexican Women.

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.

Maternal dietary intake of folate, vitamin B12 and MTHFR 677C>T genotype: their impact on newborn's anthropometric parameters.

In this study, we evaluated the effects of dietary intake of vitamin B12 and folate during pregnancy and their interactions with maternal polymorphism of MTHFR (677C>T; 1298A>C) on intrauterine development. Anthropometric parameters were obtained from 231 newborns that belong to a prospective birth cohort in Morelos, Mexico. Maternal dietary intake of vitamin B12 and folate was assessed using a semi-quantitative questionnaire administered during the first and third trimesters of the pregnancy. Maternal MTHFR 677C>T and 1298 A>C genotypes were determined by PCR-RFLP. The associations between deficient dietary intake of vitamin B12 (<2.0 µg/d) and folate (<400 µg/d) in the first and third trimesters and maternal polymorphisms of MTHFR on anthropometric parameters at birth were estimated using a multivariate linear regression model. During pregnancy, the deficient dietary intake was roughly 60 % for folate and 19 % for vitamin B12. Allelic frequencies of 677T and 1298C were 59 and 10 %, respectively. After adjusting for confounders, deficiency in maternal dietary intake of vitamin B12 (<2.0 µg/d) was associated with a significant reduction in length (ß ~ -2.4; 95 % CI -4.3; -0.6) and length-for-age at birth (ß ~ -1.2; 95 % CI -2.3; -0.1) among infants whose mothers were carriers of the 677TT genotype (p for interaction = 0.02). In contrast, no association was observed between deficiency in maternal dietary intake of folate (<400 µg/d) and any anthropometric parameter of newborns. These results suggest that supplementation with vitamin B12 during pregnancy could have a favorable impact on intrauterine fetal development mainly in populations that are genetically susceptible.

Maternal MTHFR 677C>T genotype and dietary intake of folate and vitamin B(12): their impact on child neurodevelopment.

Using the Bayley test, the mental and psychomotor development in a cohort of 253 children were evaluated. Maternal dietary intake of vitamin B(12) 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 B(12) was negatively associated with mental development (beta = -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 (beta = -1.8; 95% CI = -3.6 to -0.04; P for interaction = 0.07). Vitamin B(12) 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.

Dietary consumption of phytochemicals and breast cancer risk in Mexican women.

OBJECTIVE: To perform an evaluation of selected phytochemicals intake and breast cancer (BC) risk in Mexican women. DESIGN: We conducted hospital-based case-control study. SETTING: Mexico City between 1994 and 1996. SUBJECTS: A 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. RESULTS: Among postmenopausal women, high dietary intake of flavonols and flavones was associated with a significant reduction of BC risk (high v. low tertile: OR = 0.21, 95 % CI 0.07, 0.60, P for trend = 0.004 and OR = 0.29, 95 % CI 0.10, 0.82, P for trend = 0.025, respectively); consumption of lignans (lariciresinol and pinoresinol) showed a similar effect, but only among premenopausal women (high v. low tertile: OR = 0.32, 95 % CI 0.10, 0.99, P for trend = 0.051 and OR = 0.19, 95 % CI 0.06, 0.62, P for trend = 0.006, respectively). CONCLUSIONS: Our results support a protective role of specific dietary phytochemicals in BC risk by menopausal status, independent of other reproductive factors.

Sodium arsenite induces ROS generation, DNA oxidative damage, HO-1 and c-Myc proteins, NF-kappaB activation and cell proliferation in human breast cancer MCF-7 cells.

Epidemiological evidence has associated exposure to arsenic (As) in drinking water with an increased incidence of human cancers in the skin, bladder, liver, kidney and lung. Sodium arsenite mimics the effects of estradiol and induces cell proliferation in the estrogen responsive breast cancer cell line MCF-7. Therefore, our aim was to further explore the ability of sodium arsenite to induce MCF-7 epithelial breast cell proliferation and some of its underlying mechanisms by studying ROS production, c-Myc and HO-1 protein levels, 8-OHdG formation and NF-kappaB activation. Low arsenite concentrations (0.5-5 microM) induced ROS production and ROS-related depolarization of the mitochondrial membrane suggesting that mitochondria played an important role in the oxidative effects of As. ROS-mediated DNA damage as measured by the presence of 8-OHdG DNA-adducts in their nuclei, IkappaB phosphorylation, NF-kappaB activation and increases in c-Myc and HO-1 protein levels were also observed, suggesting that these factors play a relevant role in the arsenite induced MCF-7 cell recruitment into the S-phase of the cell cycle and cell proliferation observed. In conclusion, arsenite activates several pathways involved in MCF-7 cell proliferation suggesting that arsenite exposure may pose a risk for breast cancer in human exposed populations notwithstanding that most studies to date have not yet implicated this metalloid as a cofactor in the etiology of this disease.

Assessing phytochemical intake in a group of Mexican women.

