Serum β-carotene and the risk of sudden cardiac death in men: a population-based follow-up study

Innovative Bioactive Products with Medicinal Value from Microalgae and Their Overall Process Optimization through the Implementation of Life Cycle Analysis-An Overview

Microalgae are being recognized as valuable sources of bioactive chemicals with important medical properties, attracting interest from multiple industries, such as food, feed, cosmetics, and medicines. This review study explores the extensive research on identifying important bioactive chemicals from microalgae, and choosing the best strains for nutraceutical manufacturing. It explores the most recent developments in recovery and formulation strategies for creating stable, high-purity, and quality end products for various industrial uses. This paper stresses the significance of using Life Cycle Analysis (LCA) as a strategic tool with which to improve the entire process. By incorporating LCA into decision-making processes, researchers and industry stakeholders can assess the environmental impact, cost-effectiveness, and sustainability of raw materials of several approaches. This comprehensive strategy will allow for the choosing of the most effective techniques, which in turn will promote sustainable practices for developing microalgae-based products. This review offers a detailed analysis of the bioactive compounds, strain selection methods, advanced processing techniques, and the incorporation of LCA. It will serve as a valuable resource for researchers and industry experts interested in utilizing microalgae for producing bioactive products with medicinal properties.

Waterpipe Use and Its Cardiovascular Effects: A Systematic Review and Meta-Analysis of Case-Control, Cross-Sectional, and Non-Randomized Studies

Approximately 100 million people globally smoke cigarettes, making it a significant and quickly spreading global tobacco epidemic. Substance use disorders are frequently evaluated by non-randomized studies. Tobacco use and its impacts on the cardiovascular system were the subjects of a comprehensive search across five electronic databases: Cochrane, MEDLINE, Scopus, Embase, and PubMed. The findings demonstrated that waterpipe smokers in comparison to non-smokers have immediate elevations in heart rate and blood pressure, lower levels of high-density lipoprotein, higher levels of low-density lipoprotein, higher levels of triglycerides, higher levels of fasting blood glucose, and a higher heart rate. Users of waterpipes and cigarettes had similar average heart rates, blood pressure, and lipid levels, with the exception that waterpipe smokers had greater total cholesterol. Smoking a waterpipe has significant negative effects on the cardiovascular system comparable to cigarette smoking, and non-randomized studies proved to yield substantial evidence related to its cardiovascular effects. Such study designs can be used to evaluate substance use and its cardiovascular impact.

Asterarcys quadricellulare (Chlorophyceae) protects H9c2 cardiomyoblasts from H2O2-induced oxidative stress

Oxidative stress has recently been identified as an important mediator of cardiovascular diseases. The need to find efficient antioxidant molecules is essential in the disease's prevention. Therefore, the present study aimed to evaluate the potential of microalgae bioactive in protecting H9c2 cardiomyoblasts from H₂O₂-induced oxidative stress. Four microalgal species were investigated for their antioxidant capacity. A qualitative assessment of oxidative stress in H9c2 cardiomyoblasts stained with DCFH-DA, treated with the highly active microalgae extracts, was performed. The protein expression of total caspase-3 was also examined to investigate whether the extract protects H9c2 cardimyoblasts from H₂O₂-induced apoptosis. High antioxidant activity was observed for the hexanoic extracts after 10 days of cultivation. Asterarcys quadricellulare exhibited the highest antioxidant capacity of 110.59 ± 1.75 mg TE g^-1 dry weight and was tested against H9c2 cardiomyoblasts, which were initially subjected to H₂O₂-induced oxidative stress. This hexanoic extract protected against H₂O₂ induced oxidative stress with a similar scavenging capacity as N-Acetylcysteine. Furthermore, total caspase-3 was increased following treatment with the hexanoic extract, suggesting that A. quadricellulare also had anti-apoptotic properties. The outcome of our study highlighted the possible use of the local A. quadricellulare strain QUCCCM10 as a natural, safe, and efficient antioxidant to prevent cardiovascular diseases.

Improving the Bioaccessibility and Bioavailability of Carotenoids by Means of Nanostructured Delivery Systems: A Comprehensive Review

Carotenoids are bioactive compounds provided by the diet playing a key role in maintaining human health. Therefore, they should be ingested daily in an adequate amount. However, even a varied and well-balanced diet does not guarantee an adequate intake, as both the bioaccessibility and bioavailability of the compounds significantly affect their absorption. This review summarizes the main results achieved in improving the bioaccessibility and bioavailability of carotenoids by means of nanostructured delivery systems, discussing in detail the available lipid-based and biopolymeric nanocarriers at present, with a focus on their formulation and functional efficiency. Although the toxicity profile of these innovative delivery systems is not fully understood, especially for long-term intake, these systems are an effective and valuable approach to increase the availability of compounds of nutritional interest.

