RESUMEN
The sedimentary environment is a repository and carrier for a variety of pollutants, and sediment transport from land to coastal areas is an important environmental process. In the present study, we use 210Pb/226Ra and 137Cs in sediment cores to assess sediment supply rates at four sites within the Vefsnfjord in Nordland county, Norway. This area was highly affected by fallout from the Chernobyl accident in 1986 and inventories of 137Cs in the fjord are much higher than in many other Norwegian fjords. Sedimentation rates between 0.042 and 0.25 g cm-2 y-1 (0.060 and 0.38 cm y-1) were determined using a combination of the Constant Rate of Supply (CRS) and Constant Flux:Constant Sedimentation rate (CF:CS) models. Well-defined 137Cs concentration peaks were used as a supplementary tool to the 210Pb dating methods.
Asunto(s)
Contaminantes Radiactivos del Agua , Radioisótopos de Cesio/análisis , Estuarios , Sedimentos Geológicos , Noruega , Contaminantes Radiactivos del Agua/análisisRESUMEN
Frequent and persistent heavy metal pollution has profound effects on the composition and activity of microbial communities. Heavy metals select for metal resistance but can also co-select for resistance to antibiotics, which is a global health concern. We here document metal concentration, metal resistance and antibiotic resistance along a sediment archive from a pond in the North West of the United Kingdom covering over a century of anthropogenic pollution. We specifically focus on zinc, as it is a ubiquitous and toxic metal contaminant known to co-select for antibiotic resistance, to assess the impact of temporal variation in heavy metal pollution on microbial community diversity and to quantify the selection effects of differential heavy metal exposure on antibiotic resistance. Zinc concentration and bioavailability was found to vary over the core, likely reflecting increased industrialisation around the middle of the 20th century. Zinc concentration had a significant effect on bacterial community composition, as revealed by a positive correlation between the level of zinc tolerance in culturable bacteria and zinc concentration. The proportion of zinc resistant isolates was also positively correlated with resistance to three clinically relevant antibiotics (oxacillin, cefotaxime and trimethoprim). The abundance of the class 1 integron-integrase gene, intI1, marker for anthropogenic pollutants correlated with the prevalence of zinc- and cefotaxime resistance but not with oxacillin and trimethoprim resistance. Our microbial palaeontology approach reveals that metal-contaminated sediments from depths that pre-date the use of antibiotics were enriched in antibiotic resistant bacteria, demonstrating the pervasive effects of metal-antibiotic co-selection in the environment.
Asunto(s)
Farmacorresistencia Microbiana , Contaminantes Ambientales/análisis , Metales Pesados/análisis , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/aislamiento & purificación , Farmacorresistencia Microbiana/genética , Monitoreo del Ambiente , Contaminantes Ambientales/historia , Genes Bacterianos , Sedimentos Geológicos/análisis , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Metales Pesados/historia , Microbiota , Paleontología/métodos , Estanques/microbiología , Reino Unido , Microbiología del Agua , Contaminación del Agua/análisis , Contaminación del Agua/historiaRESUMEN
BACKGROUND: Microseminoprotein-beta (MSP), a protein secreted by the prostate epithelium, may have a protective role in the development of prostate cancer. The only previous prospective study found a 2% reduced prostate cancer risk per unit increase in MSP. This work investigates the association of MSP with prostate cancer risk using observational and Mendelian randomization (MR) methods. PATIENTS AND METHODS: A nested case-control study was conducted with the European Prospective Investigation into Cancer and Nutrition (EPIC) with 1871 cases and 1871 matched controls. Conditional logistic regression analysis was used to investigate the association of pre-diagnostic circulating MSP with risk of incident prostate cancer overall and by tumour subtype. EPIC-derived estimates were combined with published data to calculate an MR estimate using two-sample inverse-variance method. RESULTS: Plasma MSP concentrations were inversely associated with prostate cancer risk after adjusting for total prostate-specific antigen concentration [odds ratio (OR) highest versus lowest fourth of MSP = 0.65, 95% confidence interval (CI) 0.51-0.84, Ptrend = 0.001]. No heterogeneity in this association was observed by tumour stage or histological grade. Plasma MSP concentrations were 66% lower in rs10993994 TT compared with CC homozygotes (per allele difference in MSP: 6.09 ng/ml, 95% CI 5.56-6.61, r2=0.42). MR analyses supported a potentially causal protective association of MSP with prostate cancer risk (OR per 1 ng/ml increase in MSP for MR: 0.96, 95% CI 0.95-0.97 versus EPIC observational: 0.98, 95% CI 0.97-0.99). Limitations include lack of complete tumour subtype information and more complete information on the biological function of MSP. CONCLUSIONS: In this large prospective European study and using MR analyses, men with high circulating MSP concentration have a lower risk of prostate cancer. MSP may play a causally protective role in prostate cancer.