OBJECTIVE: Identify the content of selected phytochemicals (PHYs) in Mexican foods and evaluate the reliability of a food frequency questionnaire (FFQ) in assessing PHYs intake among Mexican women. MATERIAL AND METHODS: Values for PHYs content were obtained from four different data sets. PHYs intake was assessed in 50 women of reproductive age enrolled in a longitudinal cohort study. Values were obtained from a FFQ administered twice, one year apart in order to evaluate its reliability. Selected PHYs included flavonol (FOL), flavones (FES), flavanol (FAL), secoisolariciresinol (SE), matairesinol (MA), lariciresinol (LA), pinoresinol (PI), cynamic acid (CA) and coumestrol (CU). RESULTS: Daily PHYs intake ranged from 1.3 microg +/- 0.9 for MA to 116.3 +/- 43.8 mg for CA. The adjusted correlation coefficients ranged from 0.17 for FAL to 0.47 for LA. Pinto beans, oranges, hot sauce, broccoli, apples and onions were the main sources of the selected PHYs daily intake. DISCUSSION: The results of this study contribute to our understanding of the consumption of PHYs in the Mexican diet, and would help evaluate their potential health impact.

Assessing phytochemical intake in a group of Mexican women

OBJECTIVE: Identify the content of selected phytochemicals (PHYs) in Mexican foods and evaluate the reliability of a food frequency questionnaire (FFQ) in assessing PHYs intake among Mexican women. MATERIAL AND METHODS: Values for PHYs content were obtained from four different data sets. PHYs intake was assessed in 50 women of reproductive age enrolled in a longitudinal cohort study. Values were obtained from a FFQ administered twice, one year apart in order to evaluate its reliability. Selected PHYs included flavonol (FOL), flavones (FES), flavanol (FAL), secoisolariciresinol (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 MA to 116.3 ± 43.8 mg for CA. The adjusted correlation coefficients ranged from 0.17 for FAL to 0.47 for LA. Pinto beans, oranges, hot sauce, broccoli, apples and onions were the main sources of the selected PHYs daily intake. DISCUSSION: The results of this study contribute to our understanding of the consumption of PHYs in the Mexican diet, and would help evaluate their potential health impact.

OBJETIVO: Crear una base de datos con el contenido de nueve fitoestrógenos (FIT) presentes en alimentos mexicanos y calcular su ingestión y reproducibilidad en 50 mujeres participantes en un estudio de cohorte en México. MATERIAL Y MÉTODOS: Los FIT seleccionados incluyeron flavonol (FOL), flavones (FES), flavanol (FAL), secoisolariciresinol (SE), matairesinol (MA), lariciresinol (LA), pinoresinol (PI), ácido cinámico (CA) y coumestrol (CU). El contenido de estos compuestos se obtuvo de cuatro diferentes fuentes de datos. La ingestión diaria se estimó a través de un cuestionario de frecuencia de consumo de alimentos, aplicado en dos oportunidades con una diferencia de un año a cada participante. La reproducibilidad en el reporte de cada FIT se estimó mediante coeficientes de correlación intraclase ajustados por residuales de energía. RESULTADOS: La media de consumo de los FIT seleccionados varió de 1.3 ± 0.8 µg/d de MA hasta 116.3 ± 43.8 mg/d de CA. La reproducibilidad varió desde 0.17 para FAL hasta 0.47 para LA. Las principales fuentes de FIT fueron frijoles, naranja, salsa picante, brócoli, manzana y cebolla. DISCUSION: Este es el primer estudio que calcula la ingestión de FIT en México y podría constituir una herramienta útil para la futura evaluación de su efecto en la salud.

Socioeconomic factors and the risk of anencephaly in a Mexican population: a case-control study.

OBJECTIVE: The study was designed to evaluate the association between socioeconomic level (as measured by maternal education, maternal occupation, and monthly family income) and anencephaly. METHODS: The authors conducted a case-control study using data from the Epidemiological Surveillance System Register for Neural Tube Defects for three states of the Mexican Republic: Puebla, Guerrero and the State of Mexico. Mothers of 151 cases of infants born with anencephaly and mothers of 151 control infants born during the period March 2000 to February 2001 were interviewed about their socioeconomic characteristics and other factors including reproductive history, use of prenatal care, use of tobacco and alcohol, fever during pregnancy, and folic acid supplementation. RESULTS: After adjustment for potential confounders, a risk gradient was seen with decreasing maternal education. Women with less than a primary school education (adjusted odds ratio [OR]=3.0; 95% confidence interval [CI] 1.2, 7.6) and women who had completed primary school but had not completed junior high school (adjusted OR=2.2; 95% CI 0.9, 5.7) had higher risks of giving birth to an infant with anencephaly, compared to women with a higher educational level. A monthly income < or = 1,000 pesos (approximately dollars 100 U.S.) was also associated with a higher risk of anencephaly (OR=2.5; 95% CI 1.2, 5.1). Women employed in industry or agriculture during the acute risk period (three months prior to conception to one month after conception) had a risk 6.5 times (95% CI 1.4, 29.6) that of professional and business women. CONCLUSIONS: This study helps to identify groups that may be especially vulnerable to this type of congenital malformation so that primary and secondary preventive strategies can be targeted to these groups.