Work Productivity Among Younger Breast Cancer Survivors: The Impact of Behavioral Interventions for Depression.

OBJECTIVES: The Pathways to Wellness randomized controlled trial found that 2 behavioral interventions, mindfulness awareness practices and survivorship education, reduced depressive symptoms in younger breast cancer survivors (BCSs) compared with wait-list control. This secondary analysis examines whether the interventions led to reduced loss of work productivity among younger BCSs and whether such reductions were mediated by reductions in depressive symptoms. METHODS: The Work Productivity and Activity Impairment scale was used to measure work productivity loss at 4 assessment time points. Correlates of productivity loss at enrollment were examined using multivariable linear regression. Differences in change over time in productivity loss between each intervention group and control were assessed using linear mixed models. Reduced depressive symptoms were tested as a mediator of reduced productivity loss. RESULTS: Of 247 trial participants, 199 were employed and included in the analyses. At enrollment, higher productivity loss was associated with chemotherapy receipt (P = .003), younger age (P = .021), more severe cognitive problems (P = .002), higher musculoskeletal pain severity (P = .002), more depressive symptoms (P = .016), and higher fatigue severity (P = .033). The mindfulness intervention led to significantly less productivity loss compared with control at all 3 postintervention assessment points (all P < .05), with about 54% of the effect mediated by reduction in depressive symptoms. Survivorship education was not associated with reduced loss of productivity. CONCLUSIONS: These findings suggest that addressing depressive symptoms through behavioral interventions, such as mindfulness, may mitigate impacts on work productivity in younger BCSs.

Targeting Depressive Symptoms in Younger Breast Cancer Survivors: The Pathways to Wellness Randomized Controlled Trial of Mindfulness Meditation and Survivorship Education.

PURPOSE: Younger women are at risk for depression and related symptoms following breast cancer. The Pathways to Wellness study, a randomized, multi-institution, three-arm trial, tested the efficacy of two behavioral interventions for younger breast cancer survivors with elevated depressive symptoms: mindful awareness practices (MAPs) and survivorship education (SE) (Clincaltrials.gov identifier: NCT03025139). METHODS: Women diagnosed with breast cancer at or before 50 years of age who had completed treatment and had elevated depressive symptoms were randomly assigned to 6 weeks of MAPs, SE, or wait-list control (WLC). Assessments were conducted preintervention and postintervention and at 3-month and 6-month postintervention follow-ups. Analyses compared each intervention to WLC using linear mixed models. The primary outcome was change in depressive symptoms from preintervention to postintervention on the Center for Epidemiologic Studies-Depression Scale; secondary outcomes included change in fatigue, insomnia, and vasomotor symptoms. RESULTS: Two hundred forty-seven women (median age = 46 years) were randomly assigned to MAPs (n = 85), SE (n = 81), or WLC (n = 81). MAPs and SE led to significant decreases in depressive symptoms from preintervention to postintervention relative to WLC (mean change relative to WLC [95% CI]: MAPs, -4.7 [-7.5 to -1.9]; SE, -4.0 [-6.9 to -1.1]), which persisted at 6-month follow-up for MAPs (mean change relative to WLC [95% CI]: MAPs, -3.7 [-6.6 to -0.8]; SE, -2.8 [-5.9 to 0.2]). MAPs, but not SE, also had beneficial effects on fatigue, insomnia, and vasomotor symptoms that persisted at 6-month follow-up (P < .05). CONCLUSION: Mindfulness meditation and SE reduced depressive symptoms in younger breast cancer survivors. These interventions can be widely disseminated over virtual platforms and have significant potential benefit for quality of life and overall survivorship in this vulnerable group.

The role of income and neighbourhood poverty in the association between the 2009 Special Supplemental Nutrition Program for Women, Infants and Children (WIC) food package change and child obesity among WIC-participating children in Los Angeles County, 2003-2016.

