Dietary and blood selenium are inversely associated with the prevalence of stroke among Inuit in Canada

Effect of dietary selenium intake on CVD: a retrospective cohort study based on China Health and Nutrition Survey (CHNS) data

OBJECTIVE

We aimed to examine the association between dietary Se intake and CVD risk in Chinese adults.

DESIGN

This prospective cohort study included adults above 20 years old in the China Health and Nutrition Survey (CHNS), and they were followed up from 1997 to 2015 (n 16 030). Dietary data were retrieved from CHNS, and a 3-d, 24-h recall of food intake was used to assess the cumulative average intake of dietary Se, which was divided into quartiles. The Cox proportional hazards model was adopted to analyse the association between dietary Se intake and incident CVD risk.

SETTING

CHNS (1991, 1993, 1997, 2000, 2004, 2006, 2009, 2011 and 2015).

RESULTS

A total of 663 respondents developed CVD after being followed up for a mean of 9·9 years (median 9 years). The incidence of CVD was 4·3, 3·7, 4·6 and 4·0 per 1000 person-years across the quartiles of cumulative Se intake. After adjusting all potential factors, no significant associations were found between cumulative Se intake and CVD risk. No interactions were found between Se intake and income, urbanisation, sex, region, weight, hypertension and CVD risk.

CONCLUSION

We found no association between dietary Se and CVD.

Association Between Blood Selenium Levels and Stroke: A Study Based on the NHANES (2011-2018)

At present, the association between circulating selenium and stroke is still in dispute. Thus, this study aimed to ascertain the association with a larger sample size than the previous study, based on the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. In total, 13755 adults over the age of 20 years were included in our study. Multivariate logistic regression models were applied to analyze the correlation between blood selenium levels and stroke. The smooth curve fitting was performed to test the dose-response effects between blood selenium levels and stroke. After adjusting for all confounders, blood selenium levels were negatively associated with stroke (odds ratio [OR] = 0.57, 95% confidence interval [CI]: 0.37-0.87, P = 0.014). In the fully adjusted model, the highest tertile of blood selenium levels was negatively associated with stroke compared with the lowest tertile (OR = 0.70, 95% CI: 0.53-0.93, P for trend = 0.016). Moreover, the relationship between blood selenium levels and stroke was linear. In subgroup analyses, we observed that the test for interactions was significant for body mass index (BMI) and uric acid (P for interaction < 0.05). The negative relationship was stronger in participants with BMI 25-30 kg/m2 (OR = 0.23, 95% CI: 0.13-0.44, P < 0.001). Therefore, in American adults, the relationship between blood selenium levels and stroke was negative, with a linear tendency. In the future, a cohort study is warranted to further confirm this relationship.

Selenium's Role in Neuroprotection Against Stroke-Induced Inflammation

Acute ischemic stroke (AIS) incidence across the globe is on the rise, and the deleterious effects have not yet been improved with the use of current pharmaceuticals. Tissue plasminogen activator (tPA) has many risks and time constraints, making it difficult to use even as the standard treatment. Selenium deficiency and stroke incidence have a strong linear correlation among various populations. Using the ADME-Tox software, selenious acid absorption in brain cells, tissue, and interstitium was modeled under ischemic conditions to determine the bioavailability of selenium (Se) in the brain using various IV (intravenous) infusion doses. Additionally, we studied the cytotoxicity of selenious acid and selenourea on human dermal fibroblasts (HDF) and lung carcinoma cells (A549) to determine the overall growth and toxicity of different body cell lines to account for systemic side effects of IV infusion. Our data suggest that selenium can reach a dose-dependent concentration of 1.5µg/L or 250µg/L in brain cells within two hours of a one-time IV infusion, showing the ability to reach brain vasculature. Furthermore, cell viability can be maintained between 95% and 100% using 1nM and 0.5nM concentrations of selenious acid.

Association between the Composite Dietary Antioxidant Index and Stroke: A cross-sectional Study

The composite dietary antioxidant index (CDAI) is indeed a valuable nutritional tool used to evaluate the overall antioxidant capacity of an individual's daily food consumption. The CDAI was calculated from the intake of six antioxidant components in the diet, including vitamin A, vitamin C and vitamin E, carotenoids, selenium, and zinc. This study aimed to determine the association between CDAI and stroke. Utilizing data from the 2003-2018 NHANES dataset, CDAI was computed by summarizing the intake of six dietary antioxidants based on 24-hour dietary recall interviews. The relationship between CDAI and stroke was examined using multivariate logistic regression and restricted cubic spline analysis. This study ultimately included 39,432 participants, of whom 1,527 (3.87%) had a stroke. The multivariate logistic regression model 3 that fully adjusted all confounding variables showed a negative association between CDAI and stroke (OR = 0.97; 95% CI:0.95, 0.99). The highest tertile of CDAI saw a 23% drop in the prevalence of stroke compared to the lowest tertile (OR = 0.77; 95%CI: 0.64,0.92). Restricted cubic spline suggested that this negative correlation was nonlinear with an inflection point of -2.99. Subgroup analyses and interaction tests showed that this negative correlation was more applicable in patients with prediabetes (P < 0.05). There was a non-linear negative correlation between CDAI level and stroke prevalence, and this correlation was more significant in people with pre-diabetes. Appropriate CDAI levels may contribute to the management of stroke risk.

Association of Dietary Magnesium Intake with the Risk of Stroke among Adults

The relationship between dietary magnesium intake and the risk of stroke is controversial. This study aimed to examine the association of dietary magnesium intake with the risk of stroke among American adults.The relationship between dietary magnesium intake and the risk of stroke was analyzed using the National Health and Nutrition Examination Survey (NHANES) 2007-2018 data with 29,653 adults. The amount of magnesium from the diet was assessed by two 24-hour dietary recalls. Stroke outcomes were defined using the results of the self-reported questionnaires. The association between dietary magnesium intake and the risk of stroke was evaluated using logistic regression models and restricted cubic spline.In our study, an inverse association between dietary magnesium intake and the risk of stroke was found. For the highest versus lowest quartile of dietary magnesium intake, the multivariate-adjusted odds ratio (95% confidence interval) of stroke was 0.56 (0.36-0.86). The magnesium intake of women was negatively associated with stroke risk, but this negative association was not found in men. Then, the inverse association was statistically significant among the 40-59 year-old group. The results from the dose-response analysis show a linear relationship between dietary magnesium intake and the risk of stroke.Dietary magnesium intake was inversely associated with the risk of stroke, especially in women. Therefore, our study emphasizes the importance of appropriately increasing dietary magnesium intake.

Association between the intake of dietary n3 and n6 fatty acids and stroke in US adults: A cross-sectional study of NHANES 2007-2018

BACKGROUND

The association between the intake of dietary n3 and n6 fatty acids and the risk of stroke is subject to debate. The primary objective of the present research was to establish the correlation in a large sample of American adults.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018, the association of the intake of dietary n3 and n6 fatty acids with stroke events was analyzed in a sample of 29,459 adults. The intake of n3 and n6 fatty acids intake was assessed though two 24-h dietary recalls. Stroke outcomes were identified based on the responses provided in self-reported questionnaire. Logistic regression was fitted to evaluate the correlation of dietary n3, n6 fatty acids intake with stroke events.

RESULTS

Subjects in the highest tertile (T3) of dietary n3 (OR: 0.67, 95% CI: 0.49-0.93), n6 (OR: 0.65, 95% CI: 0.45-0.95) fatty acids intake were found to have obviously lower risk of stroke compared to those in the lowest tertile (T1), but the n6:n3 ratio was not found to be associated with a stroke event. Results from stratified analysis demonstrated that dietary n3 fatty acids had an inverse correlation of stroke in both male and female, but dietary n6 fatty acids only had this correlation in male. Moreover, findings were made that the interaction was significant in terms of age in the subgroup analysis, and the negative relationship between the intake of dietary n3 and n6 fatty acids and stroke event were particularly pronounced among participants aged ≥60.

CONCLUSIONS

The present results suggested that increased dietary n3, n6 fatty acids intake correlated with a lower risk of stroke.

Selenium, Stroke, and Infection: A Threefold Relationship; Where Do We Stand and Where Do We Go?

Stroke is currently the second most common cause of death worldwide and a major cause of serious long-term morbidity. Selenium is a trace element with pleotropic effects on human health. Selenium deficiency has been associated with a prothrombotic state and poor immune response, particularly during infection. Our aim was to synthesize current evidence on the tripartite interrelationship between selenium levels, stroke, and infection. Although evidence is contradictory, most studies support the association between lower serum selenium levels and stroke risk and outcomes. Conversely, limited evidence on the role of selenium supplementation in stroke indicates a potentially beneficial effect of selenium. Notably, the relationship between stroke risk and selenium levels is bimodal rather than linear, with higher levels of serum selenium linked to disturbances of glucose metabolism and high blood pressure, morbidities which are, in turn, substrates for stroke. Another such substrate is an infection, albeit forming a bidirectional relationship with both stroke and the consequences of impaired selenium metabolism. Perturbed selenium homeostasis leads to impaired immune fitness and antioxidant capacity, which both favor infection and inflammation; specific pathogens may also contend with the host for transcriptional control of the selenoproteome, adding a feed-forward loop to this described process. Broader consequences of infection such as endothelial dysfunction, hypercoagulation, and emergent cardiac dysfunction both provide stroke substrates and further feed-forward feedback to the consequences of deficient selenium metabolism. In this review, we provide a synthesis and interpretation of these outlined complex interrelationships that link selenium, stroke, and infection and attempt to decipher their potential impact on human health and disease. Selenium and the unique properties of its proteome could provide both biomarkers and treatment options in patients with stroke, infection, or both.

Association of habitually low intake of dietary selenium with new-onset stroke: A retrospective cohort study (2004-2015 China Health and Nutrition Survey)

Background

As an essential trace element in the body, selenium is associated with the development of many diseases. The purpose of this study was to explore the association between dietary selenium intake and new-onset stroke risk in Chinese adults.

Methods

Adults aged ≥18 years in the China Health and Nutrition Survey (CHNS) from 2004 to 2015 were enrolled. Participants were divided into five groups according to the quintile of dietary selenium intake: Q1 (≤ 29.80 μg/day), Q2 (29.80-38.53 μg/day), Q3 (38.53-47.23 μg/day), Q4 (47.23-60.38 μg/day), Q 5(>60.38 μg/day). Cox proportional-hazards model was used to explore the effect of dietary selenium on new-onset stroke. Restricted cubic spline (RCS) was used to visualize the dose-response relationship between dietary selenium and the risk of morbidity.

Results

A total of 11,532 subjects were included, and 271 (2.35%) of them developed stroke during a mean follow-up of 6.78 person-years. Compared with the lowest selenium intake group, the HR and 95%CI of stroke in the participants with selenium intake of Q2, Q3, Q4 and Q5 were: 0.85 (0.59, 1.21), 0.62 (0.42, 0.92), 0.43 (0.28, 0.68), 0.49 (0.30, 0.82), respectively. There was an L-shaped relationship between dietary selenium and stroke (nonlinear P-value = 0.0420). The HR and 95%CI of developing stroke was 0.75 (0.65, 0.87) in participants with selenium intake ≤ 60 μg/day.

Conclusions

The L-shaped negative association between dietary selenium and stroke in Chinese adults which indicated that dietary selenium should be improved to a certain level to prevent stroke.

The association between essential trace element mixture and atherosclerotic cardiovascular disease risk among Chinese community-dwelling older adults

The evidence about the association of the essential trace element (ETE) mixture with atherosclerotic cardiovascular disease (ASCVD) amongst older adults is limited. This study aims to evaluate the associations of single ETEs and the ETE mixture with the 10-year ASCVD risks and its predicting factors in Chinese community-dwelling older adults. A total of 607 community-dwelling older adults were included in this study. Blood levels of vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), and selenium (Se) were assessed by inductively coupled plasma mass spectrometry. The predicted 10-year ASCVD risk was calculated using the Prediction for ASCVD Risk in China (China-PAR) equations. Traditional linear regressions and Bayesian kernel machine regression (BKMR) were used to assess the associations of single ETEs and the ETE mixture with the 10-year ASCVD risks and its predicting factors such as systolic blood pressure (SBP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), diabetes, and waist circumference (WC). In linear regression models, blood Cr levels were negatively associated with the 10-year ASCVD risks after adjustment for covariates (β =  - 0.07, 95% CI =  - 0.11 ~  - 0.03); The 3th quartile (Q3) of Se levels was also associated with a lower 10-year ASCVD risks when compared with the lowest quartile (Q1) of Se levels (β_Q3 vs. _Q1: - 0.12, 95% CI =  - 0.22 ~  - 0.02). In BKMR models, the negative associations of Cr and Se with the 10-year ASCVD risks were observed. Higher blood levels of ETE mixture were associated with decreased 10-year ASCVD risks in a dose-response pattern, with Cr having the highest value of the posterior inclusion probability (PIP) within the mixture. Furthermore, a positive association between Cr and HDL-C and a negative association between Se and SBP were found in both linear regression and BKMR models. Cr and Se were negatively associated with the 10-year ASCVD risks, individually and as a mixture. ETE mixture showed a linear dose-response association with decreased 10-year ASCVD risks, with Cr being the most important component within the mixture. The negative association of the ETE mixture with the 10-year ASCVD risks may be attributed to Cr and Se, mainly mediated by HDL-C and SBP, respectively. Further cohort studies are needed to clarify this association.

The impact of mercury contamination on human health in the Arctic: A state of the science review

The 2021 Arctic Monitoring and Assessment Programme (AMAP) Mercury (Hg) Assessment is motivated by Arctic populations, and most notably Indigenous Peoples in the region, who are particularly vulnerable to Hg pollution. The objective of this review paper is to answer the following AMAP policy-relevant question: what is the human health impact of Hg pollution in the Arctic? In doing so, this state of the science review paper builds on information published 10 years ago in the last AMAP Hg assessment. The synthesized results demonstrate that: a) global influences (e.g., sources and transport pathways, biogeochemical processes, climate change, globalization) drive Hg exposures into human communities; b) Hg exposures are realized through dietary intake of certain country food items, and that new exposure science approaches are helping to deepen understandings; c) the nutritional and cultural benefits of country foods are immense, though a dietary transition is underway raising concerns over metabolic syndrome and broader issues of food security as well as cultural and social well-being; d) blood Hg measures are among the highest worldwide based on the results of human biomonitoring studies; e) Hg exposures are associated with adverse health outcomes across life stages (e.g., neurodevelopmental outcomes in young children to cardiovascular disease in adults); and f) risk communication needs to be balanced, targeted and clear, culturally appropriate, and be done collaboratively. These synthesized findings are particularly timely and policy-relevant given that the Minamata Convention entered into legal force worldwide in 2017 as a regulatory scheme to reduce the use and environmental release of Hg in order to protect human health and the environment. The Convention was influenced by health concerns raised by northern populations as indicated in the preamble text which makes reference to "the particular vulnerabilities of Arctic ecosystems and Indigenous communities".

A Bidirectional Mendelian Randomization Study of Selenium Levels and Ischemic Stroke

Background: Previous observational studies have shown that circulating selenium levels are inversely associated with ischemic stroke (IS). Our aims were to evaluate the causal links between selenium levels and IS, and its subtypes by Mendelian randomization (MR) analysis.

Methods: We used the two-sample Mendelian randomization (MR) method to determine whether the circulating selenium levels are causally associated with the risk of stroke. We extracted the genetic variants (SNPs) associated with blood and toenail selenium levels from a large genome-wide association study (GWAS) meta-analysis. Inverse variance-weighted (IVW) method was used as the determinant of the causal effects of exposures on outcomes.

Results: A total of 4 SNPs (rs921943, rs6859667, rs6586282, and rs1789953) significantly associated with selenium levels were obtained. The results indicated no causal effects of selenium levels on ischemic stroke by MR analysis (OR = 0.968, 95% CI 0.914–1.026, p = 0.269). Meanwhile, there was no evidence of a causal link between circulating selenium levels and subtypes of IS.

Conclusion: The MR study indicated no evidence to support the causal links between genetically predicted selenium levels and IS. Our results also did not support the use of selenium supplementation for IS prevention at the genetic level.

Selenium, Copper, Zinc Concentrations and Cu/Zn, Cu/Se Molar Ratios in the Serum of Patients with Acute Ischemic Stroke in Northeastern Poland-A New Insight into Stroke Pathophysiology

Background: In recent years, trace elements (TEs) have gained considerable attention in the course of treatment and diagnosis of ischemic stroke. The purpose of the conducted research was to determine the trace mineral status (Se, Cu, Zn, Cu/Zn ratio, and Cu/Se ratio) in patients with acute ischemic stroke compared to the population of healthy people in the northeastern region of Poland. Materials and methods: 141 patients with acute ischemic stroke (AIS) and 69 healthy control subjects were examined. The serum concentrations of mineral components were assessed by the atomic absorption spectrometry method. Clinical parameters were updated based on medical records. Results: The serum Se and Zn concentrations were significantly decreased (p < 0.0001; p < 0.0001) in patients with AIS compared with healthy control subjects. However, no significant differences were revealed in terms of the serum Cu concentration (p = 0.283). As expected, we found that the serum Cu/Zn and Cu/Se molar ratios were significantly higher (p = 0.001; p < 0.0001) in patients with AIS compared with healthy control subjects. Conclusions: Disturbed metal homeostasis is a significant contributor to AIS pathogenesis. Furthermore, marked disruption of the serum Cu/Zn and Cu/Se molar ratios could serve as a valuable indicator of AIS patients’ nutritional status and oxidative stress levels.

Sex difference in the association between plasma selenium and first stroke: a community-based nested case-control study

BACKGROUND

To date, there is no clearly defined association between plasma selenium levels and first stroke. We aimed to investigate the association between baseline plasma selenium and first stroke risk in a community-based Chinese population.

METHODS

Using a nested case-control study design, a total of 1255 first stroke cases and 1255 matched controls were analyzed. Participant plasma selenium concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS), and the association of plasma selenium with first stroke risk was estimated by conditional logistic regression models.