Asunto(s)
Neoplasias de la Próstata/sangre , Proteínas de Secreción Prostática/sangre , Biomarcadores de Tumor/sangre , Estudios de Casos y Controles , Estudios de Seguimiento , Humanos , Masculino , Análisis de la Aleatorización Mendeliana/métodos , Persona de Mediana Edad , Estado Nutricional , Pronóstico , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND/OBJECTIVES: Previous small studies have shown either no difference or a lower risk of symptomatic gallstone disease in vegetarians than in non-vegetarians. This study examined the incidence of symptomatic gallstone disease in a cohort of British vegetarians and non-vegetarians, and investigated the associations between nutrient intake and risk of symptomatic gallstone disease. SUBJECTS/METHODS: The data were analysed from 49 652 adults enroled in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study, one-third of whom were vegetarian. The linked databases of hospital records were used to identify incident cases. Risk by diet group was estimated using Cox proportional hazards models. Further analysis quantified risk by intakes of selected macronutrients. RESULTS: There were 1182 cases of symptomatic gallstone disease during 687 822 person-years of follow-up (mean=13.85 years). There was a large significant association between increasing body mass index (BMI) and risk of developing symptomatic gallstone disease (overall trend P<0.001). After adjustment for BMI and other risk factors, vegetarians had a moderately increased risk compared with non-vegetarians (HR: 1.22; 95% CI: 1.06-1.41; P=0.006). Although starch consumption was positively associated with gallstones risk (P=0.002 for trend), it did not explain the increased risk in vegetarians. CONCLUSIONS: There is a highly significant association of increased BMI with risk of symptomatic gallstone disease. After adjusting for BMI, there is a small but statistically significant positive association between vegetarian diet and symptomatic gallstone disease.
Asunto(s)
Dieta Vegetariana/efectos adversos , Cálculos Biliares/epidemiología , Adulto , Índice de Masa Corporal , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Fibras de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Femenino , Estudios de Seguimiento , Cálculos Biliares/etiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Evaluación Nutricional , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND/OBJECTIVES: The influence of dietary factors remains controversial for screen-detected prostate cancer and inconclusive for clinically detected disease. We aimed to examine these associations using prospectively collected food diaries. SUBJECTS/METHODS: A total of 1,717 prostate cancer cases in middle-aged and older UK men were pooled from four prospective cohorts with clinically detected disease (n=663), with routine data follow-up (means 6.6-13.3 years) and a case-control study with screen-detected disease (n=1054), nested in a randomised trial of prostate cancer treatments (ISCTRN 20141297). Multiple-day food diaries (records) completed by men prior to diagnosis were used to estimate intakes of 37 selected nutrients, food groups and items, including carbohydrate, fat, protein, dairy products, fish, meat, fruit and vegetables, energy, fibre, alcohol, lycopene and selenium. Cases were matched on age and diary date to at least one control within study (n=3528). Prostate cancer risk was calculated, using conditional logistic regression (adjusted for baseline covariates) and expressed as odds ratios in each quintile of intake (±95% confidence intervals). Prostate cancer risk was also investigated by localised or advanced stage and by cancer detection method. RESULTS: There were no strong associations between prostate cancer risk and 37 dietary factors. CONCLUSIONS: Prostate cancer risk, including by disease stage, was not strongly associated with dietary factors measured by food diaries in middle-aged and older UK men.