OBJECTIVE: To determine whether a previously reported association between the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) food package change and reduced child obesity risk among WIC-participating children in Los Angeles County holds across levels of family income and neighbourhood poverty. DESIGN: Analysis of prospectively collected WIC administrative data. The outcome was obesity at age 4 years (BMI-for-age ≥ 95th percentile). Poisson regression was applied to a matched sample (n 79 502) to determine if the association between the WIC food package change and child obesity was modified by family income (<50 % federal poverty level (FPL), 50-100 % FPL, >100 % but <185 % FPL) and neighbourhood poverty. SETTING: Los Angeles County, California. PARTICIPANTS: Children who participated in WIC in Los Angeles County between 2003 and 2016; children were grouped as receiving the old WIC food package (2003-2009) or the new WIC food package (2010-2016). RESULTS: Receiving the new WIC food package (i.e., post-2009) was associated with 7-18 % lower obesity risk across all family income categories. Neither family income nor neighbourhood poverty significantly modified the association between the WIC food package and child obesity. However, certain sub-groups seemed to benefit more from the food package change than others. In particular, boys from families with income above poverty but residing in the poorest neighbourhoods experienced the greatest reductions in obesity risk (relative risk = 0·77; 95 % CI 0·66, 0·88). CONCLUSIONS: The WIC food package revisions were associated with reduced childhood obesity risk among all WIC-participating families in Los Angeles County, across levels of income eligibility and neighbourhood poverty.

Every month matters: longitudinal associations between exclusive breastfeeding duration, child growth and obesity among WIC-participating children.

BACKGROUND: Research has found breastfeeding to be protective of obesity; however, this link remains contentious. We examined longitudinal associations between exclusive breastfeeding duration, growth trajectories and obesity at 4 years among children participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), and whether these associations differed in the context of the 2009 WIC food package change, implemented to improve alignment with dietary guidelines and promote breastfeeding. METHODS: Longitudinal data from 260 935 WIC-participating children in Los Angeles County, California, 2003-2016, were used to assess the relationship between duration of receipt of the fully breastfeeding package (an exclusive breastfeeding proxy) with childhood growth and obesity using mixed effects and Poisson regression models. RESULTS: Children exclusively breastfed for longer duration had healthier growth trajectories and lower obesity risk at age 4. Compared with infants with no fully breastfeeding package receipt, any receipt (a breastfeeding initiation proxy) was associated with reduced obesity risk. Obesity risk was lowest for boys and girls exclusively breastfed for 7 (risk ratio (RR)=0.73, 95% CI=0.64 to 0.82) and 13 months (RR=0.63, 95% CI=0.58 to 0.69), respectively. Exclusive breastfeeding duration increased, but associations between exclusive breastfeeding duration and growth and obesity were not modified, following the 2009 WIC food package change. CONCLUSION: Increased duration of exclusive breastfeeding was associated with reduced obesity risk. The greatest incremental benefit was observed going from none to any exclusive breastfeeding, and the maximum cumulative benefit was among children receiving the fully breastfeeding package for more than 6 months. Breastfeeding promotion in WIC remains important for obesity prevention.

A preventive intervention to modify depression risk targets after breast cancer diagnosis: Design and single-arm pilot study.

OBJECTIVE: Apply the National Institutes of Health (NIH) Stage Model to design and test an intervention to prevent depression in breast cancer patients at risk for depression. METHODS: We identified mindful emotion awareness, along with approach and avoidance strategies for cancer-related coping and emotion regulation, as targets for a preventive intervention adapted from the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders. Patients' preferences for individual, in-person, and time-efficient sessions informed the design. Patients at risk for depression received a 6-week, 5-hour intervention with daily exercises. Intervention targets were assessed at baseline, before each session, and 4-weeks post intervention. Mixed effects analysis of variance (ANOVA) assessed change over the follow-up period, controlling for age, partnered status, and disease stage. RESULTS: Fifty-five percent (40/72) of women screened within 6 months of diagnosis had elevated depression risk. Of these, 24 (60%) signed consent. Sixteen received intervention after five were excluded for current depressive disorder, cognitive impairment, or death. Three dropped out. Ninety-eight percent attendance and 77% practice days indicated feasibility. Effect sizes (Cohen's d) corrected for regression to the mean (RTM) were 0.82 for cancer-related acceptance coping, 0.65 for cancer-related emotional expression, and 0.32 and 0.42 for decreased cancer-related avoidance coping and depressive symptoms, respectively. Effect sizes for variables lacking data to correct for RTM were 1.0, 0.7, and 0.5 for decreased rumination, experiential avoidance, and fear of depression, respectively, and 1.3, 0.6, and 0.4 for increased cognitive flexibility, distress tolerance, and describing/not judging emotions, respectively. CONCLUSIONS: The feasibility of this intervention and malleability of its targets support its further investigation.

Selenium for preventing cancer.

BACKGROUND: This review is the third update of the Cochrane review "Selenium for preventing cancer". Selenium is a naturally occurring element with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancer. OBJECTIVES: To gather and present evidence needed to address two research questions:1. What is the aetiological relationship between selenium exposure and cancer risk in humans?2. Describe the efficacy of selenium supplementation for cancer prevention in humans. SEARCH METHODS: We updated electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE (Ovid, 2013 to January 2017, week 4), and Embase (2013 to 2017, week 6), as well as searches of clinical trial registries. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and longitudinal observational studies that enrolled adult participants. DATA COLLECTION AND ANALYSIS: We performed random-effects (RE) meta-analyses when two or more RCTs were available for a specific outcome. We conducted RE meta-analyses when five or more observational studies were available for a specific outcome. We assessed risk of bias in RCTs and in observational studies using Cochrane's risk assessment tool and the Newcastle-Ottawa Scale, respectively. We considered in the primary analysis data pooled from RCTs with low risk of bias. We assessed the certainty of evidence by using the GRADE approach. MAIN RESULTS: We included 83 studies in this updated review: two additional RCTs (10 in total) and a few additional trial reports for previously included studies. RCTs involved 27,232 participants allocated to either selenium supplements or placebo. For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence). The RR for estimated cancer mortality was 1.02 (95% CI 0.80 to 1.30; 1 study, 17,444 participants). For the most frequently investigated site-specific cancers, investigators provided little evidence of any effect of selenium supplementation. Two RCTs with 19,009 participants indicated that colorectal cancer was unaffected by selenium administration (RR 0.99, 95% CI 0.69 to 1.43), as were non-melanoma skin cancer (RR 1.16, 95% CI 0.30 to 4.42; 2 studies, 2027 participants), lung cancer (RR 1.16, 95% CI 0.89 to 1.50; 2 studies, 19,009 participants), breast cancer (RR 2.04, 95% CI 0.44 to 9.55; 1 study, 802 participants), bladder cancer (RR 1.07, 95% CI 0.76 to 1.52; 2 studies, 19,009 participants), and prostate cancer (RR 1.01, 95% CI 0.90 to 1.14; 4 studies, 18,942 participants). Certainty of the evidence was high for all of these cancer sites, except for breast cancer, which was of moderate certainty owing to imprecision, and non-melanoma skin cancer, which we judged as moderate certainty owing to high heterogeneity. RCTs with low risk of bias suggested increased melanoma risk.Results for most outcomes were similar when we included all RCTs in the meta-analysis, regardless of risk of bias. Selenium supplementation did not reduce overall cancer incidence (RR 0.99, 95% CI 0.86 to 1.14; 5 studies, 21,860 participants) nor mortality (RR 0.81, 95% CI 0.49 to 1.32; 2 studies, 18,698 participants). Summary RRs for site-specific cancers showed limited changes compared with estimates from high-quality studies alone, except for liver cancer, for which results were reversed.In the largest trial, the Selenium and Vitamin E Cancer Trial, selenium supplementation increased risks of alopecia and dermatitis, and for participants with highest background selenium status, supplementation also increased risk of high-grade prostate cancer. RCTs showed a slightly increased risk of type 2 diabetes associated with supplementation. A hypothesis generated by the Nutritional Prevention of Cancer Trial - that individuals with low blood selenium levels could reduce their risk of cancer (particularly prostate cancer) by increasing selenium intake - has not been confirmed. As RCT participants have been overwhelmingly male (88%), we could not assess the potential influence of sex or gender.We included 15 additional observational cohort studies (70 in total; over 2,360,000 participants). We found that lower cancer incidence (summary odds ratio (OR) 0.72, 95% CI 0.55 to 0.93; 7 studies, 76,239 participants) and lower cancer mortality (OR 0.76, 95% CI 0.59 to 0.97; 7 studies, 183,863 participants) were associated with the highest category of selenium exposure compared with the lowest. Cancer incidence was lower in men (OR 0.72, 95% CI 0.46 to 1.14, 4 studies, 29,365 men) than in women (OR 0.90, 95% CI 0.45 to 1.77, 2 studies, 18,244 women). Data show a decrease in risk of site-specific cancers for stomach, colorectal, lung, breast, bladder, and prostate cancers. However, these studies have major weaknesses due to study design, exposure misclassification, and potential unmeasured confounding due to lifestyle or nutritional factors covarying with selenium exposure beyond those taken into account in multi-variable analyses. In addition, no evidence of a dose-response relation between selenium status and cancer risk emerged. Certainty of evidence was very low for each outcome. Some studies suggested that genetic factors might modify the relation between selenium and cancer risk - an issue that merits further investigation. AUTHORS' CONCLUSIONS: Well-designed and well-conducted RCTs have shown no beneficial effect of selenium supplements in reducing cancer risk (high certainty of evidence). Some RCTs have raised concerns by reporting a higher incidence of high-grade prostate cancer and type 2 diabetes in participants with selenium supplementation. No clear evidence of an influence of baseline participant selenium status on outcomes has emerged in these studies.Observational longitudinal studies have shown an inverse association between selenium exposure and risk of some cancer types, but null and direct relations have also been reported, and no systematic pattern suggesting dose-response relations has emerged. These studies suffer from limitations inherent to the observational design, including exposure misclassification and unmeasured confounding.Overall, there is no evidence to suggest that increasing selenium intake through diet or supplementation prevents cancer in humans. However, more research is needed to assess whether selenium may modify the risk of cancer in individuals with a specific genetic background or nutritional status, and to investigate possible differential effects of various forms of selenium.