RESULTS

Overall, a non-linear negative association between plasma selenium and first total stroke and first ischemic stroke risks was found in males but not in females. Compared with participants with lower selenium levels (tertile 1-2, < 94.1 ng/mL), participants with higher selenium levels (tertile 3, ≥ 94.1 ng/mL) had significantly lower risks of first total stroke (OR 0.63; 95% CI 0.48, 0.83) and first ischemic stroke (OR 0.61; 95% CI 0.45, 0.83) in males but not in females with first total stroke (OR 0.92; 95% CI 0.69, 1.22) and first ischemic stroke (OR 0.89; 95% CI 0.65, 1.22). Furthermore, a stronger association between plasma selenium and first total stroke was found in males with higher vitamin E levels (≥ 13.5 μg/mL vs. < 13.5 μg/mL P-interaction = 0.007). No significant association was observed between plasma selenium and first hemorrhagic stroke risk in either males or females.

CONCLUSION

Our study indicated a significant, non-linear, negative association between plasma selenium and first stroke in males but not in females.

TRIAL REGISTRATION

ChiCTR1800017274 .

Relationship between the Circulating Selenium Level and Stroke: A Meta-Analysis of Observational Studies

Objective: To summarize the evidence regarding the relationship between the circulating selenium level and stroke based on observational studies.Methods: The electronic databases of PubMed, Web of Science, and Embase were searched up to October 2020, for observational studies concerning the association between the circulating selenium level and stroke. The pooled relative risk (RR) of stroke for the highest versus lowest category of the circulating selenium level and the weighted mean difference (WMD) of the circulating selenium level for stroke versus control subjects, as well as their corresponding 95% confidence interval (CI) were calculated.Results: A total of 11 articles with 12 observational studies were included (5 prospective cohort, 4 case-control, and 3 cross-sectional). The overall multivariable-adjusted RR demonstrated that the circulating selenium level was negatively associated with stroke (RR = 0.48, 95%CI: 0.24 to 0.94; p = 0.033), which was further confirmed in cross-sectional/case-control (RR = 0.24, 95%CI: 0.10 to 0.63; p = 0.003) and whole blood selenium (RR = 0.41, 95%CI: 0.26 to 0.65; p = 0.004) studies, rather than prospective cohort (RR = 0.88, 95%CI: 0.52 to 1.48; p = 0.62) and serum/plasma selenium (RR = 0.55, 95%CI: 0.22 to 1.40; p = 0.21) studies. Moreover, the overall combined WMD showed that the circulating selenium level in stroke was lower than that in control subjects (WMD = -0.16, 95%CI: -0.29 to -0.03; p = 0.017), which was further confirmed in whole blood selenium (WMD = -0.26, 95%CI: -0.44 to -0.08; p = 0.005), rather than serum/plasma selenium (WMD = -0.10, 95%CI: -0.27 to 0.07; p = 0.25) studies.Conclusions: Although our results suggest that the circulating selenium level is inversely associated with stroke, current evidence is still insufficient to conclude their definite association. More well-designed prospective cohort studies with detailed selenium biomarker specification are needed to elaborate the concerned issues further.

The Prevalence of Inorganic Mercury in Human Kidneys Suggests a Role for Toxic Metals in Essential Hypertension

The kidney plays a dominant role in the pathogenesis of essential hypertension, but the initial pathogenic events in the kidney leading to hypertension are not known. Exposure to mercury has been linked to many diseases including hypertension in epidemiological and experimental studies, so we studied the distribution and prevalence of mercury in the human kidney. Paraffin sections of kidneys were available from 129 people ranging in age from 1 to 104 years who had forensic/coronial autopsies. One individual had injected himself with metallic mercury, the other 128 were from varied clinicopathological backgrounds without known exposure to mercury. Sections were stained for inorganic mercury using autometallography. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used on six samples to confirm the presence of autometallography-detected mercury and to look for other toxic metals. In the 128 people without known mercury exposure, mercury was found in: (1) proximal tubules of the cortex and Henle thin loops of the medulla, in 25% of kidneys (and also in the man who injected himself with mercury), (2) proximal tubules only in 16% of kidneys, and (3) Henle thin loops only in 23% of kidneys. The age-related proportion of people who had any mercury in their kidney was 0% at 1-20 years, 66% at 21-40 years, 77% at 41-60 years, 84% at 61-80 years, and 64% at 81-104 years. LA-ICP-MS confirmed the presence of mercury in samples staining with autometallography and showed cadmium, lead, iron, nickel, and silver in some kidneys. In conclusion, mercury is found commonly in the adult human kidney, where it appears to accumulate in proximal tubules and Henle thin loops until an advanced age. Dysfunctions of both these cortical and medullary regions have been implicated in the pathogenesis of essential hypertension, so these findings suggest that further studies of the effects of mercury on blood pressure are warranted.

Quantitative selenium speciation in feed by enzymatic probe sonication and ion chromatography-inductively coupled plasma mass spectrometry

A rapid, sensitive and species preservative analytical method for the simultaneous determination of six selenium (Se) species has been developed. Enzymatic probe sonication (EPS) was investigated as a novel and alternative technology for the extraction of Se species from feed matrices and the results were compared with the conventional hot water extraction, enzymatic hydrolysis and sequential extraction. The critical parameters of EPS such as enzyme types, extraction time, temperature, ultrasonic power and sample/enzyme ratio were varied with control. The Se species were separated and quantitatively determined by ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS). Under current optimised conditions, six inorganic and organic Se species were completely separated within 15 min in a single chromatographic run. The spectral interferences from the argon plasma ⁴⁰Ar₂, ⁴⁰Ar³⁷Cl or ¹H⁷⁹Br were effectively removed by employing the kinetic energy discrimination (KED) mode. Quantitative extraction for total Se (>94.8%) and more than 89.0% for the sum of different Se chemical forms without species transformation were obtained in only 60 s by applying the EPS treatment using aqueous protease XIV. The limits of detection (LODs) and quantification (LOQs) for Se species were in the ranges of 0.21-0.56 µg kg^-1 and 0.69-1.87 µg kg^-1, respectively. The proposed method was successfully applied to the speciation of Se in several reference materials and feed samples collected from the markets and local farms.

Therapeutic potential of nutraceuticals to protect brain after stroke

Stroke leads to significant neuronal death and long-term neurological disability due to synergistic pathogenic mechanisms. Stroke induces a change in eating habits and in many cases, leads to undernutrition that aggravates the post-stroke pathology. Proper nutritional regimen remains a major strategy to control the modifiable risk factors for cardiovascular and cerebrovascular diseases including stroke. Studies indicate that nutraceuticals (isolated and concentrated form of high-potency natural bioactive substances present in dietary nutritional components) can act as prophylactic as well as adjuvant therapeutic agents to prevent stroke risk, to promote ischemic tolerance and to reduce post-stroke consequences. Nutraceuticals are also thought to regulate blood pressure, delay neurodegeneration and improve overall vascular health. Nutraceuticals potentially mediate these effects by their powerful antioxidant and anti-inflammatory properties. This review discusses the studies that have highlighted the translational potential of nutraceuticals as stroke therapies.

Drivers and health implications of the dietary transition among Inuit in the Canadian Arctic: a scoping review

OBJECTIVE

The current study undertook a systematic scoping review on the drivers and implications of dietary changes among Inuit in the Canadian Arctic.

DESIGN

A keyword search of peer-reviewed articles was performed using PubMed, Web of Science, CINAHL, Academic Search Premier, Circumpolar Health Bibliographic Database and High North Research Documents. Eligibility criteria included all full-text articles of any design reporting on research on food consumption, nutrient intake, dietary adequacy, dietary change, food security, nutrition-related chronic diseases or traditional food harvesting and consumption among Inuit populations residing in Canada. Articles reporting on in vivo and in vitro experiments or on health impacts of environmental contaminants were excluded.

RESULTS

A total of 162 studies were included. Studies indicated declining country food (CF) consumption in favour of market food (MF). Drivers of this transition include colonial processes, poverty and socio-economic factors, changing food preferences and knowledge, and climate change. Health implications of the dietary transition are complex. Micro-nutrient deficiencies and dietary inadequacy are serious concerns and likely exacerbated by increased consumption of non-nutrient dense MF. Food insecurity, overweight, obesity and related cardiometabolic health outcomes are growing public health concerns. Meanwhile, declining CF consumption is entangled with shifting culture and traditional knowledge, with potential implications for psychological, spiritual, social and cultural health and well-being.

CONCLUSIONS

By exploring and synthesising published literature, this review provides insight into the complex factors influencing Inuit diet and health. Findings may be informative for future research, decision-making and intersectoral actions around risk assessment, food policy and innovative community programmes.

Circulating Selenium Concentration Is Inversely Associated With the Prevalence of Stroke: Results From the Canadian Health Measures Survey and the National Health and Nutrition Examination Survey

Background

Observational studies have suggested that selenium (Se) may have beneficial effects against certain cardiovascular outcomes, with a possible U‐shaped association. We assessed the hypothesis that blood Se concentration might be inversely associated with the prevalence of stroke and the relationship would be nonlinear.

Methods and Results

Data collected from adult participants (aged ≥20 years) in the Canadian Health Measures Survey (CHMS 2007–2011, n=7065) and the US National Health and Nutrition Examination Survey (NHANES 2011–2012, n=5030) were analyzed. A total of 82 (1.16%) and 202 (4.02%) stroke cases were identified in CHMS and NHANES. Respondents with stroke had lower Se levels than those without stroke, with a mean difference of 16 μg/L and 12 μg/L for CHMS and NHANES, respectively. Respondents with high blood Se concentration (tertile 3) had a lower prevalence of stroke compared with those with low Se concentration (tertile 1). The adjusted odds ratios were 0.38 (95% CI: 0.15, 0.92) and 0.57 (95% CI: 0.31, 1.03) for CHMS and NHANES, respectively. A continuous decreasing trend of stroke with whole blood selenium was observed in CHMS, whereas the curve plateaued starting at 190 μg/L for NHANES, based on the cubic restricted spline regression. Sensitivity analysis using the serum and urinary Se concentrations demonstrates that our results were consistent across different selenium biomarkers.

Conclusions

We observed inverse cross‐sectional associations between whole blood Se and the prevalence of stroke in representative samples of the Canadian and the US population.

Selenoneine Ameliorates Hepatocellular Injury and Hepatic Steatosis in a Mouse Model of NAFLD

Selenoneine is a novel organic selenium compound markedly found in the blood, muscles, and other tissues of fish. This study aimed to determine whether selenoneine attenuates hepatocellular injury and hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD). Mice lacking farnesoid X receptor (FXR) were used as a model for fatty liver disease, because they exhibited hepatomegaly, hepatic steatosis, and hepatic inflammation. Fxr-null mice were fed a 0.3 mg Se/kg selenoneine-containing diet for four months. Significant decreases in the levels of hepatomegaly, hepatic damage-associated diagnostic markers, hepatic triglycerides, and total bile acids were found in Fxr-null mice fed with a selenoneine-rich diet. Hepatic and blood clot total selenium concentrations were 1.7 and 1.9 times higher in the selenoneine group than in the control group. A marked accumulation of selenoneine was found in the liver and blood clot of the selenoneine group. The expression levels of oxidative stress-related genes (heme oxygenase 1 (Hmox1), glutathione S-transferase alpha 1 (Gsta1), and Gsta2), fatty acid synthetic genes (stearoyl CoA desaturase 1(Scd1) and acetyl-CoA carboxylase 1 (Acc1)), and selenoprotein (glutathione peroxidase 1 (Gpx1) and selenoprotein P (Selenop)) were significantly decreased in the selenoneine group. These results suggest that selenoneine attenuates hepatic steatosis and hepatocellular injury in an NAFLD mouse model.

Association of circulating selenium concentration with dyslipidemia: Results from the NHANES

BACKGROUND

Observational studies have suggested that selenium levels might associate with the risk of cardio-metabolic diseases, but how circulating selenium is related to dyslipidemia remains inconclusive.

OBJECTIVES

To investigate the association of circulating selenium levels with lipid profiles and dyslipidemia among US adults.

METHODS

Using the data collected from the National Health and Nutrition Examination Survey (NHANES 1999-2006), we performed multivariate logistic regression to examine the association of circulating selenium levels (in quartiles) with total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and atherogenic index (AI).

RESULTS

We included 2903 adults (49.3 % male) (average age: 61.9) for analysis. Circulating selenium had non-linear association with TC, LDL-C, HDL-C, and AI (all p < 0.05). When comparing with the lowest quartile, subjects with the highest quartile of circulating selenium (>147.00 μg/L) had the higher odds of elevated TG (OR: 1.75, 95% CI = 1.14, 2.68), TC (OR: 2.47, 95% CI = 1.62, 3.76), LDL-C (OR: 2.52, 95% CI = 1.60, 3.96), non-HDL-C (OR: 2.17, 95% CI = 1.41, 3.33), AI (OR: 1.20, 95% CI = 0.73, 1.97) and low-HDL-C (OR: 2.10, 95% CI = 1.19, 3.72). Similar patterns were observed in subgroup analysis.

CONCLUSIONS

Higher circulating selenium levels had non-linear association with lipid profiles and the increased odds of dyslipidemia.

Selenium intake, status, and health: a complex relationship

Both selenium (Se) deficiency and excess are found in natural locations throughout the world, though Se excess can also be caused by supplementation with Se. Both have been associated with adverse health effects that have often been characterized by a U-shaped relationship. Some health effects, such as increased mortality, are associated with both low and high Se status. Certain people and populations are better able to tolerate low or high Se intake than others; there are a number of possible explanations for this fact. Firstly, it may relate to the presence of polymorphisms (SNPs) in genes that improve the ability to deal with a low or high Se intake. Secondly, high Se status, with apparent absence of toxicity and even beneficial effects, can be found in populations exposed to toxic elements that are known to interact with Se, forming complexes in some cases. Thirdly, beneficial and harmful effects of Se depend on Se dose and form (speciation); for instance, at a high dose, selenomethionine (SeMet) has toxic effects that are mediated by metabolism to selenols/selenolates that can redox-cycle, generate superoxide radicals and react with thiols/diselenides to produce selenyl sulphides/disulphides. Finally, it is possible that exposure to a high Se intake from birth or from a very young age may alter the composition of the gut microbiota in such a way that excess Se is more readily excreted, thus reducing its toxicity.

Mortality, growth and metabolic responses by 1H-NMR-based metabolomics of earthworms to sodium selenite exposure in soils

The rapid development of selenium-enriched agriculture leads to the accumulation of selenium in the soil, which has an adverse impact on terrestrial ecosystems. In the present study, the mortality, growth inhibition rate and metabolism of earthworms were examined to investigate the toxicological effects of sodium selenite (Na₂SeO₃) on earthworms (Eisenia fetida) after exposuring for 14 days (d). We used ¹H-NMR-based metabolomics to identify sensitive biomarkers and explored the metabolic responses of earthworms exposed to Na₂SeO₃. The mortality and growth inhibition rate of earthworms exposed to 70 and 90 mg/kg Na₂SeO₃ were significantly higher than the rate of control group. The LC₅₀ (the median lethal concentration) of Na₂SeO₃ was 57.4 mg/kg in this artificial soil test of E. fetida exposed to Na₂SeO₃ for 14 d. However, there was no significant differences when earthworms were exposed to different concentrations of Na₂SeO₃. The selected metabolic markers were ATP, lactic acid, leucine, alanine, valine, glycine, glutamic acid, lysine, α-glucose and betaine. Na₂SeO₃ affected the metabolic level of earthworms, as the percentage of metabolic markers in the earthworm changes when exposed to different concentrations of Na₂SeO₃. The metabolic disturbances were greater with increasing concentrations of Na₂SeO₃. The differential metabolic markers were significantly changed when exposed to Na₂SeO₃ comparing to those in the control group, affecting the tricarboxylic acid cycle process and breaking the metabolic balance. This study showed that Na₂SeO₃ had toxic effect on the growth and development of earthworms. In addition, this study provided a biochemical insights for the development of selenium-enriched agriculture.

Circulating Multiple Metals and Incident Stroke in Chinese Adults

Background and Purpose- Circulating metals synchronously reflect multiple metal exposures from both natural and anthropogenic sources, which may be linked with the risk of stroke. However, there is a lack of prospective studies investigating the associations of multiple metal exposures with incident stroke. Methods- We performed a nested case-control study within the ongoing Dongfeng-Tongji cohort launched in 2008. A total of 1304 incident stroke cases (1035 ischemic strokes and 269 hemorrhagic strokes) were prospectively identified by December 31, 2016, and matched to incident identity sampled controls according to age (within 1 year), sex, and blood sampling date (within 1 month). We determined the concentrations of 24 plasma metals and assessed the associations of plasma multiple metal concentrations with incident stroke using conditional logistic regression and elastic net model. Results- The average follow-up was 6.1 years. After adjusting for established risk confounders, copper, molybdenum, and titanium were significantly associated with higher risk of ischemic stroke (odds ratios according to per interquartile range increase, 1.29 [95% CI, 1.13-1.46], 1.19 [95% CI, 1.05-1.35], and 1.30 [95% CI, 1.07-1.59]), whereas rubidium and selenium were associated with lower risk of hemorrhagic stroke (odds ratios according to per interquartile range increase, 0.66 [95% CI, 0.50-0.87] and 0.68 [95% CI, 0.51-0.91]). The predictive plasma metal scores based on multiple metal exposures were significantly associated with higher risk of ischemic and hemorrhagic stroke (adjusted odds ratios according to per interquartile range increase, 1.37 [95% CI, 1.20-1.56] and 1.53 [95% CI, 1.16-2.01]). Conclusions- Plasma copper, molybdenum, and titanium were associated with higher risk of ischemic stroke, whereas plasma rubidium and selenium were associated with lower risk of hemorrhagic stroke. These findings may have important public health implications given the ever-increasing burden of stroke worldwide.