Diet and Sudden Death: How to Reduce the Risk

In addition to the association of dietary patterns, specific foods and nutrients with several diseases, including cardiovascular disease and mortality, there is also strong emerging evidence of an association of dietary patterns with the risk of sudden cardiac death (SCD). In this comprehensive review, data are presented and analyzed about foods and diets that mitigate the risk of ventricular arrhythmias (VAs) and SCD, but also about arrhythmogenic nutritional elements and patterns that seem to enhance or facilitate potentially malignant VAs and SCD. The antiarrhythmic or protective group comprises fish, nuts and other foods enriched in omega-3 polyunsaturated fatty acids, the Mediterranean and other healthy diets, vitamins E, A and D and certain minerals (magnesium, potassium, selenium). The arrhythmogenic-food group includes saturated fat, trans fats, ketogenic and liquid protein diets, the Southern and other unhealthy diets, energy drinks and excessive caffeine intake, as well as heavy alcohol drinking. Relevant antiarrhythmic mechanisms include modification of cell membrane structure by n-3 polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their important role in eicosanoid metabolism, enhancing myocyte electric stability, reducing vulnerability to VAs, lowering heart rate, and improving heart rate variability, each of which is a risk factor for SCD. Contrarily, saturated fat causes calcium handling abnormalities and calcium overload in cardiomyocytes, while a high-fat diet causes mitochondrial dysfunction that dysregulates a variety of ion channels promoting VAs and SCD. Free fatty acids have been considered proarrhythmic and implicated in facilitating SCD; thus, diets increasing free fatty acids, e.g., ketogenic diets, should be discouraged and replaced with diets enriched with polyunsaturated fatty acids, which can also reduce free fatty acids. All available relevant data on this important topic are herein reviewed, large studies and meta-analyses and pertinent advisories are tabulated, while protective (antiarrhythmic) and arrhythmogenic specific diet constituents are pictorially illustrated.

Retinoic acid regulates pyruvate dehydrogenase kinase 4 (Pdk4) to modulate fuel utilization in the adult heart: Insights from wild-type and β-carotene 9',10' oxygenase knockout mice

Regulation of the pyruvate dehydrogenase (PDH) complex by the pyruvate dehydrogenase kinase PDK4 enables the heart to respond to fluctuations in energy demands and substrate availability. Retinoic acid, the transcriptionally active form of vitamin A, is known to be involved in the regulation of cardiac function and growth during embryogenesis as well as under pathological conditions. Whether retinoic acid also maintains cardiac health under physiological conditions is unknown. However, vitamin A status and intake of its carotenoid precursor β-carotene have been linked to the prevention of heart diseases. Here, we provide in vitro and in vivo evidence that retinoic acid regulates cardiac Pdk4 expression and thus PDH activity. Furthermore, we show that mice lacking β-carotene 9',10'-oxygenase (BCO2), the only enzyme of the adult heart that cleaves β-carotene to generate retinoids (vitamin A and its derivatives), displayed cardiac retinoic acid insufficiency and impaired metabolic flexibility linked to a compromised PDK4/PDH pathway. These findings provide novel insights into the functions of retinoic acid in regulating energy metabolism in adult tissues, especially the heart.

Predictive role of C-reactive protein in sudden death: a meta-analysis of prospective studies

Objective

C-reactive protein (CRP) is a powerful predictor of and risk factor for cardiovascular disease. However, the relationship between CRP and sudden death (SD) is controversial. Therefore, we performed a meta-analysis to evaluate the association between CRP and SD.

Methods

We conducted a comprehensive search of the databases of PubMed, Web of Science, Embase, Cochrane Library, Wanfang, CNKI, China Biology Medicine disc, and Weipu. Two researchers independently screened the literature, extracted data, and evaluated the data quality. The overall effect size was meta-analyzed using Stata software version 12.0 (StataCorp, College Station, TX, USA).

Results

Twelve prospective studies involving 36,646 patients were included in the present meta-analysis. The data revealed that patients with higher CRP concentrations had a greater risk of SD (hazard ratio, 1.19; 95% confidence interval, 1.09–1.29). When the hazard ratio of SD was calculated by multivariate analysis of nine studies, CRP was confirmed to be an independent predictive factor for SD (hazard ratio, 1.05; 95% confidence interval, 1.03–1.07).

Conclusions

This meta-analysis confirmed that CRP is an independent predictor of SD. These results support the recommendation of recording the CRP concentration for risk assessment of SD in clinical practice.

The Impact of Obesity on Sudden Cardiac Death Risk

PURPOSE OF REVIEW

We aimed to describe the epidemiology of sudden cardiac death (SCD) in the obese, elaborating on the potential pathophysiological mechanisms linking obesity, SCD, and the outcomes in SCD survivors, as well as looking into the intriguing "obesity paradox" in these patients.

RECENT FINDINGS

Several studies show increased mortality in patients with BMI > 30 kg/m² admitted to the hospital following SCD. At the same time, other studies have implied that the "obesity paradox," described in various cardiovascular conditions, applies to patients admitted after SCD, showing lower mortality in the obese compared to normal weight and underweight patients. We found a significant body of evidence to support that while obesity increases the risk for SCD, the outcomes of obese patients post SCD are better. These findings should not be interpreted as supporting weight gain, as it is always better to prevent the "disaster" from happening than to improve your chances of surviving it. Obesity is shown to be significantly associated with increased risk for SCD; however, there is a growing body of evidence, supporting the "obesity paradox" in the survival of SCD victims. Prospectively, well-designed studies are needed to confirm these findings.

Ageing, Age-Related Cardiovascular Risk and the Beneficial Role of Natural Components Intake

Ageing, in a natural way, leads to the gradual worsening of the functional capacity of all systems and, eventually, to death. This process is strongly associated with higher metabolic and oxidative stress, low-grade inflammation, accumulation of DNA mutations and increased levels of related damage. Detrimental changes that accumulate in body cells and tissues with time raise the vulnerability to environmental challenges and enhance the risk of major chronic diseases and mortality. There are several theses concerning the mechanisms of ageing: genetic, free radical telomerase, mitochondrial decline, metabolic damage, cellular senescence, neuroendocrine theory, Hay-flick limit and membrane theories, cellular death as well as the accumulation of toxic and non-toxic garbage. Moreover, ageing is associated with structural changes within the myocardium, cardiac conduction system, the endocardium as well as the vasculature. With time, the cardiac structures lose elasticity, and fibrotic changes occur in the heart valves. Ageing is also associated with a higher risk of atherosclerosis. The results of studies suggest that some natural compounds may slow down this process and protect against age-related diseases. Animal studies imply that some of them may prolong the lifespan; however, this trend is not so obvious in humans.

Short-Term Effects of Supplemental L-Arginine, Diosmin, Troxerutin, and Hesperidin in Diabetic Patients: A Pilot Study

Background and Aims

Inflammatory, oxidative stress, and endothelial dysfunction play a key role in the pathogenesis of long-term cardiovascular complications in patients with diabetes. The present observational prospective study is aimed at evaluating the effects of micronutrients and phytochemicals contained in the dietary supplement Flebotrofine® (AMNOL Chimica Biologica) on biochemical markers of inflammation, endothelial dysfunction, and glycemic control in patients with diabetes.

Methods

105 type 1 or type 2 diabetes patients regularly took a daily dose of the dietary supplement Flebotrofine® for three consecutive months, and haematological and biochemical parameters were checked at baseline, after three months of treatment, and one month after its suspension. Statistical comparison of the laboratory parameters was performed using the two-tailed ANOVA test for repeated samples with a statistical significance level set at p < 0.05.

Results

The daily use of Flebotrofine® did not change the glycemic metabolic compensation of enrolled patients. After three months of regular Flebotrofine® intake, the plasma levels of the antioxidant β-carotene and of arginine were significantly higher compared with the baseline values, with a decrease in the ADMA/arginine ratio. In contrast, apolipoprotein B, ApoB/ApoA1 ratio, and platelet and leukocyte counts significantly dropped.

Conclusion

The daily use of Flebotrofine® might be a valid supplement of arginine, the precursor of NO, and essential in the prevention of endothelial dysfunction. The regular intake of arginine and phytochemicals also improved the antioxidant and antithrombotic profile of enrolled patients. Therefore, Flebotrofine® could be a useful dietary supplement to prevent long-term complications in patients with diabetes.

Anthropometric indices and the risk of incident sudden cardiac death among adults with and without diabetes: over 15 years of follow-up in The Tehran Lipid and Glucose Study

BACKGROUND

We investigated the association of anthropometric indices including body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and hip circumference (HC) with the risk of incident sudden cardiac death (SCD) among Iranian population with and without type 2 diabetes mellitus (T2DM).