The Epidemiology of Selenium and Human Cancer.

The relation between selenium and cancer has been one of the most hotly debated topics in human health over the last decades. Early observational studies reported an inverse relation between selenium exposure and cancer risk. Subsequently, randomized controlled trials showed that selenium supplementation does not reduce the risk of cancer and may even increase it for some types, including advanced prostate cancer and skin cancer. An increased risk of diabetes has also been reported. These findings have been consistent in the most methodologically sound trials, suggesting that the early observational studies were misleading. Other studies have investigated selenium compounds as adjuvant therapy for cancer. Though there is currently insufficient evidence regarding the utility and safety of selenium compounds for such treatments, this issue is worthy of further investigation. The study of selenium and cancer is complicated by the existence of a diverse array of organic and inorganic selenium compounds, each with distinct biological properties, and this must be taken into consideration in the interpretation of both observational and experimental human studies.

Improvements in emotion regulation following mindfulness meditation: Effects on depressive symptoms and perceived stress in younger breast cancer survivors.

OBJECTIVE: Mindfulness meditation reduces psychological distress among individuals with cancer. However, mechanisms for intervention effects have not been fully determined. This study tested emotion regulation strategies as mediators of intervention effects in a sample of younger women treated for breast cancer, a group at risk for psychological distress. We focused on two distinct strategies targeted by the intervention-rumination and self-kindness-and further examined the broader construct of mindfulness as a potential mediator. METHOD: Women (n = 71) with Stage 0-III breast cancer diagnosed at or before age 50 who had completed cancer treatment were randomly assigned to a 6-week mindfulness intervention or wait-list control group. Assessments occurred at study entry, postintervention, and a 3-month follow-up. RESULTS: In single mediator analyses, increases in self-kindness (CIB [-7.83, -1.93]), decreases in rumination (CIB [-5.05, -.31]), and increases in mindfulness (CIB [-6.58, -.82]) each mediated reductions in depressive symptoms from pre- to postintervention. Increases in self-kindness also mediated reductions in perceived stress (CIB [-5.37, -.62]) from pre- to postintervention, and increases in self-kindness (CIB [-5.67, -.22]) and in mindfulness (CIB [-5.51, -.16]) each mediated intervention effects on perceived stress from preintervention to 3-month follow-up. In multiple mediator analysis, only self-kindness mediated intervention effects on depressive symptoms from pre- to postintervention (CIB [-6.41, -.61]), and self-kindness and mindfulness together mediated intervention effects on perceived stress from preintervention to follow-up (CIB [-6.77, -.35]). CONCLUSIONS: Self-kindness played a consistent role in reducing distress in younger women with breast cancer. The efficacy of this understudied emotion regulation strategy should be evaluated in other clinical populations. (PsycINFO Database Record

A Phase I Dose Escalation Study Demonstrates Quercetin Safety and Explores Potential for Bioflavonoid Antivirals in Patients with Chronic Hepatitis C.

The hepatitis C virus (HCV) infects more than 180 million people worldwide, with long-term consequences including liver failure and hepatocellular carcinoma. Quercetin bioflavonoids can decrease HCV production in tissue culture, in part through inhibition of heat shock proteins. If quercetin demonstrates safety and antiviral activity in patients, then it could be developed into an inexpensive HCV treatment for third world countries or other affected populations that lack financial means to cover the cost of mainstream antivirals. A phase 1 dose escalation study was performed to evaluate the safety of quercetin in 30 untreated patients with chronic HCV infection and to preliminarily characterize quercetin's potential in suppressing viral load and/or liver injury. Quercetin displayed safety in all trial participants. Additionally, 8 patients showed a "clinically meaningful" 0.41-log viral load decrease. There was a positive correlation (r = 0.41, p = 0.03) indicating a tendency for HCV decrease in patients with a lower ratio of plasma quercetin relative to dose. No significant changes in aspartate transaminase and alanine transaminase were detected. In conclusion, quercetin exhibited safety (up to 5 g daily) and there was a potential for antiviral activity in some hepatitis C patients.

Mindfulness meditation for younger breast cancer survivors: a randomized controlled trial.

BACKGROUND: Premenopausal women diagnosed with breast cancer are at risk for psychological and behavioral disturbances after cancer treatment. Targeted interventions are needed to address the needs of this vulnerable group. METHODS: This randomized trial provided the first evaluation of a brief, mindfulness-based intervention for younger breast cancer survivors designed to reduce stress, depression, and inflammatory activity. Women diagnosed with early stage breast cancer at or before age 50 who had completed cancer treatment were randomly assigned to a 6-week Mindful Awareness Practices (MAPS) intervention group (n = 39) or to a wait-list control group (n = 32). Participants completed questionnaires before and after the intervention to assess stress and depressive symptoms (primary outcomes) as well as physical symptoms, cancer-related distress, and positive outcomes. Blood samples were collected to examine genomic and circulating markers of inflammation. Participants also completed questionnaires at a 3-month follow-up assessment. RESULTS: In linear mixed models, the MAPS intervention led to significant reductions in perceived stress (P = .004) and marginal reductions in depressive symptoms (P = .094), as well as significant reductions in proinflammatory gene expression (P = .009) and inflammatory signaling (P = .001) at postintervention. Improvements in secondary outcomes included reduced fatigue, sleep disturbance, and vasomotor symptoms and increased peace and meaning and positive affect (P < .05 for all). Intervention effects on psychological and behavioral measures were not maintained at the 3-month follow-up assessment, although reductions in cancer-related distress were observed at that assessment. CONCLUSIONS: A brief, mindfulness-based intervention demonstrated preliminary short-term efficacy in reducing stress, behavioral symptoms, and proinflammatory signaling in younger breast cancer survivors.

