BackgroundPhthalates, 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.ObjectivesIn this study, we examined the association between urinary concentrations of nine phthalate metabolites and breast cancer (BC) in Mexican women.MethodsWe 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.ResultsPhthalate 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.ConclusionsWe 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 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. ' UICCKey words: nitrate; nitrite; diet; polyphenols; gastric cancer In Mexico, gastric cancer (GC) rates show an increasing trend with time, 1 in contrast to other countries, and remains the 2nd leading cause of cancer mortality. 2 Nitrate and nitrite are precursors for the endogenous formation of N-nitroso compounds (NOC), which are carcinogenic in animals and, potentially, in humans. 3 Ingested nitrate is absorbed in the small intestine and 25% is excreted in the mouth, where oral bacteria reduce about 20% to nitrite (about 5% of ingested nitrate).In the acidic stomach, nitrite forms nitrous acid, which decomposes into various reactive nitrogen species (RNS). Nitrite and RNS react with nitrosatable compounds, mainly amines and amides, to form NOC. 4 The formation of NOC is inhibited by some antioxidants, such as polyphenols 5,6 and vitamins C and E. 4,7 For this reason, a low consumption of these inhibitors of NOC formation, (INC) together with a high consumption of nitrate and/or nitrite, results in an increase in the endogenous formation of NOC. 3 Contrasting with consistent results showing an increase in the risk of GC because of nitrite consumption, 8 the association with nitrate intake is less certain. Some investigators observed no association with nitrate consumption 9-16 ; whereas, others have observed a decrease in GC risk with increasing nitrate consumption. 17,18 These apparent contradictory results reflect the...

BackgroundCivilization 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.MethodsOf 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.ResultsObese 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 < 0.04) and refined carbohydrates with added fat (p Trend = 0.002) were associated with an increased risk of obesity. Children who were more physically active at school had an OR of 0.37 (CI 0.16; 0.89), those who had 3–4 televisions at home had an OR of 2.13 (CI 1.20; 3.78), and the risk of developing obesity was independent of caloric intake.ConclusionsPoorer eating habits as well as less physical activity were associated with the risk of obesity. An obesogenic environment could change if teachers and parents worked together to form healthy food intake and physical activity habits.

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.

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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.

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.

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.