METHODS

The study population included 9,089 subjects without and 1,185 subjects with T2DM, aged ≥ 20 years. Participants were recruited in 1999-2001 or 2001-2005, and followed for incident SCD annually, up to 20 March 2018. Multivariate Cox proportional hazard models, adjusted for traditional risk factors of cardiovascular disease, were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of anthropometric indices (as continuous and categorical variables).

RESULTS

During a follow-up of over 15 years, 144 (1.58%) and 86 (7.26%) incident SCD occurred in non-T2DM and T2DM groups, respectively. Among non-T2DM group, a 1 standard deviation (SD) increase in WHtR was associated with higher risk of incident SCD by a HR of 1.23 (95% CI: 1.00-1.50) in the multivariable model. From the first quartile to the fourth quartile of WHtR, the trend of SCD risk was significant in age- and sex-adjusted analysis (P-value for trend: 0.041). Other indices did not show significant associations with SCD. Among T2DM group, a 1 SD increase in WHR had a HR of 1.36 (1.05-1.76) in the multivariable model. Considering WHR as categorical variables, the trend of SCD risk across quartiles of WHR was significant. Furthermore, a 1 SD increase in HC led to reduced risk of incident SCD with a HR of 0.75 (0.58-0.97) in multivariable analysis; this lower risk remained significant even after adjustment for WC. Compared to the first quartile, the fourth quartile of HC also showed a HR of 0.50 (0.25-0.99) (P-value for trend = 0.018). BMI, WC, and WHtR did not have significant associations with incident SCD.

CONCLUSION

In our long-term population-based study, we demonstrated central but not general obesity (as assessed by WHR in participants with T2DM, and WHtR in participants without T2DM) as a herald of incident SCD. Moreover, HC can have an inverse association with SCD among participants with T2DM.

Association Between Dietary Inflammatory Index and Heart Failure: Results From NHANES (1999-2018)

Objective: To explore the relationship between dietary inflammatory index (DII) and heart failure (HF) in participants with cardiovascular and cerebrovascular diseases.

Methods: NHANES (1998–2018) data were collected and used to assess the association of HF with DII. Twenty-four-hour dietary consumptions were used to calculate the scores of DII. Demographic characteristics and physical and laboratory examinations were collected for the comparison between HF and non-HF groups. Logistic regression analysis and random forest analysis were performed to calculate the odds rate and determine the potential beneficial dietary components in HF.

Results: A total of 19,067 cardiac-cerebral vascular disease participants were categorized as HF (n = 1,382; 7.25%) and non-HF (n = 17,685; 92.75%) groups. Heart failure participants had higher levels of DII score compared with those in the non-HF group (0.239 ± 1.702 vs. −0.145 ± 1.704, p < 0.001). Compared with individuals with T1 (DII: −3.884 to −0.570) of DII, those in T3 (DII: 1.019 to 4.598) had a higher level of total cholesterol (4.49 ± 1.16 vs. 4.75 ± 1.28 mmol/L, p < 0.01), globulin (29.92 ± 5.37 vs. 31.29 ± 5.84 g/L, p < 0.001), and pulse rate (69.90 ± 12.22 vs. 72.22 ± 12.77, p < 0.001) and lower levels of albumin (40.76 ± 3.52 vs. 39.86 ± 3.83 g/L, p < 0.001), hemoglobin (13.76 ± 1.65 vs. 13.46 ± 1.77 g/dl, p < 0.05), and hematocrit (40.83 ± 4.69 vs. 40.17 ± 5.01%, p < 0.05). The odds rates of HF for DII from the logistic regression were 1.140, 1.158, and 1.110 in models 1, 2, and 3, respectively. In addition, from the results of random forest analysis, dietary magnesium, fiber, and beta carotene may be essential in HF.

Conclusion: Dietary inflammatory index was positively associated with HF in US adults, and dietary intervention might be a promising method in the therapy of HF.

A new approach to study human perivascular adipose tissue of the internal mammary artery by fiber-optic Raman spectroscopy supported by spectral modelling

Perivascular adipose tissue (PVAT) regulates vascular function and represents a novel therapeutic target in vascular diseases. In this work, a new approach based on fiber-optic Raman spectroscopy and spectral modelling was used to characterize the chemical content of the PVAT of the internal mammary artery (IMA) of patients with advanced coronary atherosclerosis (n = 10) undergoing coronary bypass surgery. Our results showed a high degree of lipid unsaturation and low carotenoid content in the PVAT of the IMA of patients with more advanced coronary artery disease. Moreover, the spectral modelling of the IMA's PVAT composition indicated that glyceryl trioleate was a major PVAT lipid and for patients with relatively low levels of β-carotene, it was accompanied by arachidonic acid and glyceryl trilinolenate. In summary, our proof-of-concept study suggests that carotenoid content and lipid unsaturation degree may reflect the PVAT functional status and a Raman-based assessment of the PVAT of the IMA could prove useful as a novel diagnostic tool to rapidly define the PVAT phenotype in a grafted artery in patients undergoing coronary bypass.