Asunto(s)
Registros de Dieta , Alimentos/efectos adversos , Micronutrientes/análisis , Neoplasias de la Próstata/etiología , Adulto , Anciano , Estudios de Casos y Controles , Dieta/efectos adversos , Dieta/estadística & datos numéricos , Estudios de Seguimiento , Alimentos/estadística & datos numéricos , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Estudios Prospectivos , Factores de Riesgo , Reino UnidoRESUMEN
The residence time of (210)Pb created in the atmosphere by the decay of gaseous (222)Rn is a key parameter controlling its distribution and fallout onto the landscape. These in turn are key parameters governing the use of this natural radionuclide for dating and interpreting environmental records stored in natural archives such as lake sediments. One of the principal methods for estimating the atmospheric residence time is through measurements of the activities of the daughter radionuclides (210)Bi and (210)Po, and in particular the (210)Bi/(210)Pb and (210)Po/(210)Pb activity ratios. Calculations used in early empirical studies assumed that these were governed by a simple series of equilibrium equations. This approach does however have two failings; it takes no account of the effect of global circulation on spatial variations in the activity ratios, and no allowance is made for the impact of transport processes across the tropopause. This paper presents a simple model for calculating the distributions of (210)Pb, (210)Bi and (210)Po at northern mid-latitudes (30°-65°N), a region containing almost all the available empirical data. By comparing modelled (210)Bi/(210)Pb activity ratios with empirical data a best estimate for the tropospheric residence time of around 10 days is obtained. This is significantly longer than earlier estimates of between 4 and 7 days. The process whereby (210)Pb is transported into the stratosphere when tropospheric concentrations are high and returned from it when they are low, significantly increases the effective residence time in the atmosphere as a whole. The effect of this is to significantly enhance the long range transport of (210)Pb from its source locations. The impact is illustrated by calculations showing the distribution of (210)Pb fallout versus longitude at northern mid-latitudes.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Bismuto/análisis , Plomo/análisis , Polonio/análisis , Radioisótopos/análisis , Atmósfera , Modelos Teóricos , Monitoreo de RadiaciónRESUMEN
BACKGROUND/OBJECTIVES: We aimed to investigate the differences in plasma concentrations and in intakes of amino acids between male meat-eaters, fish-eaters, vegetarians and vegans in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. SUBJECTS/METHODS: This cross-sectional analysis included 392 men, aged 30-49 years. Plasma amino acid concentrations were measured with a targeted metabolomic approach using mass spectrometry, and dietary intake was assessed using a food frequency questionnaire. Differences between diet groups in mean plasma concentrations and intakes of amino acids were examined using analysis of variance, controlling for potential confounding factors and multiple testing. RESULTS: In plasma, concentrations of 6 out of 21 amino acids varied significantly by diet group, with differences of -13% to +16% between meat-eaters and vegans. Concentrations of methionine, tryptophan and tyrosine were highest in fish-eaters and vegetarians, followed by meat-eaters, and lowest in vegans. A broadly similar pattern was seen for lysine, whereas alanine concentration was highest in fish-eaters and lowest in meat-eaters. For glycine, vegans had the highest concentration and meat-eaters the lowest. Intakes of all 18 dietary amino acids differed by diet group; for the majority of these, intake was highest in meat-eaters followed by fish-eaters, then vegetarians and lowest in vegans (up to 47% lower than in meat-eaters). CONCLUSIONS: Men belonging to different habitual diet groups have significantly different plasma concentrations of lysine, methionine, tryptophan, alanine, glycine and tyrosine. However, the differences in plasma concentrations were less marked than and did not necessarily mirror those seen for amino acid intakes.
