Vitamin C intake, circulating vitamin C and risk of stroke: a meta-analysis of prospective studies

Increased Vitamin C Intake Is Associated With Decreased Pancreatic Cancer Risk

Background

Patients with pancreatic cancer have an unfavorable 5-year survival rate of approximately 3% due to diagnosis occurring at advanced stages. Prior research has proposed vitamin C may have a therapeutic and preventative role in pancreatic cancer.

Methods

A Health Insurance Portability and Accountability Act (HIPAA) compliant national database was utilized to assess pancreatic cancer risk in patients with or without a history of vitamin C intake. The International Classification of Diseases (ICD) codes were used, specifically the International Classification of Diseases, 10th Edition (ICD-10) and International Classification of Diseases, Nineth Edition (ICD-9), between January 2010 and December 2020. Patients were matched, and statistical analyses were implemented. Chi-squared, logistic regression, and odds ratio were used to test for significance and to estimate relative risk.

Results

A total of 83,941 patients were identified as utilizing prescribed vitamin C. Subsequent matching by Charlson Comorbidity Index (CCI) score and age resulted in two groups of 50,384 patients. The incidence of pancreatic cancer was 243 (0.48%) in the group with a history of vitamin C intake compared to 442 (0.88%) in the control group. The difference was statistically significant by P < 3.174 × 10-14 with an odds ratio of 0.548 (95% confidence interval (CI): 0.468 - 0.641). Overall, patients without vitamin C prescription had an increased prevalence of pancreatic cancer throughout all ages and regions of the United States when compared to those with a vitamin C prescription. In addition, healthcare costs were higher in total for the control group when compared to the experimental group.

Conclusions

This retrospective cohort study found a statistically significant correlation between vitamin C and subsequent incidence of pancreatic cancer. Further studies are recommended to explore vitamin C's redox and cofactor activity in the context of preventing and possibly treating pancreatic cancer, as well as consider pancreatic cancer lifestyle risk factors such as smoking.

Global burden and cross-country inequalities in stroke and subtypes attributable to diet from 1990 to 2019

DATA SOURCES

The Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2019.

BACKGROUND

To describe burden, and to explore cross-country inequalities according to socio-demographic index (SDI) for stroke and subtypes attributable to diet.

METHODS

Death and years lived with disability (YLDs) data and corresponding estimated annual percentage changes (EAPCs) were estimated by year, age, gender, location and SDI. Pearson correlation analysis was performed to evaluate the connections between age-standardized rates (ASRs) of death, YLDs, their EAPCs and SDI. We used ARIMA model to predict the trend. Slope index of inequality (SII) and relative concentration index (RCI) were utilized to quantify the distributive inequalities in the burden of stroke.

RESULTS

A total of 1.74 million deaths (56.17% male) and 5.52 million YLDs (55.27% female) attributable to diet were included in the analysis in 2019.Between 1990 and 2019, the number of global stroke deaths and YLDs related to poor diet increased by 25.96% and 74.76% while ASRs for death and YLDs decreased by 42.29% and 11.34% respectively. The disease burden generally increased with age. The trends varied among stroke subtypes, with ischemic stroke (IS) being the primary cause of YLDs and intracerebral hemorrhage (ICH) being the leading cause of death. Mortality is inversely proportional to SDI (R = -0.45, p < 0.001). In terms of YLDs, countries with different SDIs exhibited no significant difference (p = 0.15), but the SII changed from 38.35 in 1990 to 45.18 in 2019 and the RCI showed 18.27 in 1990 and 24.98 in 2019 for stroke. The highest ASRs for death and YLDs appeared in Mongolia and Vanuatu while the lowest of them appeared in Israel and Belize, respectively. High sodium diets, high red meat consumption, and low fruit diets were the top three contributors to stroke YLDs in 2019.

DISCUSSION

The burden of diet-related stroke and subtypes varied significantly concerning year, age, gender, location and SDI. Countries with higher SDIs exhibited a disproportionately greater burden of stroke and its subtypes in terms of YLDs, and these disparities were found to intensify over time. To reduce disease burden, it is critical to enforce improved dietary practices, with a special emphasis on mortality drop in lower SDI countries and incidence decline in higher SDI countries.

From A to E: Uniting vitamins against stroke risk-A systematic review and network meta-analysis

BACKGROUND AND AIM

Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke.

METHODS

A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov, and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta-analysis. Furthermore, we ranked vitamins based on p-scores, facilitating a comparative assessment of their effectiveness in preventing stroke.

RESULTS

A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta-analysis, we found that vitamin A (RR: .81 [.72-.91]), vitamin B-complex (RR: .85 [.74-.97]), vitamin B6 (RR: 79 [.68-.92]), folate (RR: .86 [.75-.97]), vitamin C (RR: .77 [.70-.85]) and vitamin D (RR: .73 [.64-.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B2, vitamin B12, and vitamin E. Subsequent to network meta-analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p-score, with vitamin D (p-score = .91), vitamin C (p-score = .79), vitamin B6 (p-score = .70), vitamin A (p-score = .65), vitamin B-complex (p-score = .53), folate (p-score = .49), vitamin B2 (p-score = .39), vitamin E (p-score = .28), vitamin B12 (.13) and placebo (.10).

CONCLUSION

Our study has established noteworthy connections between vitamin A, vitamin B-complex, vitamin B6, folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well-designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.

Effects of H2S-donor ascorbic acid derivative and ischemia/reperfusion-induced injury in isolated rat hearts

Hydrogen sulfide (H2S), a gasotransmitter, plays a crucial role in vasorelaxation, anti-inflammatory processes and mitigating myocardial ischemia/reperfusion-induced injury by regulating various signaling processes. We designed a water soluble H2S-releasing ascorbic acid derivative, BM-164, to combine the beneficial cardiovascular and anti-inflammatory effects of H2S with the excellent water solubility and antioxidant properties of ascorbic acid. DPPH antioxidant assay revealed that the antioxidant activity of BM-164 in the presence of a myocardial tissue homogenate (extract) increased continuously over the 120 min test interval due to the continuous release of H2S from BM-164. The cytotoxicity of BM-164 was tested by MTT assay on H9c2 cells, which resulted in no cytotoxic effect at concentrations of 10 to 30 μM. The possible beneficial effects of BM-164 (30 µM) was examined in isolated 'Langendorff' rat hearts. The incidence of ventricular fibrillation (VF) was significantly reduced from its control value of 79 % to 31 % in the BM-164 treated group, and the infarct size was also diminished from the control value of 28 % to 14 % in the BM-164 treated group. However, coronary flow (CF) and heart rate (HR) values in the BM-164 treated group did not show significantly different levels in comparison with the drug-free control, although a non-significant recovery in both CF and HR was observed at each time point. We attempted to reveal the mechanism of action of BM-164, focusing on the processes of autophagy and apoptosis. The expression of key autophagic and apoptotic markers in isolated rat hearts were detected by Western blot analysis. All the examined autophagy-related proteins showed increased expression levels in the BM-164 treated group in comparison to the drug-free control and/or ascorbic acid treated groups, while the changes in the expression of apoptotic markers were not obvious. In conclusion, the designed water soluble H2S releasing ascorbic acid derivative, BM-164, showed better cardiac protection against ischemia/reperfusion-induced injury compared to the untreated and ascorbic acid treated hearts, respectively.