Physical activity and the risk of sudden cardiac death: a systematic review and meta-analysis of prospective studies

Background

Physical activity has been associated with a significant reduction in risk of sudden cardiac death in epidemiological studies, however, the strength of the association needs clarification. We conducted a systematic review and meta-analysis to summarize the available data from population-based prospective studies.

Methods

PubMed and Embase databases were searched for studies of physical activity and sudden cardiac death from inception to March 26th 2019. Prospective studies reporting adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) of sudden cardiac death associated with physical activity were included. A random effects model was used to estimate summary RRs (95% CIs).

Results

Thirteen prospective studies were included in the systematic review. Eight prospective studies with 1193 sudden cardiac deaths among 136,298 participants were included in the meta-analysis of physical activity and sudden cardiac death and the summary RR for highest vs. lowest level of physical activity was 0.52 (95% CI: 0.45–0.60, I² = 0%, p_{heterogeneity} = 0.72). The association was similar in men and women and among American and European studies. In the dose-response analysis the summary RR was 0.68 (95% CI: 0.55–0.86, I² = 44%, n = 3) per 20 MET-hours/week. Although the test for nonlinearity was not significant, p_nonlinearity = 0.18, there was no further reduction in risk beyond 20–25 MET-hours/week. The summary RR was 0.58 (95% CI: 0.41–0.81, I² = 0%, p_{heterogeneity} = 0.65, n = 2) for the highest vs. the lowest level of cardiorespiratory fitness.

Conclusion

This meta-analysis suggest that a high compared to a low level of physical activity may reduce the risk of sudden cardiac death in the general population. Further studies are needed to clarify the dose-response relationship between specific subtypes and intensities of physical activity in relation to sudden cardiac death.

Blood pressure, hypertension and the risk of sudden cardiac death: a systematic review and meta-analysis of cohort studies

Cardiovascular disease is the leading cause of death worldwide, while sudden cardiac death (SCD) accounts for over 60% of all cardiovascular deaths. Elevated blood pressure and hypertension have been associated with increased risk of SCD, but the findings have not been consistent. To clarify whether blood pressure or hypertension is associated with increased risk of SCD and to quantify the size and the shape of any association observed. PubMed and Embase databases were searched for published prospective studies on blood pressure or hypertension and SCD up to 30 April 2018. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random effects model. The meta-analysis included 2939 SCDs among 418,235 participants from 18 studies. The summary RRs were 2.10 (95% CI 1.71-2.58, I² = 56.7%, p_{heterogeneity} = 0.018, n = 10) for prevalent hypertension, 1.28 (95% CI 1.19-1.38, I² = 45.5%, p_{heterogeneity} = 0.07, n = 10) per 20 mmHg increment in systolic blood pressure (SBP) and 1.09 (95% CI 0.83-1.44, I² = 83.4%, p_{heterogeneity} = 0.002, n = 3) per 10 mmHg increment in diastolic blood pressure (DBP). A nonlinear relationship was suggested between SBP and SCD. The results persisted in most subgroup and sensitivity analyses. There was no evidence of publication bias. This meta-analysis found an increased risk of SCD with hypertension diagnosis and increasing SBP. Future studies should clarify the association for DBP and the shape of the dose-response relationship between blood pressure and SCD.

Toward a panoramic perspective of the association between environmental factors and cardiovascular disease: An environment-wide association study from National Health and Nutrition Examination Survey 1999-2014

OBJECTIVES

An environment-wide association study (EWAS) may be useful to comprehensively test and validate associations between environmental factors and cardiovascular disease (CVD) in an unbiased manner.

APPROACH AND RESULTS

Data from National Health and Nutrition Examination Survey (1999-2014) were randomly 50:50 spilt into training set and testing set. CVD was ascertained by a self-reported diagnosis of myocardial infarction, coronary heart disease or stroke. We performed multiple linear regression analyses associating 203 environmental factors and 132 clinical phenotypes with CVD in training set (false discovery rate < 5%) and significant factors were validated in the testing set (P < 0.05). Random forest (RF) model was used for multicollinearity elimination and variable importance ranking. Discriminative power of factors for CVD was calculated by area under the receiver operating characteristic (AUROC). Overall, 43,568 participants with 4084 (9.4%) CVD were included. After adjusting for age, sex, race, body mass index, blood pressure and socio-economic level, we identified 5 environmental variables and 19 clinical phenotypes associated with CVD in training and testing dataset. Top five factors in RF importance ranking were: waist, glucose, uric acid, and red cell distribution width and glycated hemoglobin. AUROC of the RF model was 0.816 (top 5 factors) and 0.819 (full model). Sensitivity analyses reveal no specific moderators of the associations.