Associations between preterm birth, low birth weight, and postpartum health in a predominantly Hispanic WIC population.

OBJECTIVE: To describe the postpartum health of predominantly Hispanic participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and identify how health characteristics differ between mothers who delivered preterm or low birth weight infants and those who did not. DESIGN: Cross-sectional survey among postpartum WIC mothers. SETTING: Los Angeles and Orange Counties, CA. PARTICIPANTS: WIC participants within 1 year of delivery (n = 1,420). MAIN OUTCOME MEASURES: Postpartum health behaviors, health characteristics, and birth spacing intentions and behaviors. ANALYSIS: Frequencies of health characteristics were estimated using analyses with sample weights. Differences were assessed with chi-square and Fisher exact tests with Bonferroni correction for pairs of tests. RESULTS: Many women exhibited postpartum risk factors for future adverse health events, including overweight or obesity (62.3%), depressive symptoms (27.5%), and no folic acid supplementation (65.5%). Most characteristics did not differ significantly (P > .025) between mothers of preterm infants and full-term infants or between mothers of low birth weight and normal birth weight infants. CONCLUSIONS AND IMPLICATIONS: Despite few differences between postpartum characteristics of mothers who delivered preterm or low birth weight infants and those who did not, a high percentage of mothers had risk factors that need to be addressed. Current postpartum educational activities of WIC programs should be evaluated and shared.

Selenium for preventing cancer.

BACKGROUND: This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011).Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. OBJECTIVES: Two research questions were addressed in this review: What is the evidence for:1. an aetiological relation between selenium exposure and cancer risk in humans? and2. the efficacy of selenium supplementation for cancer prevention in humans? SEARCH METHODS: We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004. SELECTION CRITERIA: We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older). DATA COLLECTION AND ANALYSIS: For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs. MAIN RESULTS: We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0.69, 95% confidence interval (CI) 0.53 to 0.91, N = 8) and cancer mortality (OR 0.60, 95% CI 0.39 to 0.93, N = 6) associated with higher selenium exposure. Gender-specific subgroup analysis provided no clear evidence of different effects in men and women (P value 0.47), although cancer incidence was lower in men (OR 0.66, 95% CI 0.42 to 1.05, N = 6) than in women (OR 0.90, 95% CI 0.45 to 1.77, N = 2). The most pronounced decreases in risk of site-specific cancers were seen for stomach, bladder and prostate cancers. However, these findings have limitations due to study design, quality and heterogeneity that complicate interpretation of the summary statistics. Some studies suggested that genetic factors may modify the relation between selenium and cancer risk-a hypothesis that deserves further investigation.In RCTs, we found no clear evidence that selenium supplementation reduced the risk of any cancer (risk ratio (RR) 0.90, 95% CI 0.70 to 1.17, two studies, N = 4765) or cancer-related mortality (RR 0.81, 95% CI 0.49 to 1.32, two studies, N = 18,698), and this finding was confirmed when the analysis was restricted to studies with low risk of bias. The effect on prostate cancer was imprecise (RR 0.90, 95% CI 0.71 to 1.14, four studies, N = 19,110), and when the analysis was limited to trials with low risk of bias, the interventions showed no effect (RR 1.02, 95% CI 0.90 to 1.14, three studies, N = 18,183). The risk of non-melanoma skin cancer was increased (RR 1.44, 95% CI 0.95 to 1.17, three studies, N = 1900). Results of two trials-the Nutritional Prevention of Cancer Trial (NPCT) and the Selenium and Vitamin E Cancer Trial (SELECT)-also raised concerns about possible increased risk of type 2 diabetes, alopecia and dermatitis due to selenium supplements. An early hypothesis generated by NPCT that individuals with the lowest blood selenium levels at baseline could reduce their risk of cancer, particularly of prostate cancer, by increasing selenium intake has not been confirmed by subsequent trials. As the RCT participants were overwhelmingly male (94%), gender differences could not be systematically assessed. AUTHORS' CONCLUSIONS: Although an inverse association between selenium exposure and the risk of some types of cancer was found in some observational studies, this cannot be taken as evidence of a causal relation, and these results should be interpreted with caution. These studies have many limitations, including issues with assessment of exposure to selenium and to its various chemical forms, heterogeneity, confounding and other biases. Conflicting results including inverse, null and direct associations have been reported for some cancer types.RCTs assessing the effects of selenium supplementation on cancer risk have yielded inconsistent results, although the most recent studies, characterised by a low risk of bias, found no beneficial effect on cancer risk, more specifically on risk of prostate cancer, as well as little evidence of any influence of baseline selenium status. Rather, some trials suggest harmful effects of selenium exposure. To date, no convincing evidence suggests that selenium supplements can prevent cancer in humans.

