Vitamins and cardiovascular disease

Role of Vitamins in Cardiovascular Health: Know Your Facts - Part 1

Cardiovascular (CV) disease (CVD) is a major cause of morbidity and mortality world-wide, thus it is important to adopt preventive interventions. Observational data demonstrating CV benefits of vitamin supplements, advanced by self-proclaimed experts have resulted in ~50% of Americans reporting the use of multivitamins for health promotion; this practice has led to a multi-billion-dollar business of the multivitamin-industry. However, the data on the extensive use of multivitamins show no consistent benefit for CVD prevention or all-cause mortality, while the use of certain vitamins might prove harmful. Thus, the focus of this two-part review is on the attributes or concerns about specific vitamins on CVD. In Part 1, the CV effects of specific vitamins are discussed, indicating the need for further supportive evidence of potential benefits. Vitamin A preserves CV homeostasis as it participates in many biologic functions, including atherosclerosis. However, supplementation could potentially be harmful. Betacarotene, a pro-vitamin A, conveys pro-oxidant actions that may mitigate any other benefits. Folic acid alone and certain B-vitamins (e.g., B1/B2/B6/B12) may reduce CVD, heart failure, and/or stroke, while niacin might increase mortality. Vitamin C has antioxidant and cardioprotective effects. Vitamin D may confer CV protection, but all the data are not in agreement. Combined vitamin E and C have antiatherogenic effects but clinical evidence is inconsistent. Vitamin K seems neutral. Thus, there are individual vitamin actions with favorable CV impact (certain B-vitamins and vitamins C and D), but other vitamins (β-carotene, niacin) may potentially have deleterious effects, which also holds true for high doses of fat-soluble vitamins (A/D/E/K).

Role of Vitamins in Cardiovascular Health: Know Your Facts-Part 2

Cardiovascular disease (CVD) is a major cause of morbidity/mortality world-wide, hence preventive interventions are crucial. Observational data showing beneficial CV effects of vitamin supplements, promoted by self-proclaimed experts, have led to ~50% of Americans using multivitamins; this practice has culminated into a multi-billion-dollar business. However, robust evidence is lacking, and certain vitamins might incur harm. This two-part review focuses on the attributes or concerns about specific vitamin consumption on CVD. The evidence for indiscriminate use of multivitamins indicates no consistent CVD benefit. Specific vitamins and/or combinations are suggested, but further supportive evidence is needed. Data presented in Part 1 indicated that folic acid and certain B-vitamins may decrease stroke, whereas niacin might raise mortality; beta-carotene mediates pro-oxidant effects, which may abate the benefits from other vitamins. In Part 2, data favor the anti-oxidant effects of vitamin C and the anti-atherogenic effects of vitamins C and E, but clinical evidence is inconsistent. Vitamin D may provide CV protection, but data are conflicting. Vitamin K appears neutral. Thus, there are favorable CV effects of individual vitamins (C/D), but randomized/controlled data are lacking. An important caveat regards the potential toxicity of increased doses of fat-soluble vitamins (A/D/E/K). As emphasized in Part 1, vitamins might benefit subjects who are antioxidant-deficient or exposed to high levels of oxidative-stress (e.g., diabetics, smokers, and elderly), stressing the importance of targeting certain subgroups for optimal results. Finally, by promoting CV-healthy balanced-diets, we could acquire essential vitamins and nutrients and use supplements only for specific indications.

Phytotherapy of Hypertension: An Updated Overview

BACKGROUND

Cardiovascular disorders are the leading cause of morbidity and mortality throughout the globe. Hypertension is the main risk factor that contributes to the development of many diseases. The use of herbal therapies, medicinal plants and their derivatives for the remedy and management of hypertension is well-recognized and popular among a wide part of the world population.

METHODS

The aim of the current review was to collect, treat, and critically analyze the published research studies relative to experimental and clinical investigations which have studied the blood pressure lowering abilities of medicinal plant derivatives in the last decade. This review was organized into three principal axes; the first axis was attributed to the in vivo and in vitro experimental studies; the second treated the clinical trials; while, the last one is devoted to analyze the mechanisms of action underlying the therapeutic antihypertensive effectiveness of phytochemicals.

RESULTS

Different types of extracts and isolated molecules obtained from a large variety of species demonstrated their efficiency in improving the increase of blood pressure either experimentally or clinically. Medicinal species such as garlic (Allium sativum), celery (Apium graveolens), Black Cumin (Nigella sativa) and Ginseng (Panax) are among the most common and therapeutically used plant derivatives for controlling hypertension while Asteraceae, Apiaceae and Rosaceae are among the botanical families which were frequently studied in the last decade. Isolated compounds such as allicin and apigenin have received more interest in this field. Recent evidence from clinical trials suggests that a wide variety of herbal preparations and plant extracts or natural isolated compounds have a favorable therapeutic impact on blood flow. Interestingly, phytochemicals can either act directly on blood vessels via a vasorelaxant effect involving a variety of signaling cascades or indirectly through inhibiting or stimulating diversity of systems such as angiotensin-converting enzyme (ACE), renin-angiotensin system (RAS) or the diuretic activity. Hence, based on the findings of the present review medicinal plant derivatives could be used as preventive and curative agents in the case of cardiovascular disorders, particularly hypertension and could play a promoting function for the discovery of new antihypertensive agents.

CONCLUSION

The analysis of the published data shows that a great effort remains to be done to investigate the medicinal plants cited as antihypertensive through published ethnopharmacological surveys. The analysis of the literature in this field shows the lack of standardization at the level of experimental study methods as well as the need to study purified molecules. Moreover, the mechanistic studies when they exist remain in the whole partial. On the other hand, few advanced clinical studies have been conducted. Finally, the determination of the efficacy/safety ratio remains absent in almost all studies.

Cardiac retinoic acid levels decline in heart failure

Although low circulating levels of the vitamin A metabolite, all-trans retinoic acid (ATRA), are associated with increased risk of cardiovascular events and all-cause mortality, few studies have addressed whether cardiac retinoid levels are altered in the failing heart. Here, we showed that proteomic analyses of human and guinea pig heart failure (HF) were consistent with a decline in resident cardiac ATRA. Quantitation of the retinoids in ventricular myocardium by mass spectrometry revealed 32% and 39% ATRA decreases in guinea pig HF and in patients with idiopathic dilated cardiomyopathy (IDCM), respectively, despite ample reserves of cardiac vitamin A. ATRA (2 mg/kg/d) was sufficient to mitigate cardiac remodeling and prevent functional decline in guinea pig HF. Although cardiac ATRA declined in guinea pig HF and human IDCM, levels of certain retinoid metabolic enzymes diverged. Specifically, high expression of the ATRA-catabolizing enzyme, CYP26A1, in human IDCM could dampen prospects for an ATRA-based therapy. Pertinently, a pan-CYP26 inhibitor, talarozole, blunted the impact of phenylephrine on ATRA decline and hypertrophy in neonatal rat ventricular myocytes. Taken together, we submit that low cardiac ATRA attenuates the expression of critical ATRA-dependent gene programs in HF and that strategies to normalize ATRA metabolism, like CYP26 inhibition, may have therapeutic potential.

[Analysis of the biochemical, anthropometric profile, and of antioxidant micronutrient ingestion in patients with resistant arterial hypertension]

Introduction

Introduction: resistant arterial hypertension (HAR) is associated with a high risk for cardiovascular events due to oxidative stress. Research has shown the beneficial effects of dietary antioxidants on cardiovascular health. Objective: to analyze and correlate the biochemical, anthropometric profile and intake of antioxidant micronutrients of patients with HAR. Material and methods: the patients underwent a biochemical assessment, and an anthropometric assessment to calculate body mass index (IMC), waist circumference (PCI), hip circumference (PCA), waist-to-hip ratio (ICC), and micronutrient intake assessment: vitamin A, vitamin C, vitamin E, selenium and zinc, estimated by a semi-quantitative food frequency questionnaire and 24-hour recall. The statistical analysis was performed using the SPSS Statistics 20 software. A p-value < 0.05 was considered significant. Results: sixty individuals with HAR were studied, with a mean age of 62.83 ± 10.73 years. Mean IMC was 31.01 ± 5.60 kg/m², PCI, 98.12 ± 15.04 cm, PCA, 110.55 ± 13.16 cm, and ICC, 0.879 ± 0.084. Regarding the biochemical profile, mean total colesterol was 187.65 ± 48.29 mg/dL, triglycerides, 136.38 ± 99.91 mg/dL; HDL-col, 49.00 ± 10.99 mg/dL; LDL-col, 112.01 ± 41.89 mg/dL; glucose, 105.37 ± 14.81 mg/dL, and glycated hemoglobin, 6.29 ± 1.76 %. The average daily intake of antioxidants was: vitamin A, 241.47 ± 191.87 µg/d; vitamin C, 147.02 ± 192.94 mg/d; vitamin E, 1.99 ± 1.82 mg/d; selenium, 36.80 ± 34.56 µg/d, and zinc, 99.91 ± 6.64 mg/d, where 91.38 %, 46.55 %, 93.10 %, 67.24 %, and 46.55 % of the sample were below the recommended intakes, respectively. Conclusion: inadequate antioxidant intake was observed in these patients with HAR, with a high prevalence of obesity, especially visceral adiposity and alterations in lipid profile, conditions that require a greater usage of these micronutrients. We suggest there is a need for dietary planning for these patients to improve their quality of life and their response to antihypertensive treatment.

The Odyssey of Bioactive Compounds in Avocado (Persea americana) and Their Health Benefits

Persea americana, commonly known as avocado, has recently gained substantial popularity and is often marketed as a “superfood” because of its unique nutritional composition, antioxidant content, and biochemical profile. However, the term “superfood” can be vague and misleading, as it is often associated with unrealistic health claims. This review draws a comprehensive summary and assessment of research performed in the last few decades to understand the nutritional and therapeutic properties of avocado and its bioactive compounds. In particular, studies reporting the major metabolites of avocado, their antioxidant as well as bioavailability and pharmacokinetic properties, are summarized and assessed. Furthermore, the potential of avocado in novel drug discovery for the prevention and treatment of cancer, microbial, inflammatory, diabetes, and cardiovascular diseases is highlighted. This review also proposes several interesting future directions for avocado research.

The Impact of Natural Antioxidants on the Regenerative Potential of Vascular Cells

With advances in technology, the impact of natural antioxidants on vascular cell regeneration is attracting enormous attention as many current studies are now exploring the clinical potential of antioxidants in regenerative medicine. Natural antioxidants are an important step for improving future treatment and prevention of various diseases such as cardiovascular, cancer, neurodegenerative, and diabetes. The use of natural antioxidants which have effects on several types of stem cells with the potential to differentiate into functional endothelium and smooth muscle cells (known as vascular progenitors) for vascular regeneration might override pharmaceutical and surgical treatments. The natural antioxidant systems comprise of several components present in fruits, vegetables, legumes, medicinal plants, and other animal-derived products that interact with reactive free radicals such as oxygen and nitrogen species to neutralize their oxidative damaging effects on vascular cells. Neutralization by antioxidants involves the breaking down of the oxidative cascade chain reactions in the cell membranes in order to fine-tune the free radical levels. The effect of natural antioxidants on vascular regeneration includes restoration or establishment of new vascular structures and functions. In this review, we highlight the significant effects of natural antioxidants on modulating vascular cells to regenerate vessels, as well as possible mechanisms of action and the potential therapeutic benefits on health. The role of antioxidants in regenerating vessels may be critical for the future of regenerative medicine in terms of the maintenance of the normal functioning of vessels and the prevention of multiple vascular diseases.

Use of over the counter products in older cardiovascular patients admitted to a tertiary care center in USA

BACKGROUND

In recent years there has been a substantial increase in the use of over-the-counter (OTC) products around the world. While they are assumed to be safe by consumers, they can potentially lead to adverse effects and drug interactions particularly in older adults.

METHODS

We assessed the patterns of OTC products used by older adults admitted to the cardiology service in a tertiary care medical center in the USA over a three month period. We conducted a retrospective chart review where older adults with cardiovascular diseases (CVD) who were taking at least one OTC product at home were included.

RESULTS

Out of 404 patients who were admitted to the cardiology service, 281 (69.6%) were taking OTC products. Patients were taking a total of 659 OTC products; mean of 2.35 ± 1.57 and the range varied from 1 to 9 products. The most commonly used products were vitamins (37.3%), followed by laxatives (17%), minerals (13.6%), stomach acid reducers (9%), and analgesics (3.6%). OTC users were found to be suffering from more comorbidities and received more prescription medications as compared to non-users. Gender and age did not have an impact on the use of OTC products while patients with atrial fibrillation, sleep apnea and gastro-esophageal reflux disease were more likely to use OTC products.

CONCLUSION

Use of OTC products is quite frequent in older adults with CVD in our study. Clinicians should ask about OTC product usage and counsel patients about the risks and benefits associated with their use.

A Focus on Four Popular “Functional Foods” as Part of a Strategy to Combat Metabolic Disease Through the Increased Consumption of Fruits and Vegetables

Fruit and vegetable consumption is on the rise as an increasing number of people recognize their health promoting effects, which are mediated through phytochemicals with disease combatting properties. The aim of this paper is to identify the potential benefits of fruits and vegetables in chronic diseases such as diabetes mellitus and hypertension. An electronic search of databases such as Pubmed Central, Science Direct and Web of Science from the last 5 years was conducted. Four commonly consumed edible fruit and vegetables, namely, Hypoxis hemmerocallidea (African potato), Moringa oleifera (Moringa), Persea americana (Avocado) and Psidium guajava (Guava) and their potential role in the prevention and management of metabolic syndrome and other disorders, are presented. In this narrative review plant uses extend beyond traditional medicine and include usage in food preparation, beverages, as part of fragrances, culinary flavouring, as well as cosmetic use, but more importantly have potential in contributing to the amelioration of the deleterious effects of diseases/health conditions. In addressing disease states, including metabolic syndrome and other disorders, the interest in medicinal plants continues to grow with the possibility of novel compounds and/or new drug discovery. Alternative and affordable methods of large scale harvesting of medicinal plants, as well as identification and specificity of bioactive compounds as future therapeutics are essential for sustainability.

Serum Folate, Vitamin B-12, Vitamin A, γ-Tocopherol, α-Tocopherol, and Carotenoids Do Not Modify Associations between Cadmium Exposure and Leukocyte Telomere Length in the General US Adult Population

Background: Leukocyte telomere length (LTL) is a biomarker of the aging process and is associated with the risk of chronic disease. Higher exposure to cadmium may be associated with shorter LTL, and adequate nutrient concentrations may be associated with longer LTL; however, the potential interaction between metals and nutrients on LTL has yet to be examined.Objectives: The objective of this study was to evaluate whether serum concentrations of vitamins and carotenoids were associated with LTL, and whether they modified the association between blood cadmium and LTL in the US NHANES (1999-2002).Methods: We evaluated cross-sectional associations between LTL and serum concentrations of vitamin A, γ-tocopherol, α-tocopherol, folate, and vitamin B-12 (1999-2002; n = 7458) and α-carotene, β-carotene, β-cryptoxanthin, lutein + zeaxanthin, and lycopene (2001-2002; n = 4018) in a nationally representative sample of US adults (≥20 y of age) with the use of multivariable linear regression. We further investigated whether vitamin and carotenoid concentrations modified associations between blood cadmium and LTL with models stratified by serum nutrient concentrations and the inclusion of an interaction term.Results: Blood cadmium was inversely associated with LTL (percentage of LTL difference per 1 μg/L = -3.74; 95% CI: -5.35, -2.10). Serum vitamin A was positively associated (percentage of LTL difference per 1 μg/L = 4.01; 95% CI: 0.26, 7.90) and γ-tocopherol was inversely associated (percentage of LTL difference per 1 μg/dL = -2.49; 95% CI: -4.21, -0.73) with LTL. Serum folate (P-trend = 0.06) and α-tocopherol (P-trend = 0.10) were marginally positively associated with LTL, whereas vitamin B-12 (P-trend = 0.78) was not associated with LTL. Serum carotenoids were generally positively associated with LTL. Serum vitamin and carotenoid concentrations did not modify blood cadmium and LTL associations (P-interaction > 0.10).Conclusions: Results from this cross-sectional study suggest that exposure to cadmium and certain nutrients may be associated with LTL in US adults, but the serum concentrations of the vitamins and carotenoids evaluated did not modify cross-sectional associations between cadmium exposure and LTL.

The relationship between telomere length and beekeeping among Malaysians

The belief that beekeepers live longer than anyone else is present since ages. However, no research has been done to explore the longevity of life in beekeepers. Here, we investigated the telomere length in 30 male beekeepers and 30 male non-beekeepers and associated them with the longevity of life using Southern analysis of terminal restriction fragments (TRFs) generated by Hinf I/Rsa I digestion of human genomic DNA using TeloTAGGG Telomere Length Assay. Interestingly, we found that the telomere length of male beekeepers was significantly longer than those of male non-beekeepers with a p value of less than 0.05, suggesting that beekeepers may have longer life compared to non-beekeepers. We further found that the consumption of bee products for a long period and frequent consumption of bee products per day are associated with telomere length. An increase of year in consuming bee products is associated with a mean increase in telomere length of 0.258 kbp. In addition, an increase in frequency of eating bee products per day was also associated with a mean increase of 2.66 kbp in telomere length. These results suggested that bee products might play some roles in telomere length maintenance.

Tocopherol isoforms (α-, γ-, and δ-) show distinct capacities to control Nrf-2 and NfκB signaling pathways that modulate inflammatory response in Caco-2 intestinal cells

We recently showed that α-, γ-, and δ-tocopherols (Toc) were isoform dependent in modulating an inflammatory response in differentiated human Caco-2 intestinal cells. Here, we aim to investigate the relative capacity of Toc isoforms to modify the stress-activated NfκB and Nrf-2 signaling pathways that regulate the expression of pro-inflammatory cytokines and antioxidant enzymes, respectively, in this well-established in vitro model of the small intestine The modulation of IFNγ/phorbol myristate acetate (PMA)-induced inflammatory responses, determined by the expression of IL8 mRNA and protein, corresponded to the extent by which different Toc isoforms altered intracellular oxidative status in Caco-2 cells. α Toc was more effective at suppressing IFNγ/PMA-induced NfκB activation than γ-Toc, while δ-Toc was ineffective. On the other hand, only δ-Toc and to a lesser extent γ-Toc promoted IFNγ/PMA-induced Nrf-2 activation. Up-regulation of Nrf-2 by δ-Toc coincided with a decrease in GSH/GSSG ratio, thus pointing to pro-oxidant activity of δ-Toc isoform in IFNγ/PMA-stimulated Caco-2 cells. The induction of oxidative stress in IFNγ/PMA-treated cells by δ-Toc was lowered (P < 0.05) in the presence of ascorbic acid. Ascorbic acid also enabled a greater suppression of IL8 secretion than when cells were treated with δ-Toc isoform alone. Our findings show that δ-Toc uniquely promoted oxidative stress which translated to Toc isoform-specific modulation of the stress-activated Nrf-2 and NfκB signaling pathway and an influence on IL8 expression.

Correlation between anthropometric measurement, lipid profile, dietary vitamins, serum antioxidants, lipoprotein (a) and lipid peroxides in known cases of 345 elderly hypertensive South Asian aged 56-64 y-A hospital based study

OBJECTIVE

To address the association of dietary vitamins, anthropometric profile, lipid profile, antioxidant enzymes and lipid peroxidation in hypertensive participant compared with normotensive healthy controls.

METHODS

Dietary intake of vitamins was assessed by 131 food frequency questionnaire items in both hypertensive participants and normotensive age-sex matched healthy controls. The associated changes in serum antioxidants and lipid peroxidation were also assessed along with lipid profile and anthropometric measurements in both groups of subjects under study.

RESULTS

Dietary vitamins intake was higher in hypertensive participants excepting for vitamin B2 and ascorbic acid compared to normotensive controls. Anthropometric variables in the hypertensive showed significant differences in weight, body mass index, waist circumference, hip circumference, waist-hip ratio and mid-arm circumference. The total cholesterol, low-density lipoprotein cholesterol, triglyceride were significantly higher (P<0.001) in hypertensive except high-density lipoprotein cholesterol which was significantly higher (P<0.001) in normotensive. The serum endogenous antioxidants and enzyme antioxidants were significantly decreased in hypertensive except serum albumin levels compared to normotensive along with concomitant increase in serum lipoprotein (a) malondialdehyde and conjugated diene levels.

CONCLUSIONS

Based on the observations, our study concludes that hypertension is caused due to interplay of several confounding factors namely anthropometry, lipid profile, depletion of endogenous antioxidants and rise in oxidative stress.

Daily kiwifruit consumption did not improve blood pressure and markers of cardiovascular function in men with hypercholesterolemia

Increasing fruit and vegetable consumption is a key lifestyle modification in the prevention and treatment of hypertension. Kiwifruit has previously been shown to have favorable effects on blood pressure (BP), likely through inhibiting angiotensin I-converting enzyme activity. We hypothesized that the replacement of 2 fruit servings in a healthy diet with 2 green kiwifruit a day would significantly improve BP and other markers of cardiovascular function, including heart rate, stroke volume, cardiac output, and total peripheral resistance, in a group of hypercholesterolemic men. Using a controlled cross-over study design, 85 subjects completed a 4-week healthy diet run-in period before randomization to one of two 4-week intervention sequences in which they either consumed 2 green kiwifruit a day plus a healthy diet (intervention) or consumed a healthy diet alone (control). Blood pressure and other measures of cardiovascular function (using a Finometer MIDI [Finapres Medical Systems B.V, Amsterdam, The Netherlands] and standard oscillometric device) and anthropometric measurements were taken before and at the end of the treatment periods. A physical activity questionnaire was completed during the last visit. Subjects were found to be predominantly normotensive (43.5%) or prehypertensive (50.6%) and quite physically active (>30 minutes of moderate to vigorous physical activity/day in >80% subjects). No significant differences were seen for BP or any of the other markers, including heart rate, stroke volume, cardiac output, and total peripheral resistance. In conclusion, in this hypercholesterolemic, nonhypertensive group, no beneficial effects on BP or other markers of cardiovascular function were seen when consuming 2 kiwifruit a day against the background of a healthy diet.

Fruit and vegetable intake and risk of cardiovascular disease

A high intake of fruit and vegetables (FV) has been shown to be associated with reduced risk of a number of chronic diseases, including CVD. This review aims to provide an overview of the evidence that increased FV intake reduces risk of CVD, focusing on studies examining total FV intake. This evidence so far available is largely based on prospective cohort studies, with meta-analyses demonstrating an association between increased FV intake and reduced risk of both CHD and stroke. Controlled intervention trials examining either clinical or cardiovascular risk factor endpoints are scarce. However, such trials have shown that an increase in FV consumption can lower blood pressure and also improve microvascular function, both of which are commensurate with a reduced risk of CVD. The effects of increased FV consumption on plasma lipid levels, risk of diabetes and body weight have yet to be firmly established. In conclusion, evidence that FV consumption reduces the risk of CVD is so far largely confined to observational epidemiology, with further intervention studies required.

Nutritional recommendations for cardiovascular disease prevention

Lifestyle factors, including nutrition, play an important role in the etiology of Cardiovascular Disease (CVD). This position paper, written by collaboration between the Israel Heart Association and the Israel Dietetic Association, summarizes the current, preferably latest, literature on the association of nutrition and CVD with emphasis on the level of evidence and practical recommendations. The nutritional information is divided into three main sections: dietary patterns, individual food items, and nutritional supplements. The dietary patterns reviewed include low carbohydrate diet, low-fat diet, Mediterranean diet, and the DASH diet. Foods reviewed in the second section include: whole grains and dietary fiber, vegetables and fruits, nuts, soy, dairy products, alcoholic drinks, coffee and caffeine, tea, chocolate, garlic, and eggs. Supplements reviewed in the third section include salt and sodium, omega-3 and fish oil, phytosterols, antioxidants, vitamin D, magnesium, homocysteine-reducing agents, and coenzyme Q10.

Effect of beta-carotene on oxidative stress and expression of cardiac connexin 43

BACKGROUND

Intervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown.

OBJECTIVE

Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts.

METHODS

Wistar rats, weighing approximately 100 g, were allocated in two groups: CONTROL GROUP (n=30), that received the diet routinely used in our laboratory, and Beta-Carotene Group (n = 28), which received beta-carotene (in crystal form, added and mixed to the diet) at a dose of 500 mg of beta-carotene/kg of diet. The animals received the treatment until they reached 200-250 g, when they were sacrificed. Samples of blood, liver and heart were collected to perform Western blotting and immunohistochemistry for connexin 43; morphometric studies, dosages of beta-carotene by high-performance liquid chromatography as well as reduced glutathione, oxidized glutathione and lipids hydroperoxides were performed by biochemical analysis.

RESULTS

Beta-carotene was detected only in the liver of Beta-Carotene Group animals (288 ± 94.7 µg/kg). Levels of reduced/oxidized glutathione were higher in the liver and heart of Beta-Carotene Group animals (liver -

CONTROL GROUP

42.60 ± 1.62; liver - Beta-Carotene Group: 57.40 ± 5.90; p = 0.04; heart: -

CONTROL GROUP

117.40 ± 1.01; heart - Beta-Carotene Group: 121.81 ± 1.32 nmol/mg protein; p = 0.03). The content of total connexin 43 was larger in Beta-Carotene Group.

CONCLUSION

Beta-carotene demonstrated a positive effect, characterized by the increase of intercellular communication and improvement of anti-oxidizing defense system. In this model, mechanism does not explain the increased mortality rate observed with the beta-carotene supplementation in clinical studies.

New concepts in diabetic embryopathy

Diabetes mellitus is responsible for nearly 10% of fetal anomalies in diabetic pregnancies. Although aggressive perinatal care and glycemic control are available in developed countries, the birth defect rate in diabetic pregnancies remains higher than that in the general population. Major cellular activities (ie, proliferation and apoptosis) and intracellular metabolic conditions (ie, nitrosative, oxidative, and endoplasmic reticulum stress) have been shown to be associated with diabetic embryopathy using animal models. Translating advances made in animal studies into clinical applications in humans requires collaborative efforts across the basic research, preclinical, and clinical communities.

The impact of dietary counselling during pregnancy on vitamin intake and status of women and their children

We aimed here to assess the impact of dietary counselling during pregnancy on dietary intake of vitamins and the vitamin status of women and their children. At the first trimester of pregnancy, 89 women from allergic families were randomized to a control group (n = 45) or to receive individual dietary counselling (n = 44). Women's vitamin intakes and serum concentrations were analyzed during and after pregnancy. Further, vitamin concentrations were measured from breast milk and infant serum at one month of age. The study is registered as clinical study (NCT00167000; section 3, http://www.clinicaltrials.gov ). Dietary counselling resulted in a higher intake of beta-carotene and vitamin E compared to controls. Further, in women lower serum beta-carotene and higher colostrum vitamin A concentrations were found in the intervention group compared to controls. Dietary counselling during pregnancy improves women's vitamin intakes but does not provide unambiguous effects on vitamin status of women or children.

Hass avocado composition and potential health effects

Hass avocados, the most common commercial avocado cultivars in the world, contain a variety of essential nutrients and important phytochemicals. Although the official avocado serving is one-fifth of a fruit (30 g), according to NHANES analysis the average consumption is one-half an avocado (68 g), which provides a nutrient and phytochemical dense food consisting of the following: dietary fiber (4.6 g), total sugar (0.2 g), potassium (345 mg), sodium (5.5 mg), magnesium (19.5 mg), vitamin A (43 μg), vitamin C (6.0 mg), vitamin E (1.3 mg), vitamin K1 (14 μg), folate (60 mg), vitamin B-6 (0.2 mg), niacin (1.3 mg), pantothenic acid (1.0 mg), riboflavin (0.1 mg), choline (10 mg), lutein/zeaxanthin (185 μg), phytosterols (57 mg), and high-monounsaturated fatty acids (6.7 g) and 114 kcals or 1.7 kcal/g. The avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat soluble vitamins and phytochemicals from the avocado or other fruits and vegetables, naturally low in fat, which are consumed with avocados. There are eight preliminary clinical studies showing that avocado consumption helps support cardiovascular health. Exploratory studies suggest that avocados may support weight management and healthy aging.

Antioxidant and antitumor activities of selenium- and zinc-enriched oyster mushroom in mice

Selenium and zinc are well-known essential trace elements with potent biological functions. However, the possible health benefits of the combined administration of dietary selenium and zinc have not been studied extensively. In this study, we prepared selenium- and zinc-enriched mushrooms (SZMs) containing increased levels of selenium and zinc. The effects of SZMs on antioxidant and antitumor activities were evaluated. Mice were fed with either a control diet or a diet supplemented with SZMs or sodium selenite and zinc sulfate for 6 weeks. Antioxidant capacity was investigated by measuring the activities of antioxidant enzymes and the levels of lipid peroxide products. Results showed that treatment with SZMs significantly increased the activities of glutathione peroxidase (GPx) and superoxide dismutase and decreased the levels of malondialdehyde and lipofuscin. Furthermore, using a mouse model of lung tumors, we found that SZMs significantly decreased the number of tumor nodes with an increase in the activity of GPx. SZMs had a greater effect on the increase in both antioxidant and antitumor activities than did sodium selenite and zinc sulfate. These findings suggest that SZMs may be effective for improving antioxidant capacity and preventing tumors.

Optimized rapeseed oil enriched with healthy micronutrients: a relevant nutritional approach to prevent cardiovascular diseases. Results of the Optim'Oils randomized intervention trial

Rapeseeds are naturally rich in cardioprotective micronutrients but refining leads to substantial losses or the production of undesirable compounds. The Optim'Oils European project proposed innovative refining conditions to produce an optimized rapeseed oil enriched in micronutrients and low in trans linolenic acid. We aimed to investigate cardioprotective properties of this Optimized oil. In a randomized, double-blind, controlled, cross-over study, 59 healthy normolipidaemic men consumed either Optimized or Standard rapeseed oils (20 g/d) and margarines (22 g/d) for 3 weeks. The Optimized oil reduced the trans FA concentration (p=0.009) and increased the contents of alpha-tocopherol (p=0.022) and coenzyme Q10 (p<0.001) in comparison with the Standard oil. Over the 3-week trial, Total-/HDL-cholesterol and LDL-/HDL-cholesterol were increased by 4% (p<0.05) with the Standard oil consumption whereas none of them rose with the Optimized rapeseed oil which increased the HDL-cholesterol and ApoA1 plasma content (+2%, NS and +3%, p<0.05 respectively). The effects observed on the plasma HDL-cholesterol levels (p=0.059), the Total-/HDL-cholesterol ratio (p=0.092), and on the ApoA1 concentrations (p=0.060) suggest an improvement of the cholesterol profile with the Optimized rapeseed oil. Finally, the Optimized oil reduced the plasma content of LDLox (-6%, NS), this effect being significantly different from the Standard oil (p=0.050). In conclusion, reasonable intake of an Optimized rapeseed oil resulting from innovative refining processes and enriched in cardioprotective micronutrients represent a relevant nutritional approach to prevent the risk of cardiovascular diseases by improving the cholesterol profile and reducing LDL oxidation.

The PPAR-RXR Transcriptional Complex in the Vasculature

The peroxisome proliferator-activated receptors (PPARs) and the retinoid X receptors (RXRs) are ligand-activated transcription factors that coordinately regulate gene expression. This PPAR-RXR transcriptional complex plays a critical role in energy balance, including triglyceride metabolism, fatty acid handling and storage, and glucose homeostasis: processes whose dysregulation characterize obesity, diabetes, and atherosclerosis. PPARs and RXRs are also involved directly in inflammatory and vascular responses in endothelial and vascular smooth muscle cells. New insights into fundamental aspects of PPAR and RXR biology, and their actions in the vasculature, continue to appear. Although RXRs are obligate heterodimeric partners for PPAR action, the part that RXRs, and their endogenous retinoid mediators, exert in the vessel wall is less well understood. Biological insights into PPAR-RXRs may help inform interpretation of clinical trials with synthetic PPAR agonists and prospects for future PPAR therapeutics. Importantly, the extensive data establishing a key role for PPARs and RXRs in energy balance, inflammation, and vascular biology stands separately from the clinical experience with any given synthetic PPAR agonist. Both the basic science data and the clinical experience with PPAR agonists identify the need to better understand these important transcriptional regulators.

Diet, nutrition and telomere length

The ends of human chromosomes are protected by DNA-protein complexes termed telomeres, which prevent the chromosomes from fusing with each other and from being recognized as a double-strand break by DNA repair proteins. Due to the incomplete replication of linear chromosomes by DNA polymerase, telomeric DNA shortens with repeated cell divisions until the telomeres reach a critical length, at which point the cells enter senescence. Telomere length is an indicator of biological aging, and dysfunction of telomeres is linked to age-related pathologies like cardiovascular disease, Parkinson disease, Alzheimer disease and cancer. Telomere length has been shown to be positively associated with nutritional status in human and animal studies. Various nutrients influence telomere length potentially through mechanisms that reflect their role in cellular functions including inflammation, oxidative stress, DNA integrity, DNA methylation and activity of telomerase, the enzyme that adds the telomeric repeats to the ends of the newly synthesized DNA.

The Role of Antioxidant Vitamins in Cardiovascular Disease

Objective:

To review the current data on the role of antioxidant vitamins in cardiovascular disease.

Data Sources:

Articles were obtained from a MEDLINE search covering all years. Terms used in the search included combinations of antioxidant, vitamin, vitamin E, vitamin C, beta-carotene, and cardiovascular disease. Reference lists from articles were examined for additional references.

Study Selection and Data Extraction:

Randomized clinical trials were selected and evaluated for study design and data obtained. Observational studies, meta-analyses, and basic science articles were also reviewed for background.

Data Synthesis:

The use of dietary supplements, including vitamins, minerals, and herbal products, is common among patients in the US. Vitamin E, vitamin C, and beta-carotene are all supplements with reported antioxidant activity. Because oxidative stress has been implicated in the development of cardiovascular disease, there has been significant research at the basic science level as well as observational studies and randomized placebo-controlled trials examining the potential impact of vitamin E, vitamin C, and beta-carotene in the prevention and treatment of cardiovascular disease. While basic science data and data from observational studies have identified benefit from antioxidant vitamin supplementation, randomized clinical trials have failed to support a role for antioxidant vitamin supplementation in the prevention or treatment of cardiovascular disease.

Conclusions:

Data from randomized clinical trials do not support the use of antioxidant vitamins in cardiovascular disease. Therefore, antioxidant vitamins should not be recommended to patients for prevention or treatment of cardiovascular disease.

4-hydroxy-2-nonenal protects against cardiac ischemia-reperfusion injury via the Nrf2-dependent pathway

Reactive oxygen species (ROS) attack polyunsaturated fatty acids of the membrane and trigger lipid peroxidation, which results in the generation of alpha,beta-unsaturated aldehydes, such as 4-hydroxy-2-nonenal (4-HNE). There is compelling evidence that high concentrations of aldehydes are responsible for much of the damage elicited by cardiac ischemia-reperfusion injury, while sublethal concentrations of aldehydes stimulate stress resistance pathways, to achieve cardioprotection. We investigated the mechanism of cardioprotection mediated by 4-HNE. For cultured cardiomyocytes, 4-HNE was cytotoxic at higher concentrations (>or=20 microM) but had no appreciable cytotoxicity at lower concentrations. Notably, a sublethal concentration (5muM) of 4-HNE primed cardiomyocytes to become resistant to cytotoxic concentrations of 4-HNE. 4-HNE induced nuclear translocation of transcription factor NF-E2-related factor 2 (Nrf2), and enhanced the expression of gamma-glutamylcysteine ligase (GCL) and the core subunit of the Xc(-) high-affinity cystine transporter (xCT), thereby increasing 1.45-fold the intracellular GSH levels. Cardiomyocytes treated with either Nrf2-specific siRNA or the GCL inhibitor l-buthionine sulfoximine (BSO) were less tolerant to 4-HNE. Moreover, the cardioprotective effect of 4-HNE pretreatment against subsequent glucose-free anoxia followed by reoxygenation was completely abolished in these cells. Intravenous administration of 4-HNE (4 mg/kg) activated Nrf2 in the heart and increased the intramyocardial GSH content, and consequently improved the functional recovery of the left ventricle following ischemia-reperfusion in Langendorff-perfused hearts. This cardioprotective effect of 4-HNE was not observed for Nrf2-knockout mice. In summary, 4-HNE activates Nrf2-mediated gene expression and stimulates GSH biosynthesis, thereby conferring on cardiomyocytes protection against ischemia-reperfusion injury.

Vitaminas e minerais com propriedades antioxidantes e risco cardiometabólico: controvérsias e perspectivas

No processo celular de obtenção de energia, são gerados compostos chamados espécies reativas de oxigênio (ERO) que, em excesso, podem causar danos celulares. Estresse oxidativo resulta do desequilíbrio no estado de óxido-redução a favor da oxidação. Dos mecanismos de defesa antioxidante, participam enzimas endógenas e algumas vitaminas e minerais. A vitamina E encontra-se no plasma e na partícula de LDL, protegendo lipídeos da oxidação. Estudos observacionais relataram associação inversa entre ingestão de vitamina E e risco cardiometabólico (RCM). Entretanto, ensaios clínicos não comprovaram a eficácia de sua suplementação nos desfechos cardiometabólicos. A vitamina C participa do sistema de regeneração da vitamina E, mantendo o potencial antioxidante plasmático. Dados sobre os benefícios de sua suplementação na redução do risco cardiometabólico são inconclusivos. A atividade antioxidante dos carotenoides é responsável, em parte, por seu papel protetor contra doenças cardiovasculares e cânceres. A suplementação desse nutriente também não trouxe resultados consistentes no que se refere à redução do RCM. A participação do zinco e do selênio na defesa antioxidante vem sendo estudada mais recentemente, mas a sua suplementação em indivíduos com níveis séricos normais e ingestão adequada na dieta desses minerais não parece ser necessária. De um modo geral, há muita controvérsia sobre o papel desses micronutrientes no RCM. Estudos epidemiológicos sugerem que o consumo de substâncias antioxidantes provenientes da dieta ou dietas ricas em frutas e hortaliças diminui o RCM. Mais estudos são necessários antes de se recomendar o uso de antioxidantes isolados na forma de suplementos para tal finalidade.

Glutathione, vitamin E and oxidative stress in coronary artery disease: relevance of age and gender

BACKGROUND

Observational studies suggest that low levels of antioxidants are associated with high risk for coronary artery disease (CAD). We investigated whether the biomarkers of oxidative balance undergo the same modifications in all CAD patient groups, regardless of gender and age.

MATERIALS AND METHODS

One hundred sixty-eight CAD patients and 107 healthy controls were assayed for plasma levels of reduced glutathione (GSH), alpha- and gamma-tocopherol (alpha- and gamma-T) as endogenous antioxidants. A damage score (DS), representative of oxidative stress status, was calculated. ANCOVA models were used to test the association between antioxidants, DS and CAD and its modulation by age and gender.

RESULTS

The DS was higher in CAD than in controls. GSH levels, were lower in CAD patients (mean +/- SEM: 57.61 +/- 1.87 micromol 10 g(-1) haemoglobin vs. 68.55 +/- 2.23 in controls, P < 0.0006) in males and in older subjects. Levels of other antioxidants exhibited a complex pattern. Overall, no difference was found in alpha- and gamma-T contents between CAD and controls, but lower alpha-T values were observed in CAD females. A significant interaction between CAD status and gender was observed (P = 0.003).

CONCLUSIONS

Our study shows that the involvement of antioxidants in CAD is related to patients' characteristics. These findings may be relevant in planning antioxidant therapies.