CONCLUSION

Our systematic evaluation provides new knowledge on the complex array of environmental correlates of CVD. These identified correlates may serve as a complementary approach to CVD risk assessment. Our findings need to be probed in further observational and interventional studies.

Body mass index, abdominal fatness, and the risk of sudden cardiac death: a systematic review and dose-response meta-analysis of prospective studies

Although overweight and obesity are established risk factors for some types of heart disease including ischemic heart disease, heart failure and atrial fibrillation, less is known about the association between adiposity and sudden cardiac death. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of sudden cardiac death. PubMed and Embase databases were searched up to July 20th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. The summary RR was 1.16 (95% CI 1.05-1.28, I2 = 68%, n = 14) per 5 unit increment in BMI, and 1.82 (95% CI 1.61-2.07, I2 = 0%, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.03 (95% CI 0.93-1.15, I2 = 0%, n = 2) per 10 cm increase in waist circumference. The heterogeneity in the analysis of BMI and sudden cardiac death persisted across most subgroup analyses. The association was stronger among studies with longer follow-up compared to short follow-up and was observed in the European and American studies, but not in the Asian studies. There was a J-shaped association between BMI and sudden cardiac death and the lowest risk was observed in the normal weight range, however, the increased risk with a low BMI was attenuated among studies with a longer duration of follow-up. This meta-analysis suggest an increased risk of sudden cardiac death with increasing BMI and waist-to-hip ratio, however, further studies with stratification for smoking status are needed of waist circumference, weight changes and adiposity at younger ages.

Intrinsic and Extrinsic Factors Impacting Absorption, Metabolism, and Health Effects of Dietary Carotenoids

Carotenoids are orange, yellow, and red lipophilic pigments present in many fruit and vegetables, as well as other food groups. Some carotenoids contribute to vitamin A requirements. The consumption and blood concentrations of specific carotenoids have been associated with reduced risks of a number of chronic conditions. However, the interpretation of large, population-based observational and prospective clinical trials is often complicated by the many extrinsic and intrinsic factors that affect the physiologic response to carotenoids. Extrinsic factors affecting carotenoid bioavailability include food-based factors, such as co-consumed lipid, food processing, and molecular structure, as well as environmental factors, such as interactions with prescription drugs, smoking, or alcohol consumption. Intrinsic, physiologic factors associated with blood and tissue carotenoid concentrations include age, body composition, hormonal fluctuations, and variation in genes associated with carotenoid absorption and metabolism. To most effectively investigate carotenoid bioactivity and to utilize blood or tissue carotenoid concentrations as biomarkers of intake, investigators should either experimentally or statistically control for confounding variables affecting the bioavailability, tissue distribution, and metabolism of carotene and xanthophyll species. Although much remains to be investigated, recent advances have highlighted that lipid co-consumption, baseline vitamin A status, smoking, body mass and body fat distribution, and genetics are relevant covariates for interpreting blood serum or plasma carotenoid responses. These and other intrinsic and extrinsic factors are discussed, highlighting remaining gaps in knowledge and opportunities for future research. To provide context, we review the state of knowledge with regard to the prominent health effects of carotenoids.

Tobacco smoking and the risk of sudden cardiac death: a systematic review and meta-analysis of prospective studies

Smoking is an established risk factor for cardiovascular disease including coronary heart disease and stroke, however, data regarding smoking and sudden cardiac death have not been summarized in a meta-analysis previously. We therefore conducted a systematic review and meta-analysis to clarify this association. We searched the PubMed and Embase databases for studies of smoking and sudden cardiac death up to July 20th 2017. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for smoking and sudden cardiac death. Summary RRs were estimated by use of a random effects model. Twelve prospective studies were included. The summary RR was 3.06 (95% CI 2.46–3.82, I² = 41%, p_{heterogeneity} = 0.12, n = 7) for current smokers and 1.38 (95% CI 1.20–1.60, I² = 0%, p_{heterogeneity} = 0.55, n = 7) for former smokers compared to never smokers. For four studies using non-current (never + former) smokers as the reference category the summary RR among current smokers was 2.08 (95% CI 1.70–2.53, I² = 18%, p_{heterogeneity} = 0.30). The results persisted in most of the subgroup analyses. There was no evidence of publication bias. These results confirm that smoking increases the risk of sudden cardiac death. Any further studies should investigate in more detail the effects of duration of smoking, number of cigarettes per day, pack-years, and time since quitting smoking and sudden cardiac death.

Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies

Observational studies evaluating the relation between dietary or circulating level of beta-carotene and risk of total mortality yielded inconsistent results. We conducted a comprehensive search on publications of PubMed and EMBASE up to 31 March 2016. Random effect models were used to combine the results. Potential publication bias was assessed using Egger’s and Begg’s test. Seven studies that evaluated dietary beta-carotene intake in relation to overall mortality, indicated that a higher intake of beta-carotene was related to a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.83, 95%CI: 0.78–0.88) with no evidence of heterogeneity between studies (I² = 1.0%, P = 0.416). A random-effect analysis comprising seven studies showed high beta-carotene level in serum or plasma was associated with a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.69, 95%CI: 0.59–0.80) with low heterogeneity (I² = 37.1%, P = 0.145). No evidence of publication bias was detected by Begg’s and Egger’s regression tests. In conclusion, dietary or circulating beta-carotene was inversely associated with risk of all-cause mortality. More studies should be conducted to clarify the dose-response relationship between beta-carotene and all-cause mortality.

Biosynthesis of Carotenoids in Plants: Enzymes and Color

Carotenoids are the most important biocolor isoprenoids responsible for yellow, orange and red colors found in nature. In plants, they are synthesized in plastids of photosynthetic and sink organs and are essential molecules for photosynthesis, photo-oxidative damage protection and phytohormone synthesis. Carotenoids also play important roles in human health and nutrition acting as vitamin A precursors and antioxidants. Biochemical and biophysical approaches in different plants models have provided significant advances in understanding the structural and functional roles of carotenoids in plants as well as the key points of regulation in their biosynthesis. To date, different plant models have been used to characterize the key genes and their regulation, which has increased the knowledge of the carotenoid metabolic pathway in plants. In this chapter a description of each step in the carotenoid synthesis pathway is presented and discussed.

Lycopene Protects against Hypoxia/Reoxygenation Injury by Alleviating ER Stress Induced Apoptosis in Neonatal Mouse Cardiomyocytes

Endoplasmic reticulum (ER) stress induced apoptosis plays a pivotal role in myocardial ischemia/reperfusion (I/R)-injury. Inhibiting ER stress is a major therapeutic target/strategy in treating cardiovascular diseases. Our previous studies revealed that lycopene exhibits great pharmacological potential in protecting against the I/R-injury in vitro and vivo, but whether attenuation of ER stress (and) or ER stress-induced apoptosis contributes to the effects remains unclear. In the present study, using neonatal mouse cardiomyocytes to establish an in vitro model of hypoxia/reoxygenation (H/R) to mimic myocardium I/R in vivo, we aimed to explore the hypothesis that lycopene could alleviate the ER stress and ER stress-induced apoptosis in H/R-injury. We observed that lycopene alleviated the H/R injury as revealed by improving cell viability and reducing apoptosis, suppressed reactive oxygen species (ROS) generation and improved the phosphorylated AMPK expression, attenuated ER stress as evidenced by decreasing the expression of GRP78, ATF6 mRNA, sXbp-1 mRNA, eIF2α mRNA and eIF2α phosphorylation, alleviated ER stress-induced apoptosis as manifested by reducing CHOP/GADD153 expression, the ratio of Bax/Bcl-2, caspase-12 and caspase-3 activity in H/R-treated cardiomyocytes. Thapsigargin (TG) is a potent ER stress inducer and used to elicit ER stress of cardiomyocytes. Our results showed that lycopene was able to prevent TG-induced ER stress as reflected by attenuating the protein expression of GRP78 and CHOP/GADD153 compared to TG group, significantly improve TG-caused a loss of cell viability and decrease apoptosis in TG-treated cardiomyocytes. These results suggest that the protective effects of lycopene on H/R-injury are, at least in part, through alleviating ER stress and ER stress-induced apoptosis in neonatal mouse cardiomyocytes.

The inhibition of macrophage foam cell formation by 9-cis β-carotene is driven by BCMO1 activity

Atherosclerosis is a major cause of morbidity and mortality in developed societies, and begins when activated endothelial cells recruit monocytes and T-cells from the bloodstream into the arterial wall. Macrophages that accumulate cholesterol and other fatty materials are transformed into foam cells. Several epidemiological studies have demonstrated that a diet rich in carotenoids is associated with a reduced risk of heart disease; while previous work in our laboratory has shown that the 9-cis β-carotene rich alga Dunaliella inhibits atherogenesis in mice. The effect of 9-cis β-carotene on macrophage foam cell formation has not yet been investigated. In the present work, we sought to study whether the 9-cis β-carotene isomer, isolated from the alga Dunaliella, can inhibit macrophage foam cell formation upon its conversion to retinoids. The 9-cis β-carotene and Dunaliella lipid extract inhibited foam cell formation in the RAW264.7 cell line, similar to 9-cis retinoic acid. Furthermore, dietary enrichment with the algal powder in mice resulted in carotenoid accumulation in the peritoneal macrophages and in the inhibition of foam cell formation ex-vivo and in-vivo. We also found that the β-carotene cleavage enzyme β-carotene 15,15’-monooxygenase (BCMO1) is expressed and active in macrophages. Finally, 9-cis β-carotene, as well as the Dunaliella extract, activated the nuclear receptor RXR in hepa1-6 cells. These results indicate that dietary carotenoids, such as 9-cis β-carotene, accumulate in macrophages and can be locally cleaved by endogenous BCMO1 to form 9-cis retinoic acid and other retinoids. Subsequently, these retinoids activate the nuclear receptor RXR that, along with additional nuclear receptors, can affect various metabolic pathways, including those involved in foam cell formation and atherosclerosis.

Green extraction methods and environmental applications of carotenoids-a review

This review covers and discusses various aspects of carotenoids including their chemistry, classification, biosynthesis, extraction methods (conventional and non-conventional), analytical techniques and biological roles in living beings.

Fruit and vegetable intake, as reflected by serum carotenoid concentrations, predicts reduced probability of polychlorinated biphenyl-associated risk for type 2 diabetes: National Health and Nutrition Examination Survey 2003-2004

Type 2 diabetes has been shown to occur in response to environmental and genetic influences, among them nutrition; food intake patterns; sedentary lifestyle; body mass index; and exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs). Nutrition is essential in the prevention and management of type 2 diabetes and has been shown to modulate the toxicity of PCBs. Serum carotenoid concentrations, considered a reliable biomarker of fruit and vegetable intake, are associated with the reduced probability of chronic diseases, such as type 2 diabetes and cardiovascular disease. Our hypothesis is that fruit and vegetable intake, reflected by serum carotenoid concentrations, is associated with the reduced probability of developing type 2 diabetes in US adults with elevated serum concentrations of PCBs 118, 126, and 153. This cross-sectional study used the Center for Disease Control and Prevention database, National Health and Nutrition Examination Survey 2003-2004, in logistic regression analyses. Overall prevalence of type 2 diabetes was approximately 11.6% depending on the specific PCB. All 3 PCBs were positively associated with the probability of type 2 diabetes. For participants at higher PCB percentiles (eg, 75th and 90th) for PCB 118 and 126, increasing serum carotenoid concentrations were associated with a smaller probability of type 2 diabetes. Fruit and vegetable intake, as reflected by serum carotenoid concentrations, predicted notably reduced probability of dioxin-like PCB-associated risk for type 2 diabetes.

Dietary intake of carotenoids and their antioxidant and anti-inflammatory effects in cardiovascular care

Cardiovascular disease related to atherosclerosis represents nowadays the largest cause of morbidity and mortality in developed countries. Due to inflammatory nature of atherosclerosis, several studies had been conducted in order to search for substances with anti-inflammatory activity on arterial walls, able to exert beneficial roles on health. Researches investigated the role of dietary carotenoids supplementation on cardiovascular disease, due to their free radicals scavenger properties and their skills in improving low-density lipoprotein cholesterol resistance to oxidation. Nevertheless, literature data are conflicting: although some studies found a positive relationship between carotenoids supplementation and cardiovascular risk reduction, others did not find any positive effects or even prooxidant actions. This paper aimed at defining the role of carotenoids supplementation on cardiovascular risk profile by reviewing literature data, paying attention to those carotenoids more present in our diet (β-carotene, α-carotene, β-cryptoxanthin, lycopene, lutein, zeaxanthin, and astaxanthin).

Carotenoids and chronic diseases

Chronic diseases such as cancer and cardiovascular diseases are the major causes of deaths in North America. Dietary intake of fruits and vegetables has been suggested to have protective effects against such chronic diseases. Carotenoids are important plant pigments which are thought to contribute towards the beneficial effects of fruit and vegetable consumption. This review focuses on the role of carotenoids and particularly lycopene in chronic diseases.