Dietary Flavanols: A Review of Select Effects on Vascular Function, Blood Pressure, and Exercise Performance

The Effect of Dark Chocolate Consumption on Arterial Function in Endurance Male Runners: Prospective Cohort Study

Foods rich in polyphenols have beneficial effects on health. This study aimed to examine the impact of dark chocolate on endurance runners' arterial function. Forty-six male amateur runners, aged 25-55, participated. The initial assessments included clinical testing, arterial stiffness measurements, and a cardiopulmonary exercise test. The participants then consumed 50 g of dark chocolate (70% cocoa) daily for two weeks, maintaining their usual training routine. After this period, the baseline assessment was repeated. The results showed significant improvements. Pulse wave velocity decreased by 11.82% (p < 0.001), and augmentation index by 19.47% (p < 0.001). Systolic brachial blood pressure reduced by 2.12% (p < 0.05), diastolic by 2.79% (p < 0.05), and mean pressure by 2.41% (p < 0.05). Central arterial pressure also decreased, with systolic by 1.24% (p < 0.05), diastolic by 2.80% (p < 0.05), and mean pressure by 2.43% (p < 0.05). Resting heart rate increased by 4.57% (p < 0.05) and left ventricular ejection time decreased by 4.89% (p < 0.05), particularly in athletes over 40. Exercise time increased by 2.16% (p < 0.05), heart rate (max) by 1.15% (p < 0.05), VO2max by 2.31% (p < 0.05), and anaerobic threshold shifted by 6.91% (p < 0.001) in exercise time and 6.93% (p < 0.001) in VO2max. In conclusion, dark chocolate improves arterial function in endurance runners, enhancing vascular health.

A decade of advances in the study of buckwheat for organic farming and agroecology (2013-2023)

During the last decade, research has shown the environment and human health benefits of growing buckwheat (Fagopyrum spp.). This comprehensive review aims to summarize the major advancements made in the study of buckwheat from 2013 to 2023, focusing on its agronomic characteristics, nutritional value, and potential applications in sustainable agriculture. The review examines the diverse applications of buckwheat in organic and agroecological farming systems, and discusses the ability of buckwheat to control weeds through allelopathy, competition, and other sustainable farming methods, such as crop rotation, intercropping and green manure, while improving soil health and biodiversity. The review also explores the nutritional value of buckwheat. It delves into the composition of buckwheat grains, emphasizing their high protein content, and the presence of essential amino acids and valuable micronutrients, which is linked to health benefits such as lowering cholesterol levels, controlling diabetes and acting against different types of cancer, among others. Finally, the review concludes by highlighting the gaps in current knowledge, and proposing future research directions to further optimize buckwheat production in organic or agroecological farming systems. It emphasizes the need for interdisciplinary collaboration, and the integration of traditional knowledge with modern scientific approaches to unlock the full potential of buckwheat as a sustainable crop.

Association between dietary flavonol intake and mortality risk in the U.S. adults from NHANES database

Using updated National Health and Nutrition Examination Survey (NHANES) follow-up data, and a large nationwide representative sample of adult U.S. citizens, the aim of this study was to explore the relationship between dietary flavonol intake, all-cause and cause-specific mortality risks. In this prospective cohort study based on NHANES (2007-2008, 2009-2010, and 2017-2018), a total of 11,679 participants aged 20 years and above were evaluated. The amount and type of food taken during a 24-h dietary recall were used to estimate dietary flavonol intake, which includes total flavonol, isorhamnetin, kaempferol, myricetin, and quercetin. Each analysis of the weighted data was dealt with in accordance with the NHANES reporting requirements' intricate stratification design. The Cox proportional risk regression model or Fine and Gray competing risks regression model were applied to evaluate all-cause and cause-specific mortality risks, respectively. The follow-up period was calculated using the time interval between the baseline and the death date or December 31, 2019 (whichever occurs first). Each data analysis was performed between October 1, 2023, and October 22, 2023. Dietary flavonol intake included total flavonol, isorhamnetin, kaempferol, myricetin, and quercetin. Up to December 31, 2019, National Death Index (NDI) mortality data were used to calculate mortality from all causes as well as cause-specific causes. A total of 11,679 individuals, which represents 44,189,487 U.S. non-hospitalized citizens, were included in the study; of these participants, 49.78% were male (n = 5816), 50.22% were female (n = 5, 863); 47.56% were Non-Hispanic White (n = 5554), 18.91% were Non-Hispanic Black (n = 2209), 16.23% were Mexican American (n = 1895), and 17.30% were other ethnicity (n = 2021); The mean [SE] age of the sample was 46.93 [0.36] years, with a median follow-up of 7.80 years (interquartile range, 7.55-8.07 years). After adjusting covariates, Cox proportional hazards models and fine and gray competing risks regression models for specific-cause mortality demonstrated that total flavonol intake was associated with all-cause (HR 0.64, 95% CI 0.54-0.75), cancer-specific (HR 0.45, 95% CI 0.28-0.70) and CVD-specific (HR 0.67, 95% CI 0.47-0.96) mortality risks; isorhamnetin intake was associated with all-cause (HR 0.72, 95% CI 0.60-0.86), and cancer-specific (HR 0.62, 95% CI 0.46-0.83) mortality risks; kaempferol intake was associated with all-cause (HR 0.74, 95% CI 0.63-0.86), and cancer-specific (HR 0.62, 95% CI 0.40-0.97) mortality risks; myricetin intake was associated with all-cause (HR 0.77, 95% CI 0.67-0.88), AD-specific (HR 0.34, 95% CI 0.14-0.85), and CVD-specific (HR 0.61, 95% CI 0.47-0.80) mortality risks; quercetin intake was associated with all-cause (HR 0.66, 95% CI 0.54-0.81), cancer-specific (HR 0.54, 95% CI 0.35-0.84), and CVD-specific (HR 0.61, 95% CI 0.40-0.93) mortality risks; there was no correlation observed between dietary flavonol intake and DM-specific mortality. According to the current study, all-cause, AD, cancer, and CVD mortality risks declined with increased dietary flavonoid intake in the U.S. adults. This finding may be related to the anti-tumor, anti-inflammatory, and anti-oxidative stress properties of flavonol.

A Compressive Review on Source, Toxicity and Biological Activity of Flavonoid

Flavonoids are biologically active chemicals in various fruits, plants, vegetables, and leaves, which have promising uses in medicinal science. The health properties of these natural chemicals are widely accepted, and efforts are underway to extract the specific components referred to as flavonoids. Flavonoids demonstrate a diverse range of bio-activities, anticancer, antioxidant activity, anti-cholinesterase activity, antiinflammatory activity, antimalarial activity, antidiabetic activity, neurodegenerative disease, cardiovascular effect, hepatoprotective effects, and antiviral and antimicrobial activity. This study aims to examine the prevailing trends in flavonoid investigation studies, elucidate the activity of flavonoids, examine their various functions and uses, assess the potential of flavonoids as preventive medications for chronic diseases, and outline future research opportunities in this field. This review explores the diverse functions of flavonoids in preventing and managing various diseases.

A randomized, placebo-controlled trial evaluating the safety of excessive administration of kaempferol aglycone

Kaempferol (KMP) is an important flavonoid in many fruits and vegetables. Preclinical studies on KMP have reported its pharmacological effects, including antimicrobial, antioxidant, anti-inflammatory, antitumor, antidiabetic, myocardial protective, and neuroprotective effects. Additionally, some epidemiological studies have revealed a negative association between the consumption of KMP-containing foods and the risk of developing several disorders, such as cancer and cardiovascular diseases. Thus, although a large body of literature has demonstrated the benefits of KMP supplementation, there are no reports of clinical trials evaluating the safety of KMP aglycone administration or KMP aglycone-rich food consumption. The purpose of this study was to evaluate the safety of a high dose of KMP aglycone by administrating KMP aglycone-containing supplements to healthy adults. This study had a randomized, double-blind, placebo-controlled design and a 4-week duration. Participants were randomly allocated to the KMP (n = 24) or placebo (n = 24) group. For 4 weeks, the KMP group received a capsule containing 50-mg KMP daily, a dose approximately five times higher than the estimated human dietary intake. The placebo group received a capsule containing cornstarch-based powder daily. The general toxicity parameters were evaluated by examining the characteristics of the participants, hematological and blood biochemical parameters, general urinalysis, qualitative urine tests, and adverse events. No clinical changes were observed in anthropometric and blood pressure measurements or blood and urine parameters in the KMP group compared to those in the placebo group. Furthermore, no adverse events owing to KMP aglycone administration occurred. The study results revealed that the consumption of 50-mg KMP aglycone daily for 4 weeks is safe in healthy adults.

Flavonoids: Overview of Biosynthesis, Biological Activity, and Current Extraction Techniques

Recently, increased attention has been paid to natural sources as raw materials for the development of new added-value products. Flavonoids are a large family of polyphenols which include several classes based on their basic structure: flavanones, flavones, isoflavones, flavonols, flavanols, and anthocyanins. They have a multitude of biological properties, such as anti-inflammatory, antioxidant, antiviral, antimicrobial, anticancer, cardioprotective, and neuroprotective effects. Current trends of research and development on flavonoids relate to identification, extraction, isolation, physico-chemical characterization, and their applications to health benefits. This review presents an up-to-date survey of the most recent developments in the natural flavonoid classes, the biological activity of representative flavonoids, current extraction techniques, and perspectives.

Upcycling flavanol-rich Chardonnay and Pinot noir grape thinned clusters as potentially functional food ingredients in cocoa-based products

In California, over 3.4 million tons of wine grapes were crushed in 2020 while every year roughly 20% of the grape mass goes unused. Grape cluster thinning at veraison, a common agricultural practice to ensure color homogeneity in wine grapes, adds to the production costs and generates substantial on-farm loss during grapevine cultivation in which the health-promoting values of thinned clusters (unripe grapes) are usually overlooked. In particular, the health-promoting properties of flavanol monomers, specifically (+)-catechin and (-)-epicatechin, and their oligomeric procyanidins, have been extensively studied in cocoa and chocolate but not so much in grape thinned clusters in recent epidemiology studies. As part of the important agricultural by-products upcycling effort, the current study compared thinned clusters from Chardonnay and Pinot noir, two premium wine grape varieties cultivated in California, to a traditionally Dutch (alkalized) cocoa powder that has been widely used in food applications. Thinned cluster fractions from Chardonnay and Pinot noir grapes grown in the North Coast of California showed much higher concentrations of flavanol monomers and procyanidins, with 208.8-763.5 times more (+)-catechin, 3.4-19.4 times more (-)-epicatechin, and 3.8-12.3 times more procyanidins (by degree of polymerization DP 1-7) than those in the traditionally Dutch cocoa powder. These flavanol-rich thinned clusters that are also considered as plant-based natural products suggested great potential to be functional ingredients in cocoa-based products-which have been ubiquitously perceived as flavanol-rich products by consumers-to enhance their overall dietary flavanol content.

Effect of hypobaric hypoxia on the fiber type transition of skeletal muscle: a synergistic therapy of exercise preconditioning with a nanocurcumin formulation

Hypobaric hypoxia (HH) leads to various adverse effects on skeletal muscles, including atrophy and reduced oxidative work capacity. However, the effects of HH on muscle fatigue resistance and myofiber remodeling are largely unexplored. Therefore, the present study aimed to explore the impact of HH on slow-oxidative fibers and to evaluate the ameliorative potential of exercise preconditioning and nanocurcumin formulation on muscle anti-fatigue ability. C2C12 cells (murine myoblasts) were used to assess the effect of hypoxia (0.5%, 24 h) with and without the nanocurcumin formulation (NCF) on myofiber phenotypic conversion. To further validate this hypothesis, male Sprague Dawley rats were exposed to a simulated HH (7620 m) for 7 days, along with NCF administration and/or exercise training. Both in vitro and in vivo studies revealed a significant reduction in slow-oxidative fibers (p < 0.01, 61% vs. normoxia control) under hypoxia. There was also a marked decrease in exhaustion time (p < 0.01, 65% vs. normoxia) in hypoxia control rats, indicating a reduced work capacity. Exercise preconditioning along with NCF supplementation significantly increased the slow-oxidative fiber proportion and exhaustion time while maintaining mitochondrial homeostasis. These findings suggest that HH leads to an increased transition of slow-oxidative fibers to fast glycolytic fibers and increased muscular fatigue. Administration of NCF in combination with exercise preconditioning restored this myofiber remodeling and improved muscle anti-fatigue ability.

Role of polyphenolic compounds and their nanoformulations: a comprehensive review on cross-talk between chronic kidney and cardiovascular diseases

Chronic kidney disease (CKD) affects a huge portion of the world's population and frequently leads to cardiovascular diseases (CVDs). It might be because of common risk factors between chronic kidney disease and cardiovascular diseases. Renal dysfunction caused by chronic kidney disease creates oxidative stress which in turn leads to cardiovascular diseases. Oxidative stress causes endothelial dysfunction and inflammation in heart which results in atherosclerosis. It ends in clogging of veins and arteries that causes cardiac stroke and myocardial infarction. To develop an innovative therapeutic approach and new drugs to treat these diseases, it is important to understand the pathophysiological mechanism behind the CKD and CVDs and their interrelationship. Natural phytoconstituents of plants such as polyphenolic compounds are well known for their medicinal value. Polyphenols are plant secondary metabolites with immense antioxidant properties, which can protect from free radical damage. Nowadays, polyphenols are generating a lot of buzz in the scientific community because of their potential health benefits especially in the case of heart and kidney diseases. This review provides a detailed account of the pathophysiological link between CKD and CVDs and the pharmacological potential of polyphenols and their nanoformulations in promoting cardiovascular and renal health.

The mechanisms of wine phenolic compounds for preclinical anticancer therapeutics

Background

Wine is one of the oldest and most popular drinks worldwide, which is rich in phenolic compounds. Epidemiological studies show that moderate consumption of wine can reduce the risk of certain diseases, and this effect is attributed to its phenolic compounds.

Objective

The objective of this review was to elaborate the effects of wine-derived phenolic compounds for preclinical anticancer therapeutics and their major mechanisms.

Methods

In this review, we discuss the classification and content of common phenolic compounds in wine and summarize previous studies that have evaluated the anticancer properties of wine-derived phenolic compounds and their mechanisms.

Results

Wine-derived phenolic compounds have been proven to participate in several mechanisms against cancers, including deoxyribonucleic acid damage, oxidative stress, cell proliferation, cell cycle arrest, cell apoptosis, autophagy, cell invasion and metastasis, immunity and metabolism, regulation of multiple signaling molecules, and gene expression. However, the exact anticancer mechanisms of the phenolic compounds in wine need to be further investigated.

Conclusion

Wine-derived phenolic compounds are promising chemoprotective and chemotherapeutic agents for cancer.

Impact of nutraceuticals on markers of systemic inflammation: Potential relevance to cardiovascular diseases - A position paper from the International Lipid Expert Panel (ILEP)

Inflammation is a marker of arterial disease stemming from cholesterol-dependent to -independent molecular mechanisms. In recent years, the role of inflammation in atherogenesis has been underpinned by pharmacological approaches targeting systemic inflammation that have led to a significant reduction in cardiovascular disease (CVD) risk. Although the use of nutraceuticals to prevent CVD has largely focused on lipid-lowering (e.g, red-yeast rice and omega-3 fatty acids), there is growing interest and need, especially now in the time of coronavirus pandemic, in the use of nutraceuticals to reduce inflammatory markers, and potentially the inflammatory CVD burden, however, there is still not enough evidence to confirm this. Indeed, diet is an important lifestyle determinant of health and can influence both systemic and vascular inflammation, to varying extents, according to the individual nutraceutical constituents. Thus, the aim of this Position Paper is to provide the first attempt at recommendations on the use of nutraceuticals with effective anti-inflammatory properties.

Benefits of Exercise and Astaxanthin Supplementation: Are There Additive or Synergistic Effects?

A healthy lifestyle is essential for maintaining physical and mental health. Health promotion, with a particular emphasis on regular exercise and a healthy diet, is one of the emerging trends in healthcare. However, the way in which exercise training and nutrients from dietary intake interact with each other to promote additive, synergistic, or antagonistic effects on physiological functions leading to health promotion, and the possible underlying biomolecular mechanisms of such interactions, remain poorly understood. A healthy diet is characterized by a high intake of various bioactive compounds usually found in natural, organic, and fresh foodstuffs. Among these bioactive compounds, astaxanthin (ASX), a red carotenoid pigment especially found in seafood, has been recognized in the scientific literature as a potential nutraceutical due to its antioxidant, anti-inflammatory, and neurotrophic properties. Therefore, scientists are currently exploring whether this promising nutrient can increase the well-known benefits of exercise on health and disease prevention. Hence, the present review aimed to compile and summarize the current scientific evidence for ASX supplementation in association with exercise regimes, and evaluate the additive or synergistic effects on physiological functions and health when both interventions are combined. The new insights into the combination paradigm of exercise and nutritional supplementation raise awareness of the importance of integrative studies, particularly for future research directions in the field of health and sports nutrition science.

Date Palm Fruit (Phoenix dactylifera): Effects on Vascular Health and Future Research Directions

Cardiovascular disease is a leading cause of death globally, presenting an immense public and economic burden. Studies on cardioprotective foods and their bioactive components are needed to address both personal and public health needs. Date fruit is rich in polyphenols, particularly flavonoids, certain micronutrients, and dietary fiber, which can impact vascular health, and have the potential to attenuate vascular disease in humans. Data from in vitro and animal studies report that consumption of date fruit or extracts can modulate select markers of vascular health, particularly plasma lipid levels including triglycerides and cholesterol, indices of oxidative stress and inflammation, but human data is scant. More investigation is needed to better characterize date polyphenols and unique bioactive compounds or fractions, establish safe and effective levels of intake, and delineate underlying mechanisms of action. Implementing scientific rigor in clinical trials and assessment of functional markers of vascular disease, such as flow-mediated dilation and peripheral arterial tonometry, along with gut microbiome profiles would provide useful information with respect to human health. Emerging data supports the notion that intake of date fruit and extracts can be a useful component of a healthy lifestyle for those seeking beneficial effects on vascular health.

Does Flavonoid Consumption Improve Exercise Performance? Is It Related to Changes in the Immune System and Inflammatory Biomarkers? A Systematic Review of Clinical Studies since 2005

Flavonoids are attracting increasing attention due to their antioxidant, cardioprotective, and immunomodulatory properties. Nevertheless, little is known about their role in exercise performance in association with immune function. This systematic review firstly aimed to shed light on the ergogenic potential of flavonoids. A search strategy was run using SCOPUS database. The returned studies were screened by prespecified eligibility criteria, including intervention lasting at least one week and performance objectively quantified, among others. Fifty-one studies (54 articles) met the inclusion criteria, involving 1288 human subjects, either physically untrained or trained. Secondly, we aimed to associate these studies with the immune system status. Seventeen of the selected studies (18 articles) assessed changes in the immune system. The overall percentage of studies reporting an improved exercise performance following flavonoid supplementation was 37%, the proportion being 25% when considering quercetin, 28% for flavanol-enriched extracts, and 54% for anthocyanins-enriched extracts. From the studies reporting an enhanced performance, only two, using anthocyanin supplements, focused on the immune system and found certain anti-inflammatory effects of these flavonoids. These results suggest that flavonoids, especially anthocyanins, may exert beneficial effects for athletes’ performances, although further studies are encouraged to establish the optimal dosage and to clarify their impact on immune status.

ACE Inhibitory and Antihypertensive Activities of Wine Lees and Relationship among Bioactivity and Phenolic Profile

Wine lees (WL) are by-products generated in the winemaking process. The aim of this study was to investigate the angiotensin-converting enzyme inhibitory (ACEi) activity, and the blood pressure (BP) lowering effect of WL from individual grape varieties. The relationship among their activities and phenolic profiles was also studied. Three WL, from Cabernet, Mazuela, and Garnacha grape varieties, were firstly selected based on their ACEi properties. Their phenolic profiles were fully characterized by UHPLC-ESI-Q-TOF-MS. Then, their potential antihypertensive effects were evaluated in spontaneously hypertensive rats (SHR). BP was recorded before and after their oral administrations (2, 4, 6, 8, 24, and 48 h) at a dose of 5 mL/kg bw. Cabernet WL (CWL) exhibited a potent antihypertensive activity, similar to that obtained with the drug Captopril. This BP-lowering effect was related to the high amount of anthocyanins and flavanols present in these lees. In addition, a potential hypotensive effect of CWL was discarded in normotensive Wistar-Kyoto rats. Finally, the ACEi and antihypertensive activities of CWL coming from a different harvest were confirmed. Our results suggest the potential of CWL for controlling arterial BP, opening the door to commercial use within the wine industry.

A Review of Strawberry Photobiology and Fruit Flavonoids in Controlled Environments

Rapid technology development in controlled environment (CE) plant production has been applied to a large variety of plants. In recent years, strawberries have become a popular fruit for CE production because of their high economic and nutritional values. With the widespread use of light-emitting diode (LED) technology in the produce industry, growers can manipulate strawberry growth and development by providing specific light spectra. Manipulating light intensity and spectral composition can modify strawberry secondary metabolism and highly impact fruit quality and antioxidant properties. While the impact of visible light on secondary metabolite profiles for other greenhouse crops is well documented, more insight into the impact of different light spectra, from UV radiation to the visible light spectrum, on strawberry plants is required. This will allow growers to maximize yield and rapidly adapt to consumer preferences. In this review, a compilation of studies investigating the effect of light properties on strawberry fruit flavonoids is provided, and a comparative analysis of how light spectra influences strawberry's photobiology and secondary metabolism is presented. The effects of pre-harvest and post-harvest light treatments with UV radiation and visible light are considered. Future studies and implications for LED lighting configurations in strawberry fruit production for researchers and growers are discussed.

Nutraceutical Properties of Polyphenols against Liver Diseases

Current food tendencies, suboptimal dietary habits and a sedentary lifestyle are spreading metabolic disorders worldwide. Consequently, the prevalence of liver pathologies is increasing, as it is the main metabolic organ in the body. Chronic liver diseases, with non-alcoholic fatty liver disease (NAFLD) as the main cause, have an alarming prevalence of around 25% worldwide. Otherwise, the consumption of certain drugs leads to an acute liver failure (ALF), with drug-induced liver injury (DILI) as its main cause, or alcoholic liver disease (ALD). Although programs carried out by authorities are focused on improving dietary habits and lifestyle, the long-term compliance of the patient makes them difficult to follow. Thus, the supplementation with certain substances may represent a more easy-to-follow approach for patients. In this context, the consumption of polyphenol-rich food represents an attractive alternative as these compounds have been characterized to be effective in ameliorating liver pathologies. Despite of their structural diversity, certain similar characteristics allow to classify polyphenols in 5 groups: stilbenes, flavonoids, phenolic acids, lignans and curcuminoids. Herein, we have identified the most relevant compounds in each group and characterized their main sources. By this, authorities should encourage the consumption of polyphenol-rich products, as most of them are available in quotidian life, which might reduce the socioeconomical burden of liver diseases.

The effect of egg and its derivatives on vascular function: A systematic review of interventional studies

BACKGROUND & AIMS

Cardiovascular diseases (CVDs) are considered as a major cause of health loss for all regions of the world. Atherosclerosis is one of the most important underlying causes of CVDs. Vascular dysfunction is the primary marker of atherosclerosis. Various studies have investigated the effect of egg intake on CVDs. This study aimed to determine the effect of egg and its derivatives consumption on vascular function.

METHODS

Using a comprehensive search strategy, the searching was conducted on PubMed, Scopus and Google Scholar search engines resources (from inception up to Feb 2020). Intended exposure and outcome were egg or its derivatives intake, and vascular function measuring methods, respectively.

RESULTS

A total of 35 papers were found through search databases. Finally, seven trials were included, which were published between 2005 and 2018. Results showed that acute and chronic consumption of whole eggs did not have a significant adverse effect on flow-mediated dilatation (FMD). Also, lutein-enriched egg yolk and egg ovalbumin-derived protein hydrolysate did not have significant positive effects on FMD and pulse wave velocity (PWV), respectively. However, one month egg-yolk-derived phospholipid (PL) preparation intervention increased FMD by 3.4% (p < 0.05), and replacing a portion of a glucose challenge with whole eggs or egg whites improved postprandial FMD (p < 0.05).

CONCLUSIONS

We concluded that consumption of whole egg, despite being rich in cholesterol, has no adverse effect on vascular function, and even some of egg derivatives may improve vascular function. Further research is needed to justify the potential effects of egg or its derivatives on vascular function.

The influence of different concentrations of flavanol chocolate bars under acute supplement conditions on exercise and performance

OBJECTIVE

The purpose of this study was to assess the effects and acute dosage of different flavanol concentrations in a dark chocolate bar on physiological parameters during steady state (SS) and incremental exercise.

METHODS

In a double-blind, randomised, crossover study, 15 healthy participants with a mean ± SD age of 30 ± 7 years; stature 176.8 ± 8.6 cm and body mass 80.3 ± 8.4 kg supplemented with high flavanol (HF) (1060 mg), moderate flavanol (MF) (746 mg), low flavanol (LF) (406 mg), or a control (CON) (88 mg) chocolate bar (~ 34 g), 2 h prior to 40 min of SS cycling (80% gas-exchange threshold) followed by an incremental test to volitional fatigue. During the SS cycle oxygen consumption ([Formula: see text]), respiratory exchange ratio (RER) and heart rate (HR) were continuously monitored. Plasma samples were collected prior to commencing exercise to determine nitrate (NO₃^-) and nitrite (NO₂^-) levels under each condition.

RESULTS

There was no observed effect between flavanol concentrations on [Formula: see text], RER, and HR during SS cycling (P > 0.05). [Formula: see text], peak power, HR peak, and RER peak also did not significantly differ between conditions (P > 0.05). There was a small trend for higher plasma NO₂^- levels following higher flavanol concentration; however, this did not reach statistical significance (P > 0.05).

CONCLUSION

Acute supplementation with cocoa of differing flavanol concentrations does not appear to have any effect on exercise and performance. It is plausible that longer flavanol supplementation periods might have greater accumulative effects and thus may potentially elicit a larger effect.

The effect of garlic on vascular function: A systematic review of randomized clinical trials

BACKGROUNDS AND AIMS

Atherosclerosis and its associated cardiovascular disease (CVD) represent a major global health problem worldwide and vascular dysfunction is important in its pathogenesis. Clinical trials investigating the effect of garlic on vascular function measured by several non-invasive methods and their results are inconsistent. This study aimed to summarize the current evidence regarding the effectiveness of garlic as one of the world's most ancient medicines on measures of vascular reactivity and/or stiffness in adults.

METHODS

All published RCTs in English were systematically searched on PubMed, Scopus and Google Scholar search engines up to Oct 2019. The exposure and outcome variable of interest were garlic and vascular function measurements. Ten trials which met inclusion criteria were included in this study.

RESULTS

A total of 45 studies were found through search databases. After excluding duplicates, the 25 remaining studies were screened by title and abstract which 15 of them excluded. Finally, ten trials were included in this review study, which were published between 2004 and 2018.

CONCLUSIONS

Findings were inconsistent. However, garlic has the potential to improve vascular function, particularly in subjects with cardiovascular risk factors. Additional human studies on garlic and its constituents should consider the population and the specific type of garlic preparation.

The Effect of a Single Dose of Dark Chocolate on Cardiovascular Parameters and Their Reactivity to Mental Stress

Objective: This study investigated the effect of a single administration of dark or milk chocolate on blood pressure (BP), heart rate (HR), and double product (DP) in young healthy women at rest and during acute mental stress.Method: Measurements consisted of anthropometry, BP, and HR. Mean arterial BP (MAP) and DP were computed. The relative reactivity of individual variables was quantified as to their percentage change during the rest or test of mental arithmetic (MA) with respect to the respective baseline value. All subjects underwent two tests of MA-one before chocolate administration and the second one 2 hours after chocolate (1 mg/g of body weight) ingestion.Results: Two hours after ingestion at rest, dark chocolate administration resulted in a significant increase in relative values of systolic BP and DP by 5.1% ± 1.4% and 13.7% ± 3.2%, respectively, compared to the responses in the milk chocolate group (-2.4% ± 1.6% and 0.6% ± 3.4%, respectively, p < 0.04 for both comparisons) without changes in diastolic BP, HR, and MAP. During MA-induced acute stress, the relative magnitude of the reactivity of diastolic BP, HR, MAP, and DP decreased by about 10, 16, 8, and 23 percentage points, respectively, 2 hours after ingestion of dark chocolate compared to the relative reactivity determined before dark chocolate ingestion. Milk chocolate failed to affect any of the above-mentioned parameters at rest or during stress.Conclusions: The single oral intake of 85% dark chocolate increased relative values of systolic BP and DP at rest but buffered the reactivity of diastolic BP, HR, MAP, and DP during mental stress, which was not found after ingestion of milk chocolate. Thus, dark chocolate might have a beneficial effect during acute stress due to its ability to buffer cardiovascular reactivity in young healthy women.

Flavanols protect the yeast Saccharomyces cerevisiae against heating and freezing/thawing injury

AIMS

The aim of the study was to check whether two flavanols ((-)-epigallocatechin gallate and (+)-catechin) can ameliorate oxidative stress (OS) accompanying and contributing to the lethal effects of heating (50°C) and freezing-thawing on the yeast Saccharomyces cerevisiae.

METHODS AND RESULTS

The flavanols studied increased yeast survival during heating and freezing-thawing, estimated by the colony forming assay. They improved also such indices of OS as increased production of reactive oxygen species, decrease of total antioxidant activity of yeast cell extracts and increase in the level of protein carbonyls.

CONCLUSIONS

Amelioration of OS by flavanols increases the survival of the yeast subjected to high temperature and freezing-thawing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Flavanols may be considered as means of enhancing yeast survival under extreme temperature conditions and probably in other conditions involving OS.