Background/Objectives: Microgreens are rich in nutrients and phytochemicals that can support healthy aging, including attenuation of cardiovascular disease risk. The nutrient and phytochemical contents of red beet (i.e., bull’s blood’ beet, Beta vulgaris) and red cabbage (Brassica oleracea var capitate) microgreens, as well as existing preclinical evidence suggest their cardioprotective effects, but the feasibility, gastrointestinal tolerability, and human health effects of daily microgreen consumption are unknown. This study aimed to evaluate the feasibility and gastrointestinal tolerability of 2 weeks of daily microgreen consumption in healthy middle-aged/older (MA/O) adults. A secondary aim was to characterize potential health effects. Methods: Healthy MA/O adults (initial n = 26) were randomized to consume either 2 cups of ‘bull’s blood’ beet or red cabbage microgreens daily for 2 weeks in a crossover design, with each treatment period separated by 2 weeks. Feasibility was determined through participant retention and intervention compliance (i.e., total doses consumed divided by 14 days), while gastrointestinal tolerability was determined by a gastrointestinal health questionnaire and bowel movement log. Impacts of microgreen consumption on brachial and aortic hemodynamic parameters, and gut microbiota composition were evaluated. Results: Daily consumption for 2 weeks of ‘bull’s blood’ beet and red cabbage microgreens was found to be feasible as indicated by high participant retention (final n = 24) and overall treatment compliance of 95.6%. Gastrointestinal symptom severity was not impacted overall, though an improvement in gastrointestinal inflammation-associated symptom severity scores following the red cabbage microgreen intervention (p = 0.047) was observed. There were no changes in bowel movement quality, hemodynamic parameters, or on alpha or beta diversity of the gut microbiota. Conclusions: Daily consumption of ‘bull’s blood’ beet and red cabbage microgreens is feasible and tolerable in healthy MA/O adults. Future studies designed to evaluate their health impacts are needed.
Estrogen-deficient postmenopausal women have oxidative stress-mediated suppression of endothelial function that is exacerbated by high blood pressure. Previous research suggests blueberries may improve endothelial function through reductions in oxidative stress, while also exerting other cardiovascular benefits. The objective of this study was to examine the efficacy of blueberries to improve endothelial function and blood pressure in postmenopausal women with above-normal blood pressure, and to identify potential mechanisms for improvements in endothelial function. A randomized, double-blind, placebo-controlled, parallel-arm clinical trial was performed, where postmenopausal women aged 45-65 years with elevated blood pressure or stage 1-hypertension (total n = 43, endothelial function n = 32) consumed 22 g day-1 of freeze-dried highbush blueberry powder or placebo powder for 12 weeks. Endothelial function was assessed at baseline and 12 weeks through ultrasound measurement of brachial artery flow-mediated dilation (FMD) normalized to shear rate area under the curve (FMD/SRAUC) before and after intravenous infusion of a supraphysiologic dose of ascorbic acid to evaluate whether FMD improvements were mediated by reduced oxidative stress. Hemodynamics, arterial stiffness, cardiometabolic blood biomarkers, and plasma (poly)phenol metabolites were assessed at baseline and 4, 8, and 12 weeks, and venous endothelial cell protein expression was assessed at baseline and 12 weeks. Absolute FMD/SRAUC was 96% higher following blueberry consumption compared to baseline (p < 0.05) but unchanged in the placebo group (p > 0.05), and changes from baseline to 12 weeks were greater in the blueberry group than placebo (+1.09 × 10-4 ± 4.12 × 10-5vs. +3.82 × 10-6 ± 1.59 × 10-5, p < 0.03, respectively). The FMD/SRAUC response to ascorbic acid infusion was lower (p < 0.05) at 12 weeks compared to baseline in the blueberry group with no change in the placebo group (p > 0.05). The sum of plasma (poly)phenol metabolites increased at 4, 8, and 12 weeks in the blueberry group compared to baseline, and were higher than the placebo group (all p < 0.05). Increases in several plasma flavonoid and microbial metabolites were also noted. No major differences were found for blood pressure, arterial stiffness, blood biomarkers, or endothelial cell protein expression following blueberry consumption. These findings suggest daily consumption of freeze-dried blueberry powder for 12 weeks improves endothelial function through reduced oxidative stress in postmenopausal women with above-normal blood pressure. The clinical trial registry number is NCT03370991 (https://clinicaltrials.gov).
Research suggests blueberries and their (poly)phenols may improve endothelial dysfunction, a major risk factor for cardiovascular disease (CVD). The objective of this study was to investigate the impact of consuming 22 g/day for 12 weeks of freeze-dried highbush blueberry powder on endothelial function and other measures of cardiovascular health, oxidative stress, and circulating (poly)phenol metabolites in postmenopausal women with above-normal blood pressure. We performed a randomized, double-blind, placebo-controlled, parallel-arm trial in estrogen-deficient postmenopausal women aged 45–65 years with elevated blood pressure or stage 1-HTN. Endothelial function was assessed as brachial artery flow-mediated dilation (FMD) and normalized to individual shear rate area under the curve (FMD/SRAUC) to control for inter-individual variability in reactive hyperemia-induced shear stress. To assess whether improvements in FMD were mediated by reduced oxidative stress, FMD was assessed before and after intravenous infusion of a supra-physiologic dose of ascorbic acid. Blood pressure, arterial stiffness, and plasma (poly)phenol metabolites were also assessed. A total of 43 women completed the trial (n = 32 for endothelial function). Compliance in the Blueberry and Placebo groups were 93% and 91%, respectively. Mean total plasma (poly)phenol metabolite concentrations were increased at 4 (250,053 nmol/L, P < 0.05) and 8 (303,053 nmol/L, P < 0.05) weeks in the Blueberry group compared to baseline (125,798 nmol/L) with a strong trend at 12 weeks (227,971 nmol/L, P < 0.05), and no changes in Placebo. Blood pressure and arterial stiffness were unchanged with both treatments. At 12 weeks, FMD/SRAUC was increased by 96% from baseline (P < 0.05) in the Blueberry group but unchanged in Placebo, and changes in FMD/SRAUC from baseline to 12 weeks were higher (P < 0.05) than Placebo. The response in FMD/SRAUC to ascorbic acid infusion was lower (P < 0.05) at 12 weeks compared to baseline in the Blueberry group but not Placebo. These findings suggest blueberries improve endothelial function, and is mediated, in part, by reduced oxidative stress in postmenopausal women with above-normal blood pressure, a high-risk population for developing CVD. US Highbush Blueberry Council and USDA National Institute of Food and Agriculture.
ABSTRACT Background Microgreens are the young leafy greens of many vegetables, herbs, grains, and flowers with potential to promote human health and sustainably diversify the global food system. For successful further integration into the global food system and evaluation of their health impacts, it is critical to elucidate and optimize their nutritional quality. Objectives We aimed to comprehensively evaluate the metabolite and mineral contents of 6 microgreen species, and the influence of maturity on their contents. Methods Plant species evaluated were from the Brassicaceae (arugula, broccoli, and red cabbage), Amaranthaceae (red beet and red amaranth), and Fabaceae (pea) plant families. Nontargeted metabolomics and ionomics analyses were performed to examine the metabolites and minerals, respectively, in each microgreen species and its mature counterpart. Results Nontargeted metabolomics analysis detected 3321 compounds, 1263 of which were annotated and included nutrients and bioactive compounds. Ionomics analysis detected and quantified 26 minerals including macrominerals, trace minerals, ultratrace minerals, and other metals. Principal component analysis indicated that microgreens have distinct metabolite and mineral profiles compared with one another and with their mature counterparts. Several compounds were higher (P < 0.05; fold change ≥2) in microgreens compared with their mature counterparts, whereas some were not different or lower. In many cases, compounds that were higher in microgreens compared with the mature counterpart were also unique to that microgreen species. Conclusions These data provide evidence for the nutritional quality of microgreens, and can inform future research and development aimed at characterizing and optimizing microgreen nutritional quality and health impacts.
Microgreens are an emerging functional food crop with promise for sustainably diversifying global food systems, facilitating adaptations to urbanization and global climate change, and promoting human health. Previous work suggests microgreens have high nutritional quality, low environmental impacts, and broad consumer acceptance. For better reception into the global food system and increased per capita consumption, research is needed to elucidate consumer acceptance of various microgreens species, including factors contributing to their acceptance or lack thereof. Using a consumer panel (n = 99), this study evaluated consumer sensory perception and acceptability of six microgreens species (arugula, broccoli, bull's blood beet, red cabbage, red garnet amaranth, and tendril pea), and potential drivers and barriers to consumer acceptance. All microgreens species received high mean liking scores for acceptability by consumers (means ranged from highly acceptable to slightly acceptable), with more distinct differences across microgreens species for flavor and overall acceptability, which appeared to be driven by specific sensory properties. Data from principal component analysis demonstrated that high acceptability scores were associated with higher intent to purchase microgreens and negatively associated with food neophobia. Participants indicated that factors such as knowledge and familiarity of microgreens, cost, access/availability, freshness/shelf life, among other factors, influence their intention to purchase microgreens. These findings suggest that further integration of microgreens into the global food system will be met with high consumer acceptability, but needs to be aligned with enhanced consumer education regarding microgreens, as well as considerations of cost, availability/access, and freshness/shelf life. PRACTICAL APPLICATION: Researchers investigated consumer sensory perception and acceptability of six microgreens species (arugula, broccoli, bull's blood beet, red cabbage, red garnet amaranth, and tendril pea), and potential drivers and barriers to consumer acceptance. All microgreens tested had high consumer acceptability, but certain factors such as sensory perception and food neophobia impacted their acceptability. Additionally, participants indicated that factors such as knowledge, access and availability, cost, freshness, and shelf life may impact the purchasing of microgreens and thus are important factors to consider for further integration of this emerging functional food crop into the global food system.
Aging is the primary risk factor for cardiovascular disease (CVD) largely due to vascular endothelial dysfunction, an initiating step in the development of atherosclerosis. The gut microbiota has emerged as an important regulator of cardiovascular health. Aronia berries are rich in polyphenols such as anthocyanins, proanthocyanidins, and phenolic acids. These compounds, and metabolites resulting from gut microbial and phase II metabolism, have been shown to improve endothelial function. The primary objective of this study is to assess the dose-dependent efficacy of an aronia berry full spectrum dietary supplement to improve vascular endothelial function in middle-aged/older men and postmenopausal women. A secondary goal is to determine whether aronia full spectrum modulation of the gut microbiota is associated with improvements in vascular endothelial function. Healthy men and postmenopausal women (n = 28) aged 45–75 years are being recruited for this randomized, double-blind, placebo-controlled, crossover trial. In random order, participants take a placebo, 500 mg aronia full spectrum, or 1000 mg aronia full spectrum daily for a 6-week period. Each treatment period is separated by a 6-week washout period. The primary outcome is reactive hyperemia index (RHI), a validated measure of vascular endothelial function assessed using peripheral arterial tonometry. Secondary outcome measures include analysis of the gut microbiota in stool samples, hemodynamic parameters including blood pressure and augmentation index, arterial stiffness, and blood biomarkers of cardiovascular and metabolic health including blood lipids, hemoglobin a1c, oxidized LDL, and adhesion molecules. Other outcome measures will include plasma, fecal, and urine polyphenol metabolites. Gut microbial populations will be statistically compared with RHI. To date, a total of 22 individuals (11 men/11 women) have been enrolled in the trial and randomized to their intervention order. Of these, 3 have completed the study, 1 was lost to follow-up, and 18 are currently enrolled. We hypothesize that this aronia berry dietary supplement will dose-dependently improve vascular endothelial function in healthy middle-aged/older adults, and that improvements will be linked to modulation of the gut microbiota. Naturex.
Dietary inorganic nitrate from foods such as red beetroot juice (RBJ) can contribute to nitric oxide (NO) bioavailability through the enterosalivary nitrate-nitrite-NO pathway. A critical step in this pathway is the reduction of nitrate to nitrite by oral bacteria. We investigated the effects of inorganic nitrate supplementation, as RBJ or placebo + potassium nitrate (PBO+NIT), on the oral microbiota, and its relationship with saliva and plasma NO metabolites and vascular endothelial function. In a randomized, double-blind, placebo-controlled trial, we measured the abundance of oral nitrate-reducing bacteria in saliva samples from 15 middle-aged/older adults with overweight and obesity using 16 rRNA sequencing. We also assessed the relationship of oral nitrate-reducing bacteria with the physiological responses to acute (4 hours) and chronic (4 weeks) RBJ, PBO+NIT, nitrate-free RBJ, and placebo supplementation via measurement of saliva and plasma nitrate/nitrite (NOx), plasma nitrite levels, and reactive hyperemia index (RHI). A significant decrease in the alpha diversity metric, Pileou's Evenness, was detected after chronic consumption of PBO+NIT (0.69 ± 0.05 at week 0 vs. 0.65 ± 0.05 at week 4; P < 0.05), while there was a trend for a decline following RBJ consumption (0.69 ± 0.05 at week 0 vs. 0.65 ± 0.05 at week 4; P = 0.08). No significant differences in abundance of nitrate-reducing bacteria were observed after chronic supplementation, although abundance of the species Neisseria subflava was trending toward an increase in the RBJ group (10.8% at week 0 vs. 12.2% at week 4; P = 0.07). Plasma and saliva NOx increased from baseline and remained elevated for the 4-hour testing period after acute and chronic RBJ and PBO+NIT supplementation (all P < 0.05), while plasma nitrite only peaked at 2 hours in the RBJ group after acute supplementation and was significantly higher than PBO+NIT group (P < 0.01). RHI change from baseline to 4 hours was positively correlated with total abundance of nitrate-reducing species after chronic RBJ supplementation (r = 0.5; P = 0.05). Acute and chronic RBJ and PBO+NIT supplementation increases NO metabolites and may alter the oral microbiota to favorably affect vascular endothelial function in middle-aged/older adults with overweight and obesity. NIFA, USDA.
Colorado Agricultural Experiment Station, NIFA, USDA.
The gut microbiota is emerging as an important regulator of cardiovascular health. Indeed, gut dysbiosis is increasingly being linked to the development of cardiovascular disease (CVD). Aging and obesity are associated with the development of CVD largely due to the development of vascular dysfunction, namely endothelial dysfunction and arterial stiffness. The objective of this study was to examine the relationship between the gut microbiota, blood pressure, and vascular function in aging overweight and obese individuals. This cross-sectional study included fifteen overweight and obese (mean body mass index, BMI: 29.5; range: 25.8–37.0) middle-aged/older men and postmenopausal women (mean age: 53; range: 42–64 years). Blood pressure, arterial stiffness (augmentation index, AIx, and aortic pulse wave velocity, aPWV), and endothelial function (reactive hyperemia index, RHI) were assessed. Stool samples were collected for gut microbiota analysis using 16S ribosomal RNA sequencing. Principal coordinates analysis and Pearson’s correlations were performed to evaluate the relationship between the gut microbiota and measures of vascular function and blood pressure. Global gut microbiota phenotypes clustered most strongly by aPWV (groups separated by median value) as visualized by Non-Metric Dimensional Scaling plot of Bray-Curtis Distances (stress = 0.09; P = 0.07). Several bacterial taxa correlated with vascular parameters. For example, Bifidobacterium longum (r = 0.80, P < 0.001) and Akkermansia muciniphila (r = 0.56, P = 0.047) were positively correlated with RHI. Bifdobacterium bifidum (r = −0.61, P = 0.02) and Oxalobacter formigenes (r = −0.62, P = 0.02) were negatively correlated with systolic blood pressure. Interestingly, there was no significant clustering by BMI groupings (overweight vs. obese) or correlations between BMI and specific taxa. These preliminary data suggest that the gut microbiota is linked to vascular dysfunction and increased blood pressure in aging overweight and obese individuals independent of BMI. Further data collection and analysis are currently underway to explore these relationships in a larger human cohort, and to explore underlying mechanisms through transferring of vascular phenotypes in humans to germ-free mice through microbiota transplantation. NIFA, USDA.
Background: High-fat meal (HFM) consumption may induce transient postprandial atherogenic responses, including impairment of vascular endothelial function, in individuals with overweight/obesity. Red beetroot juice (RBJ) may modulate endothelial function and other measures of cardiometabolic health. Objective: This study investigated the impact of acute and chronic RBJ consumption, including nitrate-dependent and -independent effects, on postprandial endothelial function and other cardiometabolic responses to a HFM. Methods: Fifteen men and postmenopausal women with overweight/obesity were enrolled in this randomized, double-blind, placebo-controlled, 4-period, crossover clinical trial. Following an overnight fast, participants underwent baseline assessment of endothelial function (reactive hyperemia index; RHI) and hemodynamics, and biological sample collection. In random order, participants consumed 70 mL (acute visit) of: 1) RBJ, 2) nitrate-free RBJ (NF-RBJ), 3) placebo + nitrate (PBO + NIT), or 4) placebo (PBO), followed by a HFM. RHI was remeasured 4 h post-HFM, and hemodynamic assessment and biological sample collection were performed 1, 2, and 4 h post-HFM consumption. Participants consumed treatments daily for 4 wk (chronic visit), and assessments were repeated before/after the HFM (without consuming treatments). Results: HFM consumption did not induce significant impairment of postprandial RHI. No significant differences in RHI were detected across treatment groups following acute or chronic exposure, despite increases in circulating nitrate/nitrite (NOx) concentrations in the RBJ and PBO + NIT groups compared with PBO and NF-RBJ (P < 0.0001 for all time points at the acute visit; P < 0.05 for all time points at the chronic visit). Although the HFM led to significant alterations in several secondary outcomes, there were no consistent treatment effects on postprandial cardiometabolic responses. Conclusions: HFM consumption did not impair postprandial endothelial function in this population, and RBJ exposure did not alter postprandial endothelial function or other outcomes despite increasing NOx concentrations. This trial is registered at clinicaltrials.gov as NCT02949115.
Chloe Robert,1 Charline Buisson,2 Leslie Couëdelo,3 Emmanuelle Meugnier,2 Carole Knibbe,4 Emmanuelle Loizon,2 Laurence Fonseca,3 Fabienne Laugerette,2 Carole Vaysse,3 and Marie-Caroline Michalski2 1ITERG, CarMeN Laboratory, INRAE, INSERM, Université Claude Bernard Lyon 1, INSA-Lyon; 2CarMeN laboratory, INRAE, INSERM, Université Claude Bernard Lyon 1, INSA-Lyon; 3ITERG; and 4Inria “Beagle” team, CarMeN laboratory, INRAE, INSERM, Université Claude Bernard Lyon 1, INSA-Lyon