Sphingomyelin Metabolism Modifies Luminal A Breast Cancer Cell Line under a High Dose of Vitamin C

The role of sphingomyelin metabolism and vitamin C in cancer has been widely described with conflicting results ranging from a total absence of effect to possible preventive and/or protective effects. The aim of this study was to establish the possible involvement of sphingomyelin metabolism in the changes induced by vitamin C in breast cancer cells. The MCF7 cell line reproducing luminal A breast cancer and the MDA-MB-231 cell line reproducing triple-negative breast cancer were used. Cell phenotype was tested by estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 expression, and proliferation index percentage. Sphingomyelin was localized by an EGFP-NT-Lys fluorescent probe. Sphingomyelin metabolism was analyzed by RT-PCR, Western blotting and UFLC-MS/MS. The results showed that a high dose of vitamin C produced reduced cell viability, modulated cell cycle related genes, and changed the cell phenotype with estrogen receptor downregulation in MCF7 cell. In these cells, the catabolism of sphingomyelin was promoted with a large increase in ceramide content. No changes in viability and molecular expression were observed in MB231 cells. In conclusion, a high dose of vitamin C induces changes in the luminal A cell line involving sphingomyelin metabolism.

Dietary factors and hypertension risk in West Africa: a systematic review and meta-analysis of observational studies

BACKGROUND

Contrary to North America and Europe, the prevalence of hypertension is rising in West Africa. Although diet is implicated as a contributor to this trend, nutritional guidelines in West Africa are not tailored to address this concern. This study aimed to address this limitation by investigating dietary factors common to West Africa and evaluating their association with hypertension.

METHODS

PubMed, Scopus, Web of Science, and Medline were searched to identify studies that investigated diet and hypertension in West African adults. All meta-analyses used a generic inverse-variance random effects model, with subgroup analyses by age, BMI, and study location, and were performed in R.

RESULTS

Three thousand, two hundred ninety-eight studies were identified, of which 31 ( n  = 48 809 participants) satisfied inclusion criteria - all cross-sectional. Meta-analyses of the association between dietary factors and hypertension included dietary fat [odds ratio (OR) = 1.76; 95% confidence interval (95% CI) 1.44-2.14; P  < 0.0001], red meat (OR = 1.51; 95% CI: 1.04-2.18; P  = 0.03), junk-food (OR = 1.41; 95% CI: 1.19-1.67; P  < 0.0001), dietary salt (OR = 1.25; 95% CI: 1.12-1.40; P  < 0.0001), alcohol (OR = 1.17; 95% CI: 1.03-1.32; P  = 0.013), and 'fruits and vegetables' (OR = 0.80; 95% CI: 0.24-1.17; P  < 0.0001). Subgroup analyses suggested that 'fruit and vegetable' consumption is less protective in the elderly.

CONCLUSION

High consumption of dietary salt, red meat, dietary fat, junk food, and alcohol are associated with increased odds of hypertension, whereas high fruit and vegetable appear protective. This region-specific evidence will support the development of nutritional assessment tools for clinicians, patients, and researchers aiming to reduce hypertension in West Africa.

Neutrophil extracellular traps: A novel target for the treatment of stroke

Stroke is a threatening cerebrovascular disease caused by thrombus with high morbidity and mortality rates. Neutrophils are the first to be recruited in the brain after stroke, which aggravate brain injury through multiple mechanisms. Neutrophil extracellular traps (NETs), as a novel regulatory mechanism of neutrophils, can trap bacteria and secret antimicrobial molecules, thereby degrading pathogenic factors and killing bacteria. However, NETs also exacerbate certain non-infectious diseases by activating autoimmune or inflammatory responses. NETs have been found to play important roles in the pathological process of stroke in recent years. In this review, the mechanisms of NETs formation, the physiological roles of NETs, and the dynamic changes of NETs after stroke are summarized. NETs participate in stroke through various mechanisms. NETs promote the coagulation cascade and interact with platelets to induce thrombosis. tPA induces the degranulation of neutrophils to form NETs, leading to hemorrhagic transformation and thrombolytic resistance. NETs aggravate stroke by mediating inflammation, atherosclerosis and vascular injury. In addition, the regulation of NETs in stroke, the potential of NETs as biomarker and the treatment of stroke targeting NETs are discussed. The increasing evidences suggest that NETs may be a potential target for stroke treatment. Inhibition of NETs formation or promotion of NETs degradation plays protective effects in stroke. However, how to avoid the adverse effects of NETs-targeted therapy deserves further study. In summary, this review provides a reference for the pathogenesis, drug targets, biomarkers and drug development of NETs in stroke.

Frequent vegetable consumption is inversely associated with hypertension among indigenous Africans

AIMS

The relationship between vegetable consumption and hypertension occurrence remains poorly characterized in sub-Saharan Africa. This study assessed the association of vegetable consumption with odds of hypertension among indigenous Africans.

METHODS AND RESULTS

We harmonized data on prior vegetable consumption and hypertension occurrence (defined as one of the following conditions; systolic blood pressure ≥140 or diastolic blood pressure ≥90 mmHg or previous diagnosis or use of antihypertensive medications) from 16 445 participants across five African countries (Nigeria, South Africa, Kenya, Ghana and Burkina Faso) in the Stroke Investigative Research and Educational Network and Africa Wits-INDEPTH partnership for Genomic studies. Vegetable consumption (in servings/week) was classified as 'low' (<6). 'moderate' (6-11), 'sufficient' (12-29), and 'high' (≥30). Odds ratios (ORs) and 95% confidence interval (CI) of hypertension were estimated by categories of vegetable consumption (using 'low' consumption as reference), adjusting for sex, age in years, family history of cardiovascular diseases, education, smoking, alcohol use, physical inactivity, body mass index, diabetes mellitus and dyslipidaemia using logistic regressions at P < 0.05. The mean age of participants was 53.0 ( ± 10.7) years, and 7552 (45.9%) were males, whereas 7070 (42.9%) had hypertension. In addition, 6672(40.6%) participants had 'low' vegetable consumption, and 1758(10.7%) had 'high' vegetable consumption. Multivariable-adjusted OR for hypertension by distribution of vegetable consumption (using 'low' consumption as reference) were 1.03 (95% CI: 0.95, 1.12) for 'moderate' consumption; 0.80 (0.73, 0.88) for 'sufficient', and 0.81 (0.72, 0.92) for 'high' consumption, P-for-trend <0.0001.

CONCLUSION

Indigenous Africans who consumed at least 12 servings of vegetables per week were less likely to be found hypertensive, particularly among males and young adults.

Scurvy: Rare Orthopaedic Complications Associated with Multinutritional Deficiencies

Suboptimal nutrition can lead to deficiencies in micronutrients such as ascorbic acid (vitamin C), which can present with catastrophic neurological sequelae. Deficiencies of vitamin C, vitamin B3 (niacin) and zinc levels contribute to reduced bone density. Vitamin C associated vertebral fractures, although rare in adults, are still treatable if diagnosed early with a thorough clinical and nutritional history, and early supplementation. Radiological clues suggestive of scurvy-induced vertebral fractures can be diagnosed on plain X-ray and MRI spine imaging.

LEARNING POINTS

Although nutritional deficits like scurvy, pellagra and zinc deficiency are rare, early recognition and prompt treatment can prevent critical neurological sequelae.Clinical history including nutritional intake and associated patient symptoms are vital to diagnose scurvy-related vertebral fractures, which are treatable.It is important to note that scurvy can also present in an adult population.

Vitamin C Deficiency Exacerbates Dysfunction of Atherosclerotic Coronary Arteries in Guinea Pigs Fed a High-Fat Diet

Vitamin C (vitC) deficiency has been associated with an increased risk of cardiovascular disease; while several putative mechanistic links have been proposed, functional evidence supporting a causal relationship is scarce. In this study, we investigated how vitC deficiency affects coronary artery vasomotor function and the development of coronary atherosclerotic plaques in guinea pigs subjected to chronic dyslipidemia by a high-fat diet regime. Female Hartley guinea pigs were fed either a control (low-fat diet and sufficient vitC) (N = 8) or a high-fat diet with either sufficient (N = 8) or deficient (N = 10) vitC for 32 weeks. Guinea pigs subjected to the high-fat diet developed significant atherosclerotic plaques in their coronary arteries, with no quantitative effect of vitC deficiency. In isolated coronary arteries, vasomotor responses to potassium, carbachol, nitric oxide, or bradykinin were studied in a wire myograph. Carbachol, bradykinin, and nitric oxide mediated relaxation in the coronary arteries of the control group. While vasorelaxation to carbachol and nitric oxide was preserved in the two high-fat diet groups, bradykinin-induced vasorelaxation was abolished. Interestingly, bradykinin induced a significant contraction in coronary arteries from vitC-deficient guinea pigs (p < 0.05). The bradykinin-induced contraction was unaffected by L-NAME but significantly inhibited by both indomethacin and vitC, suggesting that, during vitC deficiency, increased release of arachidonic acid metabolites and vascular oxidative stress are involved in the constrictor effects mediated by bradykinin. In conclusion, the present study shows supporting evidence that poor vitC status negatively affects coronary artery function.

Current Evidence and Future Perspectives of the Best Supplements for Cardioprotection: Have We Reached the Final Chapter for Vitamins?

Cardiovascular disease (CVD), a broad-spectrum term comprising coronary artery disease, stroke, hypertension, and heart failure, presents as one of the most significant strains on global healthcare systems. Coronary artery disease, caused by atherosclerosis, has various modifiable risk factors such as dietary changes and exercise. Since these risk factors are found to be linked to oxidative stress and inflammations, the dietary supplementation with vitamins' role in treating and preventing the diseases has been of much debate. With various vitamins having anti-inflammatory and antioxidative properties, studies have explored their correlation with cardiovascular health. Therefore, this narrative review explores and evaluates the benefits and risks of all vitamin supplementations in patients with CVD and provides future recommendations.

Predictive role of modifiable factors in stroke: an umbrella review

BACKGROUND

A growing number of meta-analyses reviewed the existing associations between modifiable factors and stroke. However, the methodological quality of them and quality of evidence remain to be assessed by validated tools. Thus, this umbrella review was conducted to consolidate evidence from systematic reviews and meta-analyses of cohort studies investigating the association between modifiable factors and incidence of stroke.

METHODS

PubMed, Web of Science, Embase, Wanfang and China National Knowledge Infrastructure databases for systematic reviews and meta-analyses of cohort studies from inception until March 2021. Assess the methodological quality of systematic reviews 2 was used to evaluate the methodological quality of each included published meta-analysis. Excess significance test was used to investigate whether the observed number of studies (O) with nominally significant results ('positive' studies, p<0.05) was larger than the expected number of significant results (E). Statistically significant (p<0.05) associations were rated into five levels (strong, highly suggestive, suggestive, weak and no) using specific criteria. Sensitivity analyses were performed.

RESULTS

2478 records were identified through database searching. At last, 49 meta-analyses including 70 modifiable factors and approximately 856 801 stroke cases were included in the present review. The methodological quality of three meta-analyses was low, while others were critically low. Evidence of walking pace was strong. High suggestive evidence mainly included total meat, processes meat, chocolate, sodium, obesity, pulse pressure, systolic blood pressure, diastolic blood pressure, sleep duration and smoking. Suggestive evidence mainly included dietary approaches to stop hypertension (DASH) diet, vitamin C, magnesium, depression and particulate matter 2.5. After sensitivity analyses, evidence of DASH diet, magnesium and depression turned to weak. No publication bias existed, except only one study which could be explained by reporting bias.

DISCUSSION

Diet with rich macronutrients and micronutrients, healthy dietary patterns and favourable physical, emotional health and environmental management should be promoted to decrease the burden of stroke.

PROSPERO REGISTRATION NUMBER

CRD42021249921.

High-Dose Vitamin C for Cancer Therapy

In recent years, the idea that Vitamin C (Vit-C) could be utilized as a form of anti-cancer therapy has generated many contradictory arguments. Recent insights into the physiological characteristics of Vit-C, its pharmacokinetics, and results from preclinical reports, however, suggest that high-dose Vit-C could be effectively utilized in the management of various tumor types. Studies have shown that the pharmacological action of Vit-C can attack various processes that cancerous cells use for their growth and development. Here, we discuss the anti-cancer functions of Vit-C, but also the potential for the use of Vit-C as an epigenetic regulator and immunotherapy enhancer. We also provide a short overview of the current state of systems for scavenging reactive oxygen species (ROS), especially in the context of their influencing high-dose Vit-C toxicity for the inhibition of cancer growth. Even though the mechanisms of Vit-C action are promising, they need to be supported with robust randomized and controlled clinical trials. Moreover, upcoming studies should focus on how to define the most suitable cancer patient populations for high-dose Vit-C treatments and develop effective strategies that combine Vit-C with various concurrent cancer treatment regimens.

Tea consumption and cerebral hemorrhage risk: a meta-analysis

BACKGROUND

Tea contains many polyphenols with biological properties such as antithrombosis and antioxidation. Recent observational studies on tea consumption concerning cerebral hemorrhage risk have reported inconsistent results. This meta-analysis aimed to summarize the accumulated evidence on the association between tea consumption and cerebral hemorrhage risk.

METHODS

Web of Science, PubMed, Embase, and Scopus databases were searched to identify relevant studies through December 2021. Relative risks (RRs) or odds ratios (ORs) from observational studies were synthesized.

RESULTS

Ten studies involving over 721,827 participants were included. Higher tea consumption was correlated with a 23% (RR = 0.77; 95% CI 0.66-0.89) lower risk of cerebral hemorrhage. Subgroup meta-analyses indicated higher tea consumption was beneficial in preventing cerebral hemorrhage risk for green tea, alcohol-adjusted, fruit/vegetables-adjusted, and physical activity-adjusted subgroups, respectively (P < 0.01). Dose-response analysis indicated each one-cup (120 ml/cup) increment in tea or green tea intake/day was correlated with an average of 2% (RR = 0.98, 95% CI 0.976-0.990), or 6% (RR = 0.94; 95% CI 0.92-0.97) lower cerebral hemorrhage risk.

CONCLUSIONS

This study suggests that daily tea consumption is related to a lower risk of cerebral hemorrhage among adults. Green tea consumption appears to be more beneficial in preventing cerebral hemorrhage. Physical activity, fruit/vegetables, and alcohol may affect the relationship between tea consumption and hemorrhagic stroke. Future studies should investigate the interplay of tea with these factors.

Role of diet in stroke incidence: an umbrella review of meta-analyses of prospective observational studies

BACKGROUND

Stroke is one of the major challenges for the global healthcare system, which makes it necessary to explore the relationship between various modifiable factors and stroke risk. Recently, numerous meta-analyses of prospective observational studies have reported that dietary factors played a key role in the occurrence of stroke. However, the conclusions of previous studies have remained controversial and unclear. Accordingly, we conducted an umbrella review synthesizing and recalculating available evidence to assess the certainty of the associations between dietary factors and stroke.

METHODS

Relevant meta-analyses examining the associations between dietary factors and stroke were searched in PubMed and Embase databases up to September 1, 2021. For each eligible meta-analysis, two independent reviewers appraised the methodologic quality using the AMSTAR 2 criteria and estimated the summary effect size, 95% confidence intervals, 95% prediction intervals, heterogeneity between studies, and small-study effects. Moreover, we further assessed the associations between dietary factors and ischemic stroke as well as hemorrhagic stroke. Lastly, a set of pre-specified criteria was applied to qualitatively evaluate the epidemiological credibility of each dietary factor.

RESULTS

Overall, our umbrella review included 122 qualified meta-analyses for qualitative synthesis, involving 71 dietary factors related to food groups, foods, macronutrients, and micronutrients. Using the AMSTAR 2 criteria, 5 studies were assessed as high quality, 4 studies as moderate quality, and 113 studies as low or critically low quality. We identified 34 dietary factors associated with stroke occurrence, 25 dietary factors related to ischemic stroke, and 11 factors related to hemorrhagic stroke. Among them, high/moderate certainty epidemiological evidence demonstrated an inverse association between intake of fruits (RR: 0.90) and vegetables (RR: 0.92) and stroke incidence, but a detrimental association between red meat (RR: 1.12), especially processed red meat consumption (RR:1.17), and stroke incidence. Besides, the evidence of high/moderate certainty suggested that the intake of processed meat, fruits, coffee, tea, magnesium, and dietary fiber was associated with ischemic stroke risk, while consumption of tea, fruits, and vegetables was relevant to hemorrhagic stroke susceptibility.

CONCLUSIONS

Our study has reported that several dietary factors have a significant impact on stroke risk and offered a new insight into the relationship between dietary modification and stroke occurrence. Our results may provide an effective strategy for stroke prevention.

Therapeutic Opportunities and Delivery Strategies for Brain Revascularization in Stroke, Neurodegeneration, and Aging

Central nervous system (CNS) diseases, especially acute ischemic events and neurodegenerative disorders, constitute a public health problem with no effective treatments to allow a persistent solution. Failed therapies targeting neuronal recovery have revealed the multifactorial and intricate pathophysiology underlying such CNS disorders as ischemic stroke, Alzheimeŕs disease, amyotrophic lateral sclerosis, vascular Parkisonism, vascular dementia, and aging, in which cerebral microvasculature impairment seems to play a key role. In fact, a reduction in vessel density and cerebral blood flow occurs in these scenarios, contributing to neuronal dysfunction and leading to loss of cognitive function. In this review, we provide an overview of healthy brain microvasculature structure and function in health and the effect of the aforementioned cerebral CNS diseases. We discuss the emerging new therapeutic opportunities, and their delivery approaches, aimed at recovering brain vascularization in this context. SIGNIFICANCE STATEMENT: The lack of effective treatments, mainly focused on neuron recovery, has prompted the search of other therapies to treat cerebral central nervous system diseases. The disruption and degeneration of cerebral microvasculature has been evidenced in neurodegenerative diseases, stroke, and aging, constituting a potential target for restoring vascularization, neuronal functioning, and cognitive capacities by the development of therapeutic pro-angiogenic strategies.

Vitamin C intake and multiple health outcomes: an umbrella review of systematic reviews and meta-analyses

The purpose of this article was to assess the existing systematic reviews and meta-analyses for the association between vitamin C intake and multiple health outcomes. A total of 76 meta-analyses (51 papers) of randomised controlled trials and observational studies with 63 unique health outcomes were identified. Dose-response analysis showed that vitamin C intake was associated with reduced risk of all-cause mortality, cardiovascular disease (CVD), oesophageal cancer, gastric cancer, cervical cancer and lung cancer with an increment of 50-100 mg per day. Beneficial associations were also identified for respiratory, neurological, ophthalmologic, musculoskeletal, renal and dental outcomes. Harmful associations were found for breast cancer and kidney stones for vitamin C supplement intake. The benefits of vitamin C intake outweigh the disadvantages for a range of health outcomes. However, the recommendation of vitamin C supplements needs to be cautious. More prospective studies and well-designed randomised controlled trials (RCTs) are needed.

Circulating vitamin C and the risk of cardiovascular diseases: A Mendelian randomization study

BACKGROUND AND AIMS

The impact of vitamin C supplementation on the risk of cardiovascular diseases (CVDs) remains uncertain with inconsistent evidence obtained from observational studies and randomized clinical trials (RCTs). We aimed to assess possible causal associations of vitamin C with major CVD events as well as their risk factors using Mendelian randomization (MR) design.

METHODS AND RESULTS

Nine genetic variants associated with vitamin C at genome-wide significance (p < 5 × 10^-8) were used as instrumental variables to predict plasma vitamin C levels. The primary outcomes were coronary artery disease (Ncase = 122,733 and Ncontrol = 424,528), atrial fibrillation (Ncase = 60,620 and Ncontrol = 970,216), heart failure (Ncase = 47,309 and Ncontrol = 930,014), and ischemic stroke (Ncase = 40,585 and Ncontrol = 406,111). Several CVD risk factors were also evaluated in secondary analyses. Two-sample MR analyses were performed using the inverse variance weighted method, with several sensitivity analyses. Genetically determined higher levels of plasma vitamin C were not significantly associated with any of the four examined CVD events. Likewise, there is no convincing evidence for the associations between genetically determined vitamin C and CVD risk factors, including higher blood lipids, higher blood pressure, and abnormal body composition. Sensitivity analyses using different analytical approaches yielded consistent results. Additionally, MR assumptions did not seem to be violated.

CONCLUSION

This MR study does not support a causal protective role to circulate vitamin C levels on various types of CVD events. In combination with previous RCT results, our findings suggest that vitamin C supplementation to increase circulating vitamin C levels may not help in CVD prevention.

Dietary and supplemental antioxidant intake and risk of major adverse cardiovascular events in older men: The concord health and ageing in men project

BACKGROUND AND AIMS

The role of antioxidant intake in cardiovascular disease remains inconclusive. This study evaluates the association between antioxidant intake and the risk of major adverse cardiovascular events (MACE) among older Australian men.

METHODS AND RESULTS

794 men aged ≥75 years participated in the 3rd wave of the Concord Health and Ageing in Men Project. Dietary adequacy of antioxidant intake was assessed by comparing participants' intake of vitamins A, E, C and zinc to the Nutrient Reference Values (NRV) for Australia. Attainment of NRVs of antioxidants was categorised into a dichotomised variable 'inadequate' (meeting≤2 of 4 antioxidants) or 'adequate' (meeting≥3 of 4 antioxidants). The usage of antioxidant supplements was assessed. The outcome measure was MACE. The composite MACE endpoint was defined as having one of the following: death, myocardial infarction, ischemic stroke, congestive cardiac failure (CCF), and revascularization during the period of observation. There was no significant association between dietary (HR: 1.03, 95% CI: 0.71, 1.48) or supplemental antioxidant intake (HR: 1.10, 95% CI: 0.75, 1.63) and overall MACE. However, a significant association was observed between inadequate antioxidant intake and CCF (HR: 1.32; 95% CI: 1.16, 1.50). The lowest quartile of zinc intake (<11.00 mg/d) was significantly associated with CCF (HR 2.36; 95% CI: 1.04, 5.34). None of the other antioxidants were significantly associated with CCF or other MACE components.

CONCLUSION

Inadequate dietary antioxidant intake, particularly zinc, is associated with increased risk of CCF in older Australian men but not associated with overall MACE.

Assessment of Peripheral Blood Mononuclear Cells Senescence and Endothelial Dysfunction among Adults with High Cardiovascular Risk

BACKGROUND

Cardiovascular diseases (CVD) are one of the leading causes of mortality and morbidity worldwide. Biological aging has been associated with the occurrence of adverse cardiovascular outcomes; however, the underlying mechanism of this process remains unknown.

OBJECTIVES

This study sought to evaluate if peripheral blood mononuclear cell (PBMC) senescence and endothelial biomarkers could influence cardiovascular (CV) risk and be suitable markers for the early detection of cardiovascular diseases in adults.

METHODS

In this cross-sectional study patients free of CVD were classified as lower (n=32) and higher Interheart Risk (IHR) scores (n=28). PBMC senescence was assessed by estimating the telomerase activity (TA) and detecting the presence of senescent cells and endothelial dysfunction by estimating the concentration of nitrite and nitrate and of total antioxidant capacity (TAC). Statistical analysis was performed with SPSS version 16.0 (SPSS Inc., Chicago, IL). All p-values <0.05 were considered statistically significant.

RESULTS

PBMC senescence 0.95 [p-value = 0.0001; 95% CI (0.874-1.026)] was a significant predictor of patients with higher IHR scores with a cut-off value of 21.65 with a sensitivity and specificity of 92% and 88% respectively. PBMC senescence, nitrite and nitrate and TA were found to be independently associated with high IHR scores.

CONCLUSION

PBMC senescence, TA and nitrite, and nitrate status are suitable measures to predict high cardiovascular risk in adults with CV risk. Nevertheless, long-term follow-up studies are needed to confirm these findings. (Arq Bras Cardiol. 2021; 116(1):37-47).

Vitamin C and Cardiovascular Disease: An Update

The potential beneficial effects of the antioxidant properties of vitamin C have been investigated in a number of pathological conditions. In this review, we assess both clinical and preclinical studies evaluating the role of vitamin C in cardiac and vascular disorders, including coronary heart disease, heart failure, hypertension, and cerebrovascular diseases. Pitfalls and controversies in investigations on vitamin C and cardiovascular disorders are also discussed.

Multiple Health Benefits and Minimal Risks Associated with Vegetarian Diets

PURPOSE OF REVIEW

Understand the current prevalence, health benefits, and health risks of vegetarian diets.

RECENT FINDINGS

Since the publishing of the Adventist Health Study 2 in 2013, there have been several prospective diet studies demonstrating and challenging the health benefits and risks of the vegetarian diet. The definition of the vegetarian diet has become more specific over time and requires standardization for research purposes. Despite an uptrend in sales rates of plant-based foods per year, a 2018 Gallup poll showed overall stagnation of the percentage of self-reported vegetarians and vegans compared to percentages obtained 6 years prior. Compared to the Adventist Health Study, more recent vegetarian diet studies have demonstrated significant although smaller risk reductions for mortality in cardiovascular disease, cerebrovascular disease, diabetes mellitus, and chronic kidney disease. Recent studies have correlated certain food groups with early death or increased longevity. In addition, the vegetarian health risks of deficiencies of protein, omega-3 fatty acids, vitamin D, vitamin B12, iron, calcium, and zinc are explored.

Therapeutic treatment with vitamin C reduces focal cerebral ischemia-induced brain infarction in rats by attenuating disruptions of blood brain barrier and cerebral neuronal apoptosis

Stroke is a major public health problem and ranks third most common cause of death in adults worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury, mainly caused by oxidative/nitrosative stress injury, after revascularization therapy can result in worsening outcomes. For better clinical prognosis, more and more studies have focused on the pharmaceutical neuroprotective therapies against free radical damage. The impact of vitamin C (ascorbic acid) on oxidative stress-related diseases is moderate because of its limited oral bioavailability and rapid clearance. However, recent evidence of the clinical benefit of parenteral vitamin C administration has emerged, especially in critical care. In this study we demonstrated that parenteral administration of vitamin C significantly improved neurological deficits and reduced brain infarction and brain edema by attenuating the transient middle cerebral artery occlusion (tMCAO)-induced nitrosative stress, inflammatory responses, and the resultant disruptions of blood brain barrier and cerebral neuronal apoptosis. These results suggest that parenteral administration of vitamin C has potential as an adjuvant agent with intravenous thrombolysis or endovascular thrombectomy in acute treatment of ischemic stroke.

Association between adherence to the Japanese diet and all-cause and cause-specific mortality: the Japan Public Health Center-based Prospective Study

Purpose

The present study aimed to examine the association between adherence to the Japanese diet and the subsequent risk of all-cause and cause-specific mortality using a large-scale cohort from settings all over Japan.

Methods

We analyzed data from a cohort study of 92,969 Japanese adults aged 45–74 years, covering 11 public health center areas nationwide. We collected dietary information using a validated 147-item food frequency questionnaire. Adherence to the Japanese diet consisting of eight components (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, and green tea; low intake of beef and pork) was assessed using 8-item Japanese Diet Index (JDI8) score, with scores ranging from 0 to 8. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cause-specific mortality.

Results

During a median follow-up of 18.9 years, we documented 20,596 deaths. A higher JDI8 score was significantly associated with a lower risk for all-cause and cardiovascular disease (CVD) mortality. The multivariable-adjusted HR of all-cause and CVD mortality for the highest JDI8 score group (score of 6–8) versus the lowest JDI8 score group (score of 0–2) were 0.86 (95% CI 0.81–0.90, P trend < 0.001), and 0.89 (95% CI 0.80–0.99, P trend = 0.007), respectively.

Conclusions

Adhering to the Japanese diet, as assessed by the JDI8, was associated with a decreased risk of all-cause and CVD mortality among adults living in multiple areas across Japan.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02330-0) contains supplementary material, which is available to authorized users.

BKCa channel is a molecular target of vitamin C to protect against ischemic brain stroke

Epidemiological studies have demonstrated that vitamin C decreases the risk of stroke, which has generally been ascribed to its function as antioxidant and free radical scavenger. However, whether there is a defined molecular target for vitamin C on stroke is unknown. Utilizing middle cerebral artery occlusion (MCAO) in rats as a model for ischemic stroke, we demonstrated that long-term, low-dose administration of vitamin C prior to MCAO could exert significant neuroprotective effect on the brain damage. The long-term, low-dose vitamin C pretreated rats had decreased brain infarct size and decreased neurological deficit score compared with the vehicle or single high dose pretreated MCAO rats. Furthermore, electrophysiological experiments using patch clamp technique showed that vitamin C increased the whole-cell current of the large-conductance Ca²⁺-activated K⁺ (BK_Ca) channel. Moreover, vitamin C increased the open probability of the channel without change its amplitude. Importantly, blockade of the BK_Ca channels abolished the neuroprotective effect of vitamin C on MCAO. Therefore, this study shows that long-term, low-dose pretreatment with vitamin C could reduce MCAO-induced brain damage through activation of the BK_Ca channels, suggesting that the BK_Ca channel is a molecular target of vitamin C on stroke.

[Primary Prevention of Acute Stroke]

Primary Prevention of Acute Stroke Abstract. Strokes are frequent. Vascular risk factors are increasing the stroke risk. Most vascular risk factors are treatable. Their therapy is important in the primary prevention of stroke. According to the INTERSTROKE study, arterial hypertension, inactivity, overweight, dyslipidemia, smoking, unhealthy diet, cardiac pathologies such as major arrhythmia, diabetes mellitus, stress/depression and overconsumption of alcohol are the most important treatable vascular risk factors. In this article, we will also report on at present less well known treatable vascular risk factors such as sleep apnea, atheromatosis of the aortic arch and of arteries supplying the brain, migraine with aura and chronic inflammatory disorders and infections.

Comparison Effect of Tranexamic Acid (TA) and Tranexamic Acid Combined with Vitamin C (TXC) on Drainage Volume and Atrial Fibrillation Arrhythmia in Patients Undergoing Cardiac Bypass Surgery: Randomized Clinical Trial

BACKGROUND

Tranexamic acid and vitamin C are potent antifibrinolytic and oxidative stress agents that reduce blood loss and transfusion blood in cardiopulmonary bypass (CPB).

OBJECTIVES

The aim of this study was to evaluate the efficacy of tranexamic acid (TA) and tranexamic acid combined with vitamin C (TXC) on drainage volume (blood loss) and atrial fibrillation (AF) in patients undergoing cardiac bypass surgery in Gorgan, Shafa hospital, Iran.

METHODS

This study is a double-blind randomized clinical trial. A sample size of 120 candidates of cardiac bypass surgery were included in this prospective study. Patients were randomly assigned to treatments in two groups. In both groups, 50 mg/kg tranexamic acid was administered intravenously directly before sternotomy: group A (N = 58) patients received tranexamic acid (TA) only and group B (N = 62) tranexamic acid with vitamin C (TXC) half an hour before surgery and 2 g vitamin C with 100 mL 0.9% saline were injected. Subsequently, during 4 days after surgery, 1000 mg of vitamin C and 100 cc 0.9% saline was infused every day. Intraoperative and postoperative blood loss (volume of blood in the drain) and atrial fibrillation complications were recorded for 24 hours after the operation.

RESULTS

The patients who received vitamin C had less bleeding during operation and in the early hours post-operation. Patients in (TA) group had mean drainage of 34.41 milliliter more than patients in (TXC) group (P < 0.001). Chi-square test showed that arrhythmia (AF) condition was the same in the two groups during 14 times of study (four times during operation and ten times up to 24 hours after the operation), and AF arrhythmia in the two groups was less than 5%.

CONCLUSIONS

In this study tranexamic acid with vitamin C have a positive effect on the amount of drainage (blood loss) and there was no significant difference in the incidence of AF between two groups.

Overview of Meta-Analyses: The Impact of Dietary Lifestyle on Stroke Risk

A stroke is one of the most prevalent cardiovascular diseases worldwide, both in high-income countries and in medium and low-medium income countries. The World Health Organization's (WHO) report on non-communicable diseases (NCDs) indicates that the highest behavioral risk in NCDs is attributable to incorrect nutrition. The objective of our work is to present an overview of meta-analyses that have investigated the impact of different foods and/or drinks in relationship with the risk of stroke events (ischemic/hemorrhagic). The papers to be included in the overview were found in MEDLINE, EMBASE, Scopus, Clinicaltrials.gov, Web of Science, and Cochrane Library and were selected according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) flow chart. Quality assessment were made according to the AMSTAR 2 scale. This overview shows that all primary studies came from countries with high income levels. This evidence shows that many countries are not represented. Therefore, different lifestyles, ethnic groups, potentially harmful or virtuous eating habits are not reported. It is important to underline how the choose of foods may help reduce the risk of cardiovascular diseases and stroke in particular.

SVCT2 Promotes Neural Stem/Progenitor Cells Migration Through Activating CDC42 After Ischemic Stroke

Ischemic stroke is one of the most leading diseases causing death/long-term disability worldwide. Activating endogenous neural stem/progenitors cells (NSPCs), lining in the subventricular zone (SVZ) and dentate gyrus, facilitates injured brain tissue recovery in both short and long-term experimental settings. While, only a few proliferated NSPCs migrate toward the lesions to enhance endogenous repair after ischemia. Here, the results indicated that the functional recovery was evidently improved and the infarct volume was significantly reduced with ascorbic acid (AA) treatment in a dose-dependent manner from 125 to 500 mg/Kg, and the suitable therapeutic concentration was 250 mg/Kg. The possible mechanism might be due to activating sodium-vitamin C cotransporter 2 (SVCT2), which was down-regulated in SVZ after ischemia. Furthermore, immunostaining images depicted the number of migrated NSPCs from SVZ were significantly increased with 250 mg/Kg AA treatment or SVCT2 overexpression under the physiological and pathological condition in vivo. Besides, the data also represented that 250 mg/Kg AA or SVCT2 overexpression facilitated NSPCs migration via promoting F-actin assembling in the manner of up-regulating CDC42 expression using oxygen-glucose deprivation in vitro. Collectively, the present study indicates that SVCT2 promotes NSPCs migration through CDC42 activation to facilitate F-actin assembling, which enlarges the therapeutic scope of AA and the role of SVCT2 in NSPCs migration after brain injury.

Dietary and circulating vitamin C, vitamin E, β-carotene and risk of total cardiovascular mortality: a systematic review and dose-response meta-analysis of prospective observational studies

OBJECTIVE

The present review aimed to quantify the association of dietary intake and circulating concentration of major dietary antioxidants with risk of total CVD mortality.

DESIGN

Systematic review and meta-analysis.

SETTING

Systematic search in PubMed and Scopus, up to October 2017.ParticipantsProspective observational studies reporting risk estimates of CVD mortality across three or more categories of dietary intakes and/or circulating concentrations of vitamin C, vitamin E and β-carotene were included. A random-effects meta-analysis was conducted.

RESULTS

A total of fifteen prospective cohort studies and three prospective evaluations within interventional studies (320 548 participants and 16 974 cases) were analysed. The relative risks of CVD mortality for the highest v. the lowest category of antioxidant intakes were as follows: vitamin C, 0·79 (95 % CI 0·68, 0·89; I 2=46 %, n 10); vitamin E, 0·91 (95 % CI 0·79, 1·03; I 2=51 %, n 8); β-carotene, 0·89 (95 % CI 0·73, 1·05; I 2=34 %, n 4). The relative risks for circulating concentrations were: vitamin C, 0·60 (95 % CI 0·42, 0·78; I 2=65 %, n 6); α-tocopherol, 0·82 (95 % CI 0·76, 0·88; I 2=0 %, n 5); β-carotene, 0·68 (95 % CI 0·52, 0·83; I 2=50 %, n 6). Dose-response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of CVD mortality than dietary intakes.

CONCLUSIONS

The present meta-analysis demonstrates that higher vitamin C intake and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of CVD mortality.

Vitamin E intake and risk of stroke: a meta-analysis

Findings from observational studies on the associations between vitamin E intake and stroke risk remain controversial, and the dose–response relationship between vitamin E intake and risk of stroke remains to be determined. We conducted a meta-analysis of prospective studies aiming to clarify the relationships between vitamin E intake and risk of stroke. Relevant studies were identified by searching online databases through to June 2018. We computed summary relative risks (RR) with corresponding 95 % CI. Among 3156 articles retrieved from online databases and relevant bibliographies, nine studies involving 3284 events and 220 371 participants were included in the final analyses. High dietary vitamin E intake was inversely associated with the risk of overall stroke (RR=0·83, 95 % CI 0·73, 0·94), and with the risk of stroke for individuals who were followed-up for <10 (RR=0·84, 95 % CI 0·72, 0·91). There was a non-linear association between dietary vitamin E intake and stroke risk (P=0·0249). Omission of any single study did not alter the summary result. In conclusion, this meta-analysis suggests that there is a significant inverse relationship between dietary vitamin E intake and stroke risk. This meta-analysis provides evidence that a higher dietary vitamin E intake is associated with a lower stroke risk.

Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies

Background

High dietary intake or blood concentrations (as biomarkers of dietary intake) of vitamin C, carotenoids, and vitamin E have been associated with reduced risk of cardiovascular disease, cancer, and mortality, but these associations have not been systematically assessed.

Objective

We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of vitamin C, carotenoids, and vitamin E in relation to these outcomes.

Design

We searched PubMed and Embase up to 14 February 2018. Summary RRs and 95% CIs were calculated with the use of random-effects models.

Results

Sixty-nine prospective studies (99 publications) were included. The summary RR per 100-mg/d increment of dietary vitamin C intake was 0.88 (95% CI: 0.79, 0.98, I2 = 65%, n = 11) for coronary heart disease, 0.92 (95% CI: 0.87, 0.98, I2 = 68%, n = 12) for stroke, 0.89 (95% CI: 0.85, 0.94, I2 = 27%, n = 10) for cardiovascular disease, 0.93 (95% CI: 0.87, 0.99, I2 = 46%, n = 8) for total cancer, and 0.89 (95% CI: 0.85, 0.94, I2 = 80%, n = 14) for all-cause mortality. Corresponding RRs per 50-μmol/L increase in blood concentrations of vitamin C were 0.74 (95% CI: 0.65, 0.83, I2 = 0%, n = 4), 0.70 (95% CI: 0.61, 0.81, I2 = 0%, n = 4), 0.76 (95% CI: 0.65, 0.87, I2 = 56%, n = 6), 0.74 (95% CI: 0.66, 0.82, I2 = 0%, n = 5), and 0.72 (95% CI: 0.66, 0.79, I2 = 0%, n = 8). Dietary intake and/or blood concentrations of carotenoids (total, β-carotene, α-carotene, β-cryptoxanthin, lycopene) and α-tocopherol, but not dietary vitamin E, were similarly inversely associated with coronary heart disease, stroke, cardiovascular disease, cancer, and/or all-cause mortality.

Conclusions

Higher dietary intake and/or blood concentrations of vitamin C, carotenoids, and α-tocopherol (as markers of fruit and vegetable intake) were associated with reduced risk of cardiovascular disease, total cancer, and all-cause mortality. These results support recommendations to increase fruit and vegetable intake, but not antioxidant supplement use, for chronic disease prevention.

Association of plasma vitamin C concentration to total and cause-specific mortality: a 16-year prospective study in China

BACKGROUND

Vitamin C insufficiency occurs across many countries and has been hypothesised to increase risk of various diseases. Few prospective studies with measured circulating vitamin C have related deficiency to disease mortality, particularly in low-income and middle-income countries.

METHODS

We randomly selected 948 subjects (473 males and 475 females) aged 53-84 years from a Chinese cohort and measured meta-phosphoric acid-preserved vitamin C concentrations in plasma samples collected in 1999-2000. A total of 551 deaths were accrued from sample collection through 2016, including 141 from cancer, 170 from stroke and 174 from heart diseases. Vitamin C was analysed using season-specific quartiles, as a continuous variable and as a dichotomous variable based on sufficiency status (normal >28 µmol/L vs low ≤28 µmol/L). HRs and 95% CIs were estimated using Cox proportional hazards models.

RESULTS

We found significant inverse associations between higher plasma vitamin C concentrations and total mortality in quartile (HR_{Q4 vs Q1}0.75, 95% CI 0.59 to 0.95), continuous (HR_q20umol/L0.90, 95% CI 0.82 to 0.99) and dichotomous analyses (HR_{normal-vs-low}0.77, 95% CI 0.63 to 0.95). We observed significant lower risks of heart disease (p_{trend-by-quantile}=0.03) and cancer deaths (p_{global-across-quantile}=0.04) for higher vitamin C, whereas the association was attenuated for stroke in adjusted models. Similar inverse associations were found when comparing normal versus low vitamin C for heart disease (HR_{normal-vs-low}0.62, 95% CI 0.42 to 0.89).

CONCLUSION

In this long-term prospective Chinese cohort study, higher plasma vitamin C concentration was associated with lower total mortality, heart disease mortality and cancer mortality. Our results corroborate the importance of adequate vitamin C to human health.

Vitamin C Deficiency, High-Sensitivity C-Reactive Protein, and Cardiac Event-Free Survival in Patients With Heart Failure

BACKGROUND

Vitamin C is related to lower levels of high-sensitivity C-reactive protein (hsCRP), an inflammatory biomarker that predicts cardiovascular disease. Whether vitamin C deficiency is associated with hsCRP and cardiac events in heart failure (HF) patients has not been examined.

PURPOSE

The aim of this study is to determine the relationships among vitamin C intake, serum levels of hsCRP, and cardiac events.

METHODS

A total of 200 HF patients completed a 3-day food diary to determine vitamin C deficiency and provided blood to measure serum levels of hsCRP. Patients were followed for 2 years to obtain data on cardiac event-free survival. Moderation analyses with hierarchical logistic and Cox regressions were used for the data analysis.

RESULTS

Seventy-eight patients (39%) had vitamin C deficiency and 100 (50%) had an hsCRP level higher than 3 mg/L. Vitamin C deficiency was associated with an hsCRP level higher than 3 mg/L in the hierarchical logistic regression (odds ratio, 2.40; 95% confidence interval, [1.13-5.10]; P = .023). Vitamin C deficiency (hazard ratio, 1.68; 95% CI, 1.05-2.69, P = .029) and hsCRP level higher than 3 mg/L (hazard ratio, 1.79; 95% CI, 1.07-3.01; P = .027) predicted shorter cardiac event-free survival in hierarchical Cox regression. The interaction of hsCRP level higher than 3 mg/L and vitamin C deficiency produced a 2.3-fold higher risk for cardiac events (P = .002) in moderation analysis. Higher level of hsCRP predicted shorter cardiac event-free survival only in patients with vitamin C deficiency (P = .027), but not in those with vitamin C adequacy.

CONCLUSION

Vitamin C deficiency moderated the relationship between inflammation and cardiac events in patients with HF. Future study is required to determine whether adequate intake of vitamin C could play a protective role against the impact of inflammation on cardiac events in HF patients.

Vegetarian Dietary Patterns and Cardiovascular Disease

Cardiovascular (CV) disease (CVD) is the leading global cause of mortality, being responsible for 46% of non-communicable disease deaths. It has been estimated that about 85.6 million Americans are living with some form of CVD, which continues to rise. Healthy lifestyle choices may reduce the risk of myocardial infarction by >80%, with nutrition playing a key role. Vegetarian dietary patterns reduce CVD mortality and the risk of coronary heart disease (CHD) by 40%. Plant-based diets are the only dietary pattern to have shown reversal of CHD. Additionally, evidence suggests benefits of vegetarian dietary patterns in both the prevention and the treatment of heart failure and cerebrovascular disease. Plant-based diets are associated with lower blood pressure, lower blood lipids, and reduced platelet aggregation than non-vegetarian diets and are beneficial in weight management, reduce the risk of developing metabolic syndrome, and type 2 diabetes. They have also been shown an effective treatment method in diabetes management. Well planned vegetarian diets provide benefits in preventing and reversing atherosclerosis and in decreasing CVD risk factors and should be promoted through dietary guidelines and recommendations.

Integrative Medicine and Cardiovascular Disorders

Integrative medicine (IM) has developed an increasingly significant role in health care worldwide, including cardiovascular diseases (CVD). This review describes the commonly used IM in CVD, with particular attention placed with dietary supplements and mind-body therapies. More rigorous research continues to be needed to determine the mechanisms and efficacy of IM cardiovascular morbidity and mortality. Health care providers will need to develop skills in open communication and nonjudgmental dialogue around IM use in discussing treatment plans with their patients.

Diet and primary prevention of stroke: Systematic review and dietary recommendations by the ad hoc Working Group of the Italian Society of Human Nutrition

BACKGROUND AND AIMS

To systematically review the latest evidence on established and emerging nutrition-related risk factors for incidence of and mortality from total, ischemic and haemorrhagic strokes. The present review was conducted in the framework of the work carried out through 2015 and 2016 for the preparation of the Italian Guidelines for the Prevention and Treatment of Stroke, 8th Edition, by ISO-SPREAD (Italian Stroke Organization and the Stroke Prevention and Educational Awareness Diffusion).

METHODS AND RESULTS

Systematic review of articles focused on primary prevention of stroke published between January 2013 to May 2016 through an extensive search of the literature using MEDLINE/PUBMED, EMBASE and the Cochrane Library. Articles were ranked according to the SIGN methodology while the GRADE system was used to establish the strength of recommendations. As a result of our literature search, we examined 87 meta-analyses overall (mainly of prospective studies), a few isolated more recent prospective studies not included in the meta-analyses, and a smaller number of available randomized controlled trials and case-control studies. Based on the analysis of the above articles, 36 Syntheses of the available evidence and 36 Recommendations were eventually prepared. The present document was developed by organizing the available evidence into three individual areas (nutrients, food groups and dietary patterns) to provide a systematic and user-friendly overview of the available evidence on the relationship between nutrition and primary prevention of stroke. Yet analysis of foods and food patterns allowed translating the information about nutrients in a tool more amenable to use in daily life also in the light of the argument that people eat foods rather than nutrients.

CONCLUSIONS

The present literature review and dietary recommendations provide healthcare professionals and all interested readers with a useful overview for the reduction of the risk of total, ischemic and haemorrhagic stroke through dietary modifications.

Systemic oxidoreductive balance and vascular function in individuals without clinical manifestation of atherosclerosis

Introduction

Endothelial dysfunction is recognized as the earliest disorder in the development of atherosclerosis, in the pathogenesis of which oxidative stress plays a crucial role. The aim of this study was to determine the relationships between non-invasive parameters of vascular dysfunction and oxidative stress.

Material and methods

Forty-eight individuals without clinical manifestation of atherosclerosis were studied. The plasma concentrations of the following were determined in all 48 subjects: retinol, ascorbic acid, α-tocopherol and uric acid, as well as the products of oxidative DNA damage repair: 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in blood leukocytes and urine, and 8-oxo-7,8-dihydroguanine (8-oxoGua) in urine. The following parameters of vascular dysfunction were also examined: flow- (FMD) and nitroglycerin- (NMD) mediated dilatation of the brachial artery, pulse pressure (PP), distensibility coefficient (DC), pulsation (PI) and resistance (RI) index, carotid intima-media thickness (cIMT), and ankle-brachial index (ABI).

Results

Individuals with an FMD value of ≥ 8.8% had significantly higher blood concentrations of antioxidative vitamins and lower concentrations of 8-oxodG in their urine and blood leukocytes than their counterparts. Blood concentration of alpha-tocopherol or ascorbic acid positively correlated with FMD, PI, RI, DC and ABI and negatively with PP and cIMT. The reverse was the case for 8-oxodG in urine and leukocytes. In multiple regression analysis, markers of oxidative DNA damage positively determined the variance in PP and ABI.

Conclusions

In persons without clinical manifestation of atherosclerosis, oxidative stress was an independent factor associated with vascular wall dysfunction, and a better predictor than smoking and blood concentrations of glucose, lipids and creatinine.

Multivitamin use and risk of stroke incidence and mortality amongst women

BACKGROUND AND PURPOSE

Few studies have examined the association between multivitamin use and the risk of stroke incidence and mortality, and the results remain inconclusive as to whether multivitamins are beneficial.

METHODS

The associations between multivitamin use and the risk of incident stroke and stroke mortality were prospectively examined in 86 142 women in the Nurses' Health Study, aged 34-59 years and free of diagnosed cardiovascular disease at baseline. Multivitamin use and covariates were updated every 2 years and strokes were documented by review of medical records. Hazard ratios of total, ischaemic and hemorrhagic strokes were calculated across categories of multivitamin use (non-user, past, current user) and duration (years), using Cox proportional hazards models.

RESULTS

During 32 years of follow-up from 1980 to 2012, 3615 incident strokes were documented, including 758 deaths from stroke. In multivariate analyses, women who were current multivitamin users did not have a lower risk of incident total stroke compared to non-users [relative risk (RR) 1.02, 95% confidence interval (CI) 0.93-1.11], even those with longer durations of 15 or more years of use (RR 1.08, 95% CI 0.97-1.20) or those with a lower quality diet (RR 0.96, 95% CI 0.80-1.15). There was also no indication of benefit from multivitamin use for incident ischaemic or hemorrhagic strokes or for total stroke mortality.

CONCLUSIONS

Long-term multivitamin use was not associated with reduced risk of stroke incidence or mortality amongst women in the study population, even amongst those with a lower diet quality. An effect in a less well-nourished population cannot be ruled out.

Dietary patterns and all-cause, cancer, and cardiovascular disease mortality in Japanese men and women: The Japan public health center-based prospective study

OBJECTIVE

A meta-analysis showed an inverse association of a prudent/healthy dietary pattern with all-cause mortality and no association of a western/unhealthy dietary pattern. However, the association of distinctive dietary patterns of Japanese population with mortality remains unclear. We prospectively investigated the association between dietary patterns and all-cause, cancer, and cardiovascular disease mortality among Japanese adults.

METHODS

Participants were 36,737 men and 44,983 women aged 45-74 years who participated in the second survey of the Japan Public Health Center-based Prospective Study (1995-1998) and who had no history of serious disease. Dietary patterns were derived from principal component analysis of the consumption of 134 food and beverage items ascertained by a food frequency questionnaire. Hazard ratios of death from the second survey to December 2012 were estimated using cox proportional hazard regression analysis.

RESULTS

A prudent dietary pattern, which was characterized by high intake of vegetables, fruit, soy products, potatoes, seaweed, mushrooms, and fish, was significantly associated with decreased risk of all-cause and cardiovascular disease mortality. The multivariable-adjusted hazard ratios (95% confidence intervals) of all-cause and cardiovascular disease mortality for the highest versus lowest quartile of the prudent dietary pattern score were 0.82 (0.77 to 0.86) and 0.72 (0.64 to 0.79), respectively (P for trend <0.001 in both). A Westernized dietary pattern, characterized by high intake of meat, processed meat, bread, and dairy products, was also inversely associated with risk of all-cause, cancer, and cardiovascular disease mortality. A traditional Japanese dietary pattern was not associated with these risks.

CONCLUSIONS

The prudent and Westernized dietary patterns were associated with a decreased risk of all-cause and cardiovascular disease mortality in Japanese adults.

Estimation of dietary total antioxidant capacity of Korean adults

PURPOSE

Dietary total antioxidant capacity (TAC) has been reported to be inversely associated with the risk of chronic diseases. However, little is known about dietary TAC among the Korean population. Therefore, we aimed to estimate the dietary TAC of Korean adults and to document the major food sources.

METHODS

We studied 33,581 Korean adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey 2007-2012. Dietary TAC was estimated from 1-day 24-h dietary recall data using a TAC database comprising antioxidant capacities of 42 dietary antioxidants, developed for common Korean foods.

RESULTS

The average dietary TAC of Korean adults was 384.7 mg VCE/d, and the major contributors were flavonoids, followed by vitamin C and E. The energy-adjusted daily TAC level was higher in women, middle-aged adults, non-regular alcohol consumers, current non-smokers, supplement users, and in those with a higher income and education level than in their counterparts (P < 0.001). Fruits (47.3%), vegetables (28.4%), beverages and alcohols (11.2%), and legumes and legume products (5.5%), in particular, grapes, persimmons, mandarins, apples, and green tea, were major food sources of dietary TAC. In addition, the consumption of nutrient-dense foods, such as fruits and vegetables, increased, whereas the intake of energy and fat decreased across quartiles of energy-adjusted dietary TAC.

CONCLUSIONS

The present study documented the baseline dietary TAC of Korean adults and the major food sources thereof using nationally representative data. Further research on the health effects of dietary TAC among Korean adults is warranted.

The role of nutraceuticals for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease. It is characterized by a wide spectrum of hepatic changes, which may progress to liver fibrosis and to cirrhosis. NAFLD is considered as the hepatic component of the metabolic syndrome but mechanisms underlying the onset and progression of NAFLD are still under investigation. The traditional 'two hit hypothesis' has been developed within a more complex 'multiple parallel hit hypothesis' which comprises a wide spectrum of parallel hits. Many therapeutic approaches have been proposed so far and several types of nutraceuticals have been suggested for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH), the most promising of which are those with antioxidant effects. In particular, vitamin E appears to be effective for the treatment of nondiabetic subjects with more advanced NASH, although the high suggested daily dosages are a matter of concern. Moreover, polyphenols reduce liver fat accumulation, mainly by inhibiting lipogenesis. At present, there are insufficient data to support the use of vitamin C supplements in patients with NAFLD. Data on polyunsaturated fatty acid (PUFA) supplementation are heterogeneous, and no well-designed randomized controlled studies (RCTs) of adequate size, with histological assessment of steatosis, have been conducted. Based on the available data, silymarin supplementation for the treatment of NAFLD seems to have a favourable effect. The results with anti-inflammatory agents, such as vitamin D and carnitine are uncertain. In conclusion, there are insufficient data either to support or refute the use of nutraceuticals for subjects with NAFLD. Further RTCs, with histological changes as an outcome measure, are needed.