Friend or foe? The current epidemiologic evidence on selenium and human cancer risk.

Scientific opinion on the relationship between selenium and the risk of cancer has undergone radical change over the years, with selenium first viewed as a possible carcinogen in the 1940s then as a possible cancer preventive agent in the 1960s-2000s. More recently, randomized controlled trials have found no effect on cancer risk but suggest possible low-dose dermatologic and endocrine toxicity, and animal studies indicate both carcinogenic and cancer-preventive effects. A growing body of evidence from human and laboratory studies indicates dramatically different biological effects of the various inorganic and organic chemical forms of selenium, which may explain apparent inconsistencies across studies. These chemical form-specific effects also have important implications for exposure and health risk assessment. Overall, available epidemiologic evidence suggests no cancer preventive effect of increased selenium intake in healthy individuals and possible increased risk of other diseases and disorders.

The need for a reassessment of the safe upper limit of selenium in drinking water.

Results of recent epidemiologic studies suggest the need to reassess the safe upper limit in drinking water of selenium, a metalloid with both toxicological and nutritional properties. Observational and experimental human studies on health effects of organic selenium compounds consumed through diet or supplements, and of inorganic selenium consumed through drinking water, have shown that human toxicity may occur at much lower levels than previously surmised. Evidence indicates that the chemical form of selenium strongly influences its toxicity, and that its biological activity may differ in different species, emphasizing the importance of the few human studies on health effects of the specific selenium compounds found in drinking water. Epidemiologic studies that investigated the effects of selenate, an inorganic selenium species commonly found in drinking water, together with evidence of toxicity of inorganic selenium at low levels in from in vitro and animal studies, indicate that health risks may occur at exposures below the current European Union and World Health Organization upper limit and guideline of 10 and 40 µg/l, respectively, and suggest reduction to 1 µg/l in order to adequately protect human health. Although few drinking waters are currently known to have selenium concentrations exceeding this level, the public health importance of this issue should not be overlooked, and further epidemiologic research is critically needed in this area.

Validity of child anthropometric measurements in the Special Supplemental Nutrition Program for Women, Infants, and Children.

INTRODUCTION: The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) serves 50% of infants and 25% of preschool-aged children in the United States and collects height and weight measurements from eligible children every 6 mo, making WIC data a valuable resource for studying childhood growth and obesity. We assessed the accuracy of measurements collected by WIC staff by comparing them to "gold standard" measurements collected by trained research staff. RESULTS: Intraclass correlation coefficients (ICCs) measuring agreement between WIC and research protocol measurements for height, weight, and BMI were 0.96, 0.99, and 0.93, respectively. Although WIC measurements overestimated height by 0.6 cm and weight by 0.05 kg on average, BMI was underestimated by only 0.15 kg/m(2) on average. WIC BMI percentiles classified children as overweight/obese vs. underweight/normal with 86% sensitivity and 92% specificity. DISCUSSION: We conclude that height, weight, and BMI measurements of children aged 2-5 y collected by trained WIC staff are sufficiently accurate for monitoring and research purposes. METHODS: At seven WIC clinics in southern California, 287 children aged 2-5 y measured for height and weight by WIC staff using WIC standard protocol were remeasured by research staff using a research protocol (duplicate measurements with shoes and outerwear removed were taken by trained personnel).