Asunto(s)
Aminoácidos/sangre , Dieta Vegana , Dieta Vegetariana , Carne , Alimentos Marinos , Adulto , Alanina/sangre , Animales , Estudios Transversales , Ingestión de Energía , Peces , Glicina/sangre , Humanos , Lisina/sangre , Masculino , Metionina/sangre , Persona de Mediana Edad , Encuestas y Cuestionarios , Triptófano/sangre , Tirosina/sangreRESUMEN
Epidemiological studies have examined breast cancer risk in relation to sex hormone concentrations measured by different methods: "extraction" immunoassays (with prior purification by organic solvent extraction, with or without column chromatography), "direct" immunoassays (no prior extraction or column chromatography), and more recently with mass spectrometry-based assays. We describe the associations of estradiol, estrone and testosterone with both body mass index and breast cancer risk in postmenopausal women according to assay method, using data from a collaborative pooled analysis of 18 prospective studies. In general, hormone concentrations were highest in studies that used direct assays and lowest in studies that used mass spectrometry-based assays. Estradiol and estrone were strongly positively associated with body mass index, regardless of the assay method; testosterone was positively associated with body mass index for direct assays, but less clearly for extraction assays, and there were few data for mass spectrometry assays. The correlations of estradiol with body mass index, estrone and testosterone were lower for direct assays than for extraction and mass spectrometry assays, suggesting that the estimates from the direct assays were less precise. For breast cancer risk, all three hormones were strongly positively associated with risk regardless of assay method (except for testosterone by mass spectrometry where there were few data), with no statistically significant differences in the trends, but differences may emerge as new data accumulate. Future epidemiological and clinical research studies should continue to use the most accurate assays that are feasible within the design characteristics of each study.
Asunto(s)
Índice de Masa Corporal , Neoplasias de la Mama/etiología , Estradiol/sangre , Estrona/sangre , Posmenopausia/sangre , Testosterona/sangre , Femenino , Humanos , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND/OBJECTIVES: The objective of this study was to describe serum lipid concentrations, including apolipoproteins A-I and B, in different diet groups. SUBJECTS/METHODS: A cross-sectional analysis of a sample of 424 meat-eaters, 425 fish-eaters, 423 vegetarians and 422 vegans, matched on sex and age, from the European Prospective Investigation into Cancer and Nutrition-Oxford cohort. Serum concentrations of total, and high-density lipoprotein (HDL) cholesterol, as well as apolipoproteins A-I and B were measured, and serum non-HDL cholesterol was calculated. RESULTS: Vegans had the lowest body mass index (BMI) and the highest and lowest intakes of polyunsaturated and saturated fat, respectively. After adjustment for age, alcohol and physical activity, compared with meat-eaters, fish-eaters and vegetarians, serum concentrations of total and non-HDL cholesterol and apolipoprotein B were significantly lower in vegans. Serum apolipoprotein A-I concentrations did not differ between the diet groups. In males, the mean serum total cholesterol concentration was 0.87 mmol/l lower in vegans than in meat-eaters; after further adjustment for BMI this difference was 0.76 mmol/l. In females, the difference in total cholesterol between these two groups was 0.6 mmol/l, and after further adjustment for BMI was 0.55 mmol/l. [corrected]. CONCLUSIONS: In this study, which included a large number of vegans, serum total cholesterol and apolipoprotein B concentrations were lower in vegans compared with meat-eaters, fish-eaters and vegetarians. A small proportion of the observed differences in serum lipid concentrations was explained by differences in BMI, but a large proportion is most likely due to diet.
Asunto(s)
Apolipoproteína A-I/sangre , Apolipoproteínas B/sangre , Colesterol/sangre , Dieta , Peces , Carne , Adulto , Consumo de Bebidas Alcohólicas , Animales , Índice de Masa Corporal , HDL-Colesterol/sangre , Estudios Transversales , Dieta Vegetariana , Fibras de la Dieta/administración & dosificación , Ingestión de Energía , Ejercicio Físico , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Associations between circulating concentrations of oestrogens, progesterone, and androgens with breast cancer and related risk factors in premenopausal women are not well understood. We aimed to characterise these associations with a pooled analysis of data from seven studies. METHODS: Individual participant data for prediagnostic sex hormone and sex hormone-binding globulin (SHBG) concentrations were contributed from seven prospective studies. We restricted analyses to women who were premenopausal and younger than 50 years at blood collection, and to women with breast cancer diagnosed before age 50 years. We estimated odds ratios (ORs) with 95% CIs for breast cancer associated with hormone concentrations by conditional logistic regression in cases and controls matched for age, date of blood collection, and day of cycle, with stratification by study and further adjustment for cycle phase. We examined associations of hormones with risk factors for breast cancer in control women by comparing geometric mean hormone concentrations in categories of these risk factors, adjusted for study, age, phase of menstrual cycle, and body-mass index (BMI). All statistical tests were two-sided. FINDINGS: We included data for up to 767 women with breast cancer and 1699 controls in the risk analyses. Breast cancer risk was associated with a doubling in concentrations of oestradiol (OR 1·19, 95% CI 1·06-1·35), calculated free oestradiol (1·17, 1·03-1·33), oestrone (1·27, 1·05-1·54), androstenedione (1·30, 1·10-1·55), dehydroepiandrosterone sulphate (1·17, 1·04-1·32), testosterone (1·18, 1·03-1·35), and calculated free testosterone (1·08, 0·97-1·21). Breast cancer risk was not associated with luteal phase progesterone (doubling in concentration OR 1·00, 95% CI 0·92-1·09), and adjustment for other factors had little effect on any of these ORs. Cross-sectional analyses in control women showed several associations of sex hormones with breast cancer risk factors. INTERPRETATION: Circulating oestrogens and androgens are positively associated with the risk for breast cancer in premenopausal women.
Asunto(s)
Neoplasias de la Mama/etiología , Hormonas Esteroides Gonadales/sangre , Premenopausia , Adulto , Índice de Masa Corporal , Neoplasias de la Mama/sangre , Conducta Cooperativa , Sulfato de Deshidroepiandrosterona/sangre , Femenino , Humanos , Estudios Prospectivos , Globulina de Unión a Hormona Sexual/análisisRESUMEN
The present study focuses on the detection of Sellafield-derived (137)Cs and (241)Am in contaminated saltmarshes from North-West England, UK, with a view to assessing the radiological impacts from radioactivity stored within the sediment record. The surface activities from these radionuclides were found in the range between 73 and 851 Bq kg(-1) whereas peak activities ranging from 383 to 12690 Bq kg(-1) were found below the surface of the upper marsh at a depth of approximately 5-20 cm. Potential radioactive exposure to humans from these highly active radionuclides comes mainly from direct exposure and resuspended dust inhalation for different saltmarsh users, which may be exacerbated by the remobilisation of radionuclides resulting from saltmarsh erosion. The total annual minimum, maximum and 'best estimate' doses ranging from 11 to 972 µSv y(-1), fall below the ICRP-recommended annual dose limit, but the highest estimated total effective dose (972 µSv y(-1)) for a marsh user falls within 97% of the recommended dose limit and the highest 'best estimate' total annual doses of 110 and 307 µSv y(-1) for Dee estuary and Biggar marshes, respectively, are almost 3 and 4 times higher than the estimated doses that are based on existing surface activities.
Asunto(s)
Americio/análisis , Radioisótopos de Cesio/análisis , Contaminantes Radiactivos del Agua/análisis , Humedales , Americio/química , Radioisótopos de Cesio/química , Inglaterra , Monitoreo de Radiación , Medición de Riesgo , Contaminantes Radiactivos del Agua/químicaRESUMEN
Cadmium zinc telluride (CdZnTe or CZT) is the leading semiconductor detector for gamma spectroscopy at room temperature. In the present study, a coplanar-grid CZT detector was used for gamma-ray measurements of environmental radioactivity on a contaminated saltmarsh sediment core in comparison with results from a coaxial high-purity germanium detector to assess their comparative performance. The findings reveal that the CZT performs well for both (241)Am and (137)Cs measurements over a broad range of activities, despite limited detector efficiency, and can be used to good effect in the study of environmental radioactivity in contaminated estuarine settings.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Cadmio/química , Monitoreo del Ambiente , Rayos gamma , Semiconductores , Contaminantes Radiactivos del Suelo/análisis , Telurio/química , Zinc/química , Americio/análisis , Radioisótopos de Cesio/análisis , Diseño de Equipo , Sedimentos Geológicos/química , Germanio/análisis , Fantasmas de ImagenRESUMEN
BACKGROUND/OBJECTIVES: Evidence from prospective studies is consistent in showing an inverse association between dietary fibre intake and risk of ischaemic heart disease (IHD), but whether dietary fibre from various food sources differ in their effect on IHD risk is less clear. The objective of this study was to assess the associations of total and food sources of dietary fibre with IHD mortality in the European Prospective Investigation into Cancer and Nutrition-Heart study. SUBJECTS/METHODS: Participants were 306,331 men and women from eight European countries. Dietary fibre intake was assessed using centre or country-specific diet questionnaires and calibrated using a 24-h diet recall. RESULTS: After an average follow-up of 11.5 years, there were 2381 IHD deaths among participants without cardiovascular disease at baseline. The calibrated intake of dietary fibre was inversely related with IHD mortality; each 10 g/day was associated with a 15% lower risk (relative risk (RR) 0.85; 95% confidence interval (CI): 0.73-0.99, P=0.031). There was no difference in the associations of the individual food sources of dietary fibre with the risk of IHD mortality; RR for each 5 g/day higher cereal fibre intake was 0.91 (CI: 0.82-1.01), RR for each 2.5 g/day fruit fibre intake was 0.94 (CI: 0.88-1.01) and RR for each 2.5 g/day vegetable fibre intake was 0.90 (95% CI: 0.76-1.07). CONCLUSION: A higher consumption of dietary fibre is associated with a lower risk of fatal IHD with no clear difference in the association with IHD for fibre from cereals, fruits or vegetables.
Asunto(s)
Fibras de la Dieta/administración & dosificación , Isquemia Miocárdica/epidemiología , Neoplasias/epidemiología , Índice de Masa Corporal , Dieta , Grano Comestible , Europa (Continente)/epidemiología , Femenino , Estudios de Seguimiento , Frutas , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Estado Nutricional , Estudios Prospectivos , Análisis de Regresión , Factores de Riesgo , Encuestas y Cuestionarios , VerdurasRESUMEN
BACKGROUND: Breast cancer risk for postmenopausal women is positively associated with circulating concentrations of oestrogens and androgens, but the determinants of these hormones are not well understood. METHODS: Cross-sectional analyses of breast cancer risk factors and circulating hormone concentrations in more than 6000 postmenopausal women controls in 13 prospective studies. RESULTS: Concentrations of all hormones were lower in older than younger women, with the largest difference for dehydroepiandrosterone sulphate (DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the older women. Androgens were lower in women with bilateral ovariectomy than in naturally postmenopausal women, with the largest difference for free testosterone. All hormones were higher in obese than lean women, with the largest difference for free oestradiol, whereas SHBG was lower in obese women. Smokers of 15+ cigarettes per day had higher levels of all hormones than non-smokers, with the largest difference for testosterone. Drinkers of 20+ g alcohol per day had higher levels of all hormones, but lower SHBG, than non-drinkers, with the largest difference for DHEAS. Hormone concentrations were not strongly related to age at menarche, parity, age at first full-term pregnancy or family history of breast cancer. CONCLUSION: Sex hormone concentrations were strongly associated with several established or suspected risk factors for breast cancer, and may mediate the effects of these factors on breast cancer risk.
Asunto(s)
Neoplasias de la Mama/etiología , Carcinoma/etiología , Hormonas Esteroides Gonadales/sangre , Posmenopausia/sangre , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/sangre , Carcinoma/sangre , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Embarazo , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND/OBJECTIVES: Vegans, and to a lesser extent vegetarians, have low average circulating concentrations of vitamin B12; however, the relation between factors such as age or time on these diets and vitamin B12 concentrations is not clear. The objectives of this study were to investigate differences in serum vitamin B12 and folate concentrations between omnivores, vegetarians and vegans and to ascertain whether vitamin B12 concentrations differed by age and time on the diet. SUBJECTS/METHODS: A cross-sectional analysis involving 689 men (226 omnivores, 231 vegetarians and 232 vegans) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort. RESULTS: Mean serum vitamin B12 was highest among omnivores (281, 95% CI: 270-292 pmol/l), intermediate among vegetarians (182, 95% CI: 175-189 pmol/l) and lowest among vegans (122, 95% CI: 117-127 pmol/l). In all, 52% of vegans, 7% of vegetarians and one omnivore were classified as vitamin B12 deficient (defined as serum vitamin B12 <118 pmol/l). There was no significant association between age or duration of adherence to a vegetarian or a vegan diet and serum vitamin B12. In contrast, folate concentrations were highest among vegans, intermediate among vegetarians and lowest among omnivores, but only two men (both omnivores) were categorized as folate deficient (defined as serum folate <6.3 nmol/l). CONCLUSION: Vegans have lower vitamin B12 concentrations, but higher folate concentrations, than vegetarians and omnivores. Half of the vegans were categorized as vitamin B12 deficient and would be expected to have a higher risk of developing clinical symptoms related to vitamin B12 deficiency.
Asunto(s)
Dieta Vegetariana , Dieta , Deficiencia de Ácido Fólico/epidemiología , Ácido Fólico/sangre , Deficiencia de Vitamina B 12/epidemiología , Vitamina B 12/sangre , Adulto , Factores de Edad , Anciano , Estudios de Cohortes , Estudios Transversales , Ácido Fólico/administración & dosificación , Deficiencia de Ácido Fólico/sangre , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Necesidades Nutricionales , Estado Nutricional , Estudios Prospectivos , Factores de Tiempo , Reino Unido/epidemiología , Vitamina B 12/administración & dosificación , Deficiencia de Vitamina B 12/sangre , Complejo Vitamínico B/sangre , Adulto JovenRESUMEN
BACKGROUND: Few prospective studies have examined cancer incidence among vegetarians. METHODS: We studied 61,566 British men and women, comprising 32,403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20,601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use. RESULTS: There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07-1.20) in fish eaters and 0.36 (0.16-0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18-0.77) in fish eaters and 0.69 (0.45-1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36-1.81) in fish eaters and 0.47 (0.25-0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56-1.29) in fish eaters and 0.55 (0.39-0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73-0.93) in fish eaters and 0.88 (0.81-0.96) in vegetarians (P for heterogeneity=0.001). CONCLUSION: The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters.
Asunto(s)
Dieta Vegetariana , Neoplasias/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Femenino , Peces , Humanos , Incidencia , Masculino , Carne , Persona de Mediana Edad , Reino Unido , Adulto JovenRESUMEN
We examined plasma concentrations of phyto-oestrogens in relation to risk for subsequent prostate cancer in a case-control study nested in the European Prospective Investigation into Cancer and Nutrition. Concentrations of isoflavones genistein, daidzein and equol, and that of lignans enterolactone and enterodiol, were measured in plasma samples for 950 prostate cancer cases and 1042 matched control participants. Relative risks (RRs) for prostate cancer in relation to plasma concentrations of these phyto-oestrogens were estimated by conditional logistic regression. Higher plasma concentrations of genistein were associated with lower risk of prostate cancer: RR among men in the highest vs the lowest fifth, 0.71 (95% confidence interval (CI) 0.53-0.96, P trend=0.03). After adjustment for potential confounders this RR was 0.74 (95% CI 0.54-1.00, P trend=0.05). No statistically significant associations were observed for circulating concentrations of daidzein, equol, enterolactone or enterodiol in relation to overall risk for prostate cancer. There was no evidence of heterogeneity in these results by age at blood collection or country of recruitment, nor by cancer stage or grade. These results suggest that higher concentrations of circulating genistein may reduce the risk of prostate cancer but do not support an association with plasma lignans.
Asunto(s)
Dieta , Fitoestrógenos/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/epidemiología , Estudios de Casos y Controles , Europa (Continente) , Genisteína/sangre , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
We examined consumption of animal foods, protein and calcium in relation to risk of prostate cancer among 142 251 men in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by recruitment centre and adjusted for height, weight, education, marital status and energy intake. After an average of 8.7 years of follow-up, there were 2727 incident cases of prostate cancer, of which 1131 were known to be localised and 541 advanced-stage disease. A high intake of dairy protein was associated with an increased risk, with a hazard ratio for the top versus the bottom fifth of intake of 1.22 (95% confidence interval (CI): 1.07-1.41, P(trend)=0.02). After calibration to allow for measurement error, we estimated that a 35-g day(-1) increase in consumption of dairy protein was associated with an increase in the risk of prostate cancer of 32% (95% CI: 1-72%, P(trend)=0.04). Calcium from dairy products was also positively associated with risk, but not calcium from other foods. The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer.