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The Impact of COVID-19 Stay-At-Home Orders on Health Behaviors in Adults.
Flanagan, EW, Beyl, RA, Fearnbach, SN, Altazan, AD, Martin, CK, Redman, LM
Obesity (Silver Spring, Md.). 2021;29(2):438-445
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In response to the global outbreak of COVID-19, a wave of quarantine and stay-at-home mandates were issued to attenuate the rapid worldwide spread. The aim of this study was to quantify changes in habitual dietary behaviours, physical activity, sleep, sedentary behaviours, and mental health before and during the initial peak of the COVID-19 pandemic. This study is based on an anonymous survey via paid advertisements on the social media platform Facebook. A total of 7,753 completed the first COVID-19 question and were thus included in the analysis. Results indicate that: - declines in healthful eating behaviours were coincident with reductions in physical activity. These negative behaviours were characteristic of individuals reporting weight gain in response to the pandemic outbreak. - anxiety scores nearly doubled in response to the pandemic and 20% of the sample reported that symptoms were severe enough to interfere with daily routines. - home confinement led to shifts in daily work and household responsibilities which resulted in mental health declines alongside some positive and many negative changes to health behaviours. Authors conclude that with increased cases of weight gain and significant declines to mental health, COVID-19 may impact clinical practice for years to come.
Abstract
OBJECTIVE Stay-at-home orders in response to the coronavirus disease 2019 (COVID-19) pandemic have forced abrupt changes to daily routines. This study assessed lifestyle changes across different BMI classifications in response to the global pandemic. METHODS The online survey targeting adults was distributed in April 2020 and collected information on dietary behaviors, physical activity, and mental health. All questions were presented as "before" and "since" the COVID-19 pandemic. RESULTS In total, 7,753 participants were included; 32.2% of the sample were individuals with normal weight, 32.1% had overweight, and 34.0% had obesity. During the pandemic, overall scores for healthy eating increased (P < 0.001), owing to less eating out and increased cooking (P < 0.001). Sedentary leisure behaviors increased, while time spent in physical activity (absolute time and intensity adjusted) declined (P < 0.001). Anxiety scores increased 8.78 ± 0.21 during the pandemic, and the magnitude of increase was significantly greater in people with obesity (P ≤ 0.01). Weight gain was reported in 27.5% of the total sample compared with 33.4% in participants with obesity. CONCLUSIONS The COVID-19 pandemic has produced significant health effects, well beyond the virus itself. Government mandates together with fear of contracting the virus have significantly impacted lifestyle behaviors alongside declines in mental health. These deleterious impacts have disproportionally affected individuals with obesity.
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A Systematic Review of the Association Between Vegan Diets and Risk of Cardiovascular Disease.
Kaiser, J, van Daalen, KR, Thayyil, A, Cocco, MTARR, Caputo, D, Oliver-Williams, C
The Journal of nutrition. 2021;151(6):1539-1552
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Plant-based diets have increased in popularity due to concerns for the environment and animal welfare and due to perceived health benefits. The aim of this study was to assess the association between vegan diets and risks of primary, intermediate, and recurrent cardiovascular disease (CVD). This study is a systemic review of 7 epidemiological studies comprising over 73,000 participants, of whom at least 7661 were vegans. Results indicate that there was no significant evidence of an association between adherence to a vegan diet and risks of primary CVD or a coronary heart disease event. Authors conclude that further experimental evidence and research in large diverse cohorts is required in order to better understand the clinical relevance and public health implications of the vegan diet.
Abstract
BACKGROUND Plant-based diets are gaining attention globally due to their environmental benefits and perceived health-protective role. A vegan diet may have cardiovascular benefits; however, evidence remains conflicting and insufficiently assessed. OBJECTIVES We evaluated the utility of the vegan diet in cardiovascular disease (CVD) prevention. METHODS We conducted a systematic review of studies evaluating the association between vegan diets and cardiovascular outcomes. We searched 5 databases (Ovid MEDLINE, EMBASE, Web of Science, Scopus, and OpenGrey) through 31 October 2020. Four investigators independently screened the full texts for inclusion, assessed quality, and extracted data from published reports. RESULTS Out of the 5729 identified records, 7 were included, comprising over 73,000 participants, of whom at least 7661 were vegans. Three studies, with at least 73,426 individuals (including at least 7380 vegans), examined risks of primary cardiovascular events (total CVD, coronary heart disease, acute myocardial infarction, total stroke, hemorrhagic stroke, and ischemic stroke) in individuals who followed a vegan diet compared to those who did not. None of the studies reported a significantly increased or decreased risk of any cardiovascular outcome. One study suggested that vegans were at greater risk of ischemic stroke compared to individuals who consumed animal products (HR, 1.54; 95% CI, 0.95-2.48). Yet in another study, vegans showed lower common carotid artery intima-media thickness (0.56 ± 0.1 mm vs. 0.74 ± 0.1 mm in controls; P < 0.001), and in 3 studies of recurrent CVD events, vegans had 0-52% lower rates. Furthermore, endothelial function did not differ between vegans and nonvegans. Using the Grading of Recommendations Assessment, Development and Evaluation approach, evidence was deemed to be of low to very low strength/quality. CONCLUSIONS Among the Western populations studied, evidence weakly demonstrates associations between vegan diets and risk of CVDs, with the direction of associations varying with the specific CVD outcome tested. However, more high-quality research on this topic is needed. This study was registered at PROSPERO as CRD42019146835.
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Association of Major Dietary Protein Sources With All-Cause and Cause-Specific Mortality: Prospective Cohort Study.
Sun, Y, Liu, B, Snetselaar, LG, Wallace, RB, Shadyab, AH, Kroenke, CH, Haring, B, Howard, BV, Shikany, JM, Valdiviezo, C, et al
Journal of the American Heart Association. 2021;10(5):e015553
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Dietary recommendations for human health focusing on total protein intake without considering specific protein sources may be simplistic and insufficient. The aim of this study was to investigate whether different dietary protein sources would be differentially associated with mortality risk. The study is based on data from a large prospective cohort study with up to 18-years of follow-up to investigate the risks of all-cause and cause-specific mortality in relation to animal and plant protein intake, and major sources of dietary protein. Results indicate that intake of plant protein and substitution of animal protein with plant protein, were associated with lower risk of all-cause, cardiovascular disease, and dementia mortality. Furthermore, substitution of red meat, eggs, dairy products, or legumes with nuts was associated with lower risk of all-cause mortality. Authors conclude that their findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.
Abstract
Background Dietary recommendations regarding protein intake have been focused on the amount of protein. However, such recommendations without considering specific protein sources may be simplistic and insufficient. Methods and Results We included 102 521 postmenopausal women enrolled in the Women's Health Initiative between 1993 and 1998, and followed them through February 2017. During 1 876 205 person-years of follow-up, 25 976 deaths occurred. Comparing the highest with the lowest quintile, plant protein intake was inversely associated with all-cause mortality (hazard ratio [HR], 0.91 [0.86, 0.96]), cardiovascular disease mortality (HR, 0.88 [0.79, 0.97]), and dementia mortality (HR, 0.79 [0.67, 0.94]). Among major protein sources, comparing the highest with the lowest quintile of consumption, processed red meat (HR, 1.06 [1.01, 1.10]) or eggs (HR, 1.14 [1.10, 1.19]) was associated with higher risk of all-cause mortality. Unprocessed red meat (HR, 1.12 [1.02, 1.23]), eggs (HR, 1.24 [1.14, 1.34]), or dairy products (HR, 1.11 [1.02, 1.22]) was associated with higher risk of cardiovascular disease mortality. Egg consumption was associated with higher risk of cancer mortality (HR, 1.10 [1.02, 1.19]). Processed red meat consumption was associated with higher risk of dementia mortality (HR, 1.20 [1.05, 1.32]), while consumption of poultry (HR, 0.85 [0.75, 0.97]) or eggs (HR, 0.86 [0.75, 0.98]) was associated with lower risk of dementia mortality. In substitution analysis, substituting of animal protein with plant protein was associated with a lower risk of all-cause mortality, cardiovascular disease mortality, and dementia mortality, and substitution of total red meat, eggs, or dairy products with nuts was associated with a lower risk of all-cause mortality. Conclusions Different dietary protein sources have varying associations with all-cause mortality, cardiovascular disease mortality, and dementia mortality. Our findings support the need for consideration of protein sources in future dietary guidelines.
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Effectiveness of Mindfulness Meditation vs Headache Education for Adults With Migraine: A Randomized Clinical Trial.
Wells, RE, O'Connell, N, Pierce, CR, Estave, P, Penzien, DB, Loder, E, Zeidan, F, Houle, TT
JAMA internal medicine. 2021;181(3):317-328
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Mindfulness-based stress reduction (MBSR), a standardized mind-body treatment that teaches momentary awareness with decreased sensory percept judgment, is associated with improvements in many chronic pain conditions. Mindfulness may be particularly helpful for migraine, as it diminishes affective responses to stress, the most common migraine trigger. This study is a double-blinded, randomized clinical trial of MBSR vs headache education for adults with migraine. The study enrolled 96 participants out of which 89 participants attended at least 1 class and completed at least 1 headache log (MBSR, 45; headache education, 44) across 7 cohorts. Participants were randomly assigned to one of the two arms. Results indicate that participants in both groups demonstrated a reduction of migraine days per month from baseline at 12 weeks. Furthermore, both groups sustained reductions in frequency of migraine and headache without group differences. Compared with headache education, MBSR participants had improvements in headache-related disability, quality of life, depression scores, self-efficacy, pain catastrophizing, and decreased experimentally induced pain intensity and unpleasantness out to 36 weeks. Authors conclude that mindfulness may help treat the total burden of migraine. However, a larger, more definitive study is needed to understand the impact of mindfulness on migraine.
Abstract
Importance: Migraine is the second leading cause of disability worldwide. Most patients with migraine discontinue medications due to inefficacy or adverse effects. Mindfulness-based stress reduction (MBSR) may provide benefit. Objective: To determine if MBSR improves migraine outcomes and affective/cognitive processes compared with headache education. Design, Setting, and Participants: This randomized clinical trial of MBSR vs headache education included 89 adults who experienced between 4 and 20 migraine days per month. There was blinding of participants (to active vs comparator group assignments) and principal investigators/data analysts (to group assignment). Interventions: Participants underwent MBSR (standardized training in mindfulness/yoga) or headache education (migraine information) delivered in groups that met for 2 hours each week for 8 weeks. Main Outcomes and Measures: The primary outcome was change in migraine day frequency (baseline to 12 weeks). Secondary outcomes were changes in disability, quality of life, self-efficacy, pain catastrophizing, depression scores, and experimentally induced pain intensity and unpleasantness (baseline to 12, 24, and 36 weeks). Results: Most participants were female (n = 82, 92%), with a mean (SD) age of 43.9 (13.0) years, and had a mean (SD) of 7.3 (2.7) migraine days per month and high disability (Headache Impact Test-6: 63.5 [5.7]), attended class (median attendance, 7 of 8 classes), and followed up through 36 weeks (33 of 45 [73%] of the MBSR group and 32 of 44 [73%] of the headache education group). Participants in both groups had fewer migraine days at 12 weeks (MBSR: -1.6 migraine days per month; 95% CI, -0.7 to -2.5; headache education: -2.0 migraine days per month; 95% CI, -1.1 to -2.9), without group differences (P = .50). Compared with those who participated in headache education, those who participated in MBSR had improvements from baseline at all follow-up time points (reported in terms of point estimates of effect differences between groups) on measures of disability (5.92; 95% CI, 2.8-9.0; P < .001), quality of life (5.1; 95% CI, 1.2-8.9; P = .01), self-efficacy (8.2; 95% CI, 0.3-16.1; P = .04), pain catastrophizing (5.8; 95% CI, 2.9-8.8; P < .001), depression scores (1.6; 95% CI, 0.4-2.7; P = .008), and decreased experimentally induced pain intensity and unpleasantness (MBSR group: 36.3% [95% CI, 12.3% to 60.3%] decrease in intensity and 30.4% [95% CI, 9.9% to 49.4%] decrease in unpleasantness; headache education group: 13.5% [95% CI, -9.9% to 36.8%] increase in intensity and an 11.2% [95% CI, -8.9% to 31.2%] increase in unpleasantness; P = .004 for intensity and .005 for unpleasantness, at 36 weeks). One reported adverse event was deemed unrelated to study protocol. Conclusions and Relevance: Mindfulness-based stress reduction did not improve migraine frequency more than headache education, as both groups had similar decreases; however, MBSR improved disability, quality of life, self-efficacy, pain catastrophizing, and depression out to 36 weeks, with decreased experimentally induced pain suggesting a potential shift in pain appraisal. In conclusion, MBSR may help treat total migraine burden, but a larger, more definitive study is needed to further investigate these results. Trial Registration: ClinicalTrials.gov Identifier: NCT02695498.
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Lipids activate skeletal muscle mitochondrial fission and quality control networks to induce insulin resistance in humans.
Axelrod, CL, Fealy, CE, Erickson, ML, Davuluri, G, Fujioka, H, Dantas, WS, Huang, E, Pergola, K, Mey, JT, King, WT, et al
Metabolism: clinical and experimental. 2021;121:154803
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Insulin resistance is a key pathophysiological mechanism in the development and progression of type 2 diabetes. Abnormalities in lipid metabolism and ectopic lipid accumulation are known to directly contribute to the onset of insulin resistance. Authors hypothesised that lipid infusion would increase dynamin related protein 1 [a type of protein]-mediated mitochondrial fission in skeletal muscle independent of function and content, consequently reducing peripheral insulin sensitivity. The study included sedentary but otherwise healthy adults who were prospectively randomized to receive either lipid or saline infusion to isolate the direct contribution of fatty acids to skeletal muscle mitochondrial dynamics. Results show that mitochondrial fission and quality control networks are activated in response to lipid infusion which occurs independent of changes in mitochondrial content or capacity and contributes to the onset of insulin resistance in healthy humans. Authors conclude that treatments that limit lipid-induced activation of mitochondrial fission and/or quality control processes may have therapeutic value in the treatment of insulin resistance.
Abstract
BACKGROUND AND AIMS A diminution in skeletal muscle mitochondrial function due to ectopic lipid accumulation and excess nutrient intake is thought to contribute to insulin resistance and the development of type 2 diabetes. However, the functional integrity of mitochondria in insulin-resistant skeletal muscle remains highly controversial. METHODS 19 healthy adults (age:28.4 ± 1.7 years; BMI:22.7 ± 0.3 kg/m2) received an overnight intravenous infusion of lipid (20% Intralipid) or saline followed by a hyperinsulinemic-euglycemic clamp to assess insulin sensitivity using a randomized crossover design. Skeletal muscle biopsies were obtained after the overnight lipid infusion to evaluate activation of mitochondrial dynamics proteins, ex-vivo mitochondrial membrane potential, ex-vivo oxidative phosphorylation and electron transfer capacity, and mitochondrial ultrastructure. RESULTS Overnight lipid infusion increased dynamin related protein 1 (DRP1) phosphorylation at serine 616 and PTEN-induced kinase 1 (PINK1) expression (P = 0.003 and P = 0.008, respectively) in skeletal muscle while reducing mitochondrial membrane potential (P = 0.042). The lipid infusion also increased mitochondrial-associated lipid droplet formation (P = 0.011), the number of dilated cristae, and the presence of autophagic vesicles without altering mitochondrial number or respiratory capacity. Additionally, lipid infusion suppressed peripheral glucose disposal (P = 0.004) and hepatic insulin sensitivity (P = 0.014). CONCLUSIONS These findings indicate that activation of mitochondrial fission and quality control occur early in the onset of insulin resistance in human skeletal muscle. Targeting mitochondrial dynamics and quality control represents a promising new pharmacological approach for treating insulin resistance and type 2 diabetes. CLINICAL TRIAL REGISTRATION NCT02697201, ClinicalTrials.gov.
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Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women.
Yoshino, M, Yoshino, J, Kayser, BD, Patti, GJ, Franczyk, MP, Mills, KF, Sindelar, M, Pietka, T, Patterson, BW, Imai, SI, et al
Science (New York, N.Y.). 2021;372(6547):1224-1229
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Nicotinamide adenine dinucleotide (NAD+) is a co-substrate for NAD+-consuming enzymes that are essential in the regulation of diverse biological processes. The aim of this study was to determine the effects of nicotinamide mononucleotide (NMN) supplementation on i) body composition, ii) skeletal muscle insulin sensitivity, and insulin signalling; and iii) muscle NAD+ content and global gene expression profile. This study is a 10-week, randomized, placebo-controlled, double-blind trial in postmenopausal women with prediabetes who were overweight or obese. Twenty-five postmenopausal women with prediabetes were randomised to the placebo group (n=12) or the NMN group (n=13). Results show that 10 weeks of NMN supplementation increases muscle insulin signalling and muscle insulin sensitivity in postmenopausal women with prediabetes who are overweight or obese. Authors conclude that the precise mechanism(s) responsible for these metabolic effects and the potential metabolic benefits of NMN supplementation in other patient populations remain to be explored.
Abstract
In rodents, obesity and aging impair nicotinamide adenine dinucleotide (NAD+) biosynthesis, which contributes to metabolic dysfunction. Nicotinamide mononucleotide (NMN) availability is a rate-limiting factor in mammalian NAD+ biosynthesis. We conducted a 10-week, randomized, placebo-controlled, double-blind trial to evaluate the effect of NMN supplementation on metabolic function in postmenopausal women with prediabetes who were overweight or obese. Insulin-stimulated glucose disposal, assessed by using the hyperinsulinemic-euglycemic clamp, and skeletal muscle insulin signaling [phosphorylation of protein kinase AKT and mechanistic target of rapamycin (mTOR)] increased after NMN supplementation but did not change after placebo treatment. NMN supplementation up-regulated the expression of platelet-derived growth factor receptor β and other genes related to muscle remodeling. These results demonstrate that NMN increases muscle insulin sensitivity, insulin signaling, and remodeling in women with prediabetes who are overweight or obese (clinicaltrial.gov NCT03151239).
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A Single Bout of Premeal Resistance Exercise Improves Postprandial Glucose Metabolism in Obese Men with Prediabetes.
Bittel, AJ, Bittel, DC, Mittendorfer, B, Patterson, BW, Okunade, AL, Abumrad, NA, Reeds, DN, Cade, WT
Medicine and science in sports and exercise. 2021;53(4):694-703
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Prediabetes is a metabolic condition defined by elevated fasting (impaired fasting glucose) and/or postprandial (impaired glucose tolerance) plasma glucose. The aim of this study was to determine the effects of a single bout of resistance exercise on postprandial glucose metabolism following a mixed meal in obese, sedentary men with prediabetes. This study is a randomised, cross-over study design which enrolled ten participants. Participants were aged 39-62 years, obese, and demonstrated insulin resistance with compensatory increases in beta cell function. Results show that a single bout of resistance exercise performed 4.5 hours before a mixed meal (as opposed to an oral glucose tolerance test) reduced total postprandial glucose appearance, increased insulin sensitivity, and reduced the glycaemic response to a mixed meal. However, it did not have effect on glucose oxidation in obese men with prediabetes. Improvements in insulin sensitivity were complemented by reduced postprandial insulin concentration. Authors conclude that further investigation is needed to elucidate how resistance exercise affects exogenous (meal) vs endogenous postprandial glucose metabolism, and if additional bouts of exercise (i.e. training) produce superior outcomes for this population.
Abstract
INTRODUCTION Prediabetes is a major risk factor for type 2 diabetes and cardiovascular diseases. Although resistance exercise (RE) is recommended for individuals with prediabetes, the effects of RE on postprandial glucose metabolism in this population are poorly understood. Therefore, the purpose of this study was to elucidate how RE affects postprandial glucose kinetics, insulin sensitivity, beta cell function, and glucose oxidation during the subsequent meal in sedentary men with obesity and prediabetes. METHODS We studied 10 sedentary men with obesity (body mass index, 33 ± 3 kg·m-2) and prediabetes by using a randomized, cross-over study design. After an overnight fast, participants completed either a single bout of whole-body RE (seven exercises, 3 sets of 10-12 repetitions at 80% one-repetition maximum each) or an equivalent period of rest. Participants subsequently completed a mixed meal test in conjunction with an intravenous [6,6-2H2]glucose infusion to determine basal and postprandial glucose rate of appearance (Ra) and disappearance (Rd) from plasma, insulin sensitivity, and the insulinogenic index (a measure of beta cell function). Skeletal muscle biopsies were obtained 90 min postmeal to evaluate pyruvate-supported and maximal mitochondrial respiration. Whole-body carbohydrate oxidation was assessed using indirect calorimetry. RESULTS RE significantly reduced the postprandial rise in glucose Ra and plasma glucose concentration. Postprandial insulin sensitivity was significantly greater after RE, whereas postprandial plasma insulin concentration was significantly reduced. RE had no effect on the insulinogenic index, postprandial pyruvate respiration, or carbohydrate oxidation. CONCLUSION/INTERPRETATION A single bout of RE has beneficial effects on postprandial glucose metabolism in men with obesity and prediabetes by increasing postprandial insulin sensitivity, reducing the postprandial rise in glucose Ra, and reducing postprandial plasma insulin concentration.
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Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial.
Hernández-González, T, González-Barrio, R, Escobar, C, Madrid, JA, Periago, MJ, Collado, MC, Scheer, FAJL, Garaulet, M
FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2021;35(7):e21649
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Expert Review
Conflicts of interest:
None
Take Home Message:
Important from a public health perspective:
- To highlight the potential benefits of chocolate consumption in post-menopausal females.
- To promote more awareness of how the timing of dietary intake can impact health outcomes.
- Consumption of a moderate amount of milk chocolate may support gut health in post-menopausal women.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
The authors highlight food timing is a relevant factor in weight control and that eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota composition and function, as well as sleep and circadian-related variables.
Aim
To evaluate if high-energy and high-sugar food such as chocolate during a short-term period of two weeks in the morning or in the evening/at night, affects energy balance and differentially impact body weight or body fat distribution due to changes in energy intake, substrate oxidation, sleep- and circadian-related variables, or microbiota composition and their metabolic activity.
Study Design
A randomised cross over trial of 19 postmenopausal women (age 52+4 years) who ate 100 g of milk chocolate for 2 weeks within an hour of waking up together with breakfast (MC), 100 g of milk chocolate for 2 weeks within the hour before bedtime (EC), and no chocolate for 2 weeks (N), in a randomised order. There was a week of washout between each condition in which volunteers followed their usual dietary habits but without eating any chocolate.
The milk chocolate composition was 18.1 g cocoa, 31 g fat, 58.4 g carbohydrates (of which 57.5 g were sugar), 6.3 proteins, and 1.8 g fiber per 100 g of chocolate. It contained 215 mg of theobromine, 2.06 mg of caffeine, and 854 mg of total polyphenols (mainly epicatechin and catechin) per 100 g of chocolate.
Outcomes Measured
- Dietary intake: Total energy intake, macronutrient composition, caffeine, and polyphenol content during the 14 days of each condition were analyzed with the nutritional evaluation software
- Hunger and Sweets Appetite (VAS) assessments, at baseline and during the last 3 days.
- Wrist temperature and activity during the last 7 days
- Sleep duration, number of awakening and siesta frequency and duration were self-reported during 7 days at baseline and 14 days during each condition.
- Saliva for cortisol measurements was collected at baseline (on the penultimate day) and during each chocolate condition (on the penultimate day).
- Fasting whole-blood glucose concentration was determined on the last day of each condition.
- Analysis of microbiota composition was assessed in the morning on the first and penultimate day of each condition.
- Analysis of Short-Chain Fatty Acids (SCFAs).
- Statistical analysis: Data normality was confirmed by the Shapiro–Wilk and Kolmogorov–Smirnov tests. To obtain additional information about the relationships between bacterial groups and SCFAs, a principal component analysis (PCA) was performed. For the main outcome measures of interest a two-tailed P-value of < .05 was considered as statistically significant.
Results
- 14 days of chocolate intake (extra 542 kcal) did not gain significant body weight when eating ad libitum within each condition
- Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day).
- Evening Consumption increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05).
- Daily cortisol levels were lower when eating chocolate in the morning than at evening/night.
- Morning Consumption reduced fasting glucose (4.4%) and waist circumference (−1.7%) and increased lipid oxidation (+25.6%).
- Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05).
- Heat map of wrist temperature and sleep records showed that Evening Consumption induced more regular timing of sleep episodes with lower variability of sleep onset among days than Morning Consumption (60 min vs 78 min; P = .028).
Conclusions
The authors conclude that having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the “when” we eat is a relevant factor to consider in energy balance and metabolism.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
In post-menopausal females:
- Chocolate consumption can help to reduce hunger and desire for sweets with no significant body weight gain due to the chocolate’s extra calories, especially when consumed in the morning,
- 100g chocolate in the morning may help to reduce stress, fasting glucose and waist circumference but longer-term studies are needed
- 100g chocolate intake in the morning or evening increases microbiota composition and diversity.
- 100g chocolate consumption during the evening/night increases the production of SCFAs and supports sleep timing by regulating sleep onset.
chocolate intake at evening/night could also be advisable for next morning performance during high intensity exercises or prolonged exercises because it helps avoid hepatic and muscle glycogen depletion
Considerations for future research:
- More extensive research could investigate interventions of a longer period and in different population groups.
- Further studies could evaluate the differences in these results between milk and dark chocolate
Abstract
Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian-related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning (MC), in the evening/at night (EC), or no chocolate (N) for 2 weeks and ate any other food ad libitum. Our results show that 14 days of chocolate intake did not increase body weight. Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day). EC increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05). MC reduced fasting glucose (4.4%) and waist circumference (-1.7%) and increased lipid oxidation (+25.6%). Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05). Heat map of wrist temperature and sleep records showed that EC induced more regular timing of sleep episodes with lower variability of sleep onset among days than MC (60 min vs 78 min; P = .028). In conclusion, having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the "when" we eat is a relevant factor to consider in energy balance and metabolism.
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Association between postmenopausal vulvovaginal discomfort, vaginal microbiota, and mucosal inflammation.
Mitchell, CM, Ma, N, Mitchell, AJ, Wu, MC, Valint, DJ, Proll, S, Reed, SD, Guthrie, KA, Lacroix, AZ, Larson, JC, et al
American journal of obstetrics and gynecology. 2021;225(2):159.e1-159.e15
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Close to half of postmenopausal women report bothersome symptoms of vulvar, vaginal or urinary discomfort collectively referred to as genitourinary syndrome of menopause. These are associated with negative impacts on sexual function and quality of life. The study’s hypothesis is that vaginal microbiota and inflammatory markers (i.e. increased Lactobacillus abundance and decreased inflammation) would differ significantly between women with the largest reductions in most bothersome symptom (MBS) severity compared to those women with smaller reductions, regardless of treatment arm. This study is a sub-study (secondary analysis of samples collected) of the Menopause Strategies: Finding Lasting Answers for Symptoms and Health (MsFLASH) Vaginal Health Trial. Of 302 women randomised in the parent trial, 120 were enrolled in this sub-study. Results did not show significant associations between change in MBS severity and vaginal microbiota composition, Lactobacillus dominance, soluble immune markers, vaginal maturation index or vaginal fluid metabolites. Authors conclude that efforts to change superficial features of the vaginal microenvironment, such as pH or Lactobacillus colonization, may not address the primary underlying mechanism that leads to postmenopausal vaginal discomfort and is unlikely to be effective in relieving moderate to severe bothersome symptoms.
Abstract
BACKGROUND Half of all postmenopausal women report symptoms of vulvar, vaginal, or urinary discomfort with substantial impact on sexual function and quality of life; underlying mechanisms leading to symptoms are poorly understood. OBJECTIVE To examine the possibility that the vaginal microbiota and/or mucosal immune response contributes to the severity of bothersome vaginal symptoms, we conducted a substudy of samples from a randomized trial of vaginal treatment for genitourinary syndrome of menopause to compare these features between women whose symptoms improved and women whose symptoms did not improve. STUDY DESIGN This is a secondary analysis of samples collected in a 12-week randomized trial of treatment with vaginal estradiol or moisturizer vs placebo for moderate-severe postmenopausal symptoms of vaginal discomfort. We randomly selected 20 women in each arm with ≥2-point decrease in most bothersome symptom severity (responders) and 20 matched controls with ≤1-point decrease (nonresponders). At 0, 4, and 12 weeks, we characterized vaginal microbiota (16S ribosomal RNA gene sequencing), vaginal fluid metabolites (broad-based metabolomic profiling), vaginal fluid-soluble immune markers (Meso Scale Discovery), pH, and vaginal maturation index. We compared responders with nonresponders at baseline and across all visits using linear mixed models to evaluate associations with microbiota, metabolites, and immune markers, incorporating visit and participant-specific random effects while controlling for treatment arm. RESULTS Here, the mean age of women was 61 years (n=120), and most women (92%) were White. At enrollment, no significant differences were observed between responders and nonresponders in age, most bothersome symptom type or severity, microbiota composition or diversity, Lactobacillus dominance, metabolome, or immune markers. There was a significant decrease in diversity of the vaginal microbiota in both responders and nonresponders (P<.001) over 12 weeks. Although this change did not differ by responder status, diversity was associated with treatment arm: more women in the estradiol arm (63%) had Lactobacillus-dominant, lower diversity bacterial communities than women in the moisturizer (35%) or dual placebo (23%) arms (P=.001) at 12 weeks. The metabolome, vaginal maturation index, and measured immune markers were not associated with responder status over the 12 weeks but varied by treatment arm. CONCLUSION Postmenopausal vaginal symptom severity was not significantly associated with vaginal microbiota or mucosal inflammatory markers in this small study. Women receiving vaginal estradiol experienced greater abundance of lactobacilli and lower vaginal pH at end of treatment.
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Association of vaginal bacterial communities and reproductive outcomes with prophylactic antibiotic exposure in a subfertile population undergoing in vitro fertilization: a prospective exploratory study.
Eskew, AM, Stout, MJ, Bedrick, BS, Riley, JK, Herter, BN, Gula, H, Jungheim, ES, Wylie, KM
F&S science. 2021;2(1):71-79
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Approximately 1 in 8 couples receive infertility services in their lifetime. However, despite the increasing usage of in vitro fertilisation (IVF) technologies, the success rate, as measured using live birth rates, is just <50% in women <35 years of age. A low-diversity, Lactobacillus-dominated microbiome in the female reproductive tract has been thought to be a sign of optimal reproductive health, whereas an increased microbial diversity has been shown to be associated with poorer reproductive outcomes. The aims of this study were to (a) explore the effect of prophylactic azithromycin treatment on the vaginal bacterial microbiome longitudinally throughout an IVF cycle and (b) determine whether the characteristics of the vaginal bacterial communities are associated with clinical outcomes. This study is an a priori prospective exploratory cohort study conducted as a part of an ongoing randomized, controlled noninferiority trial. Subjects in the parent trial were randomly assigned to an azithromycin group or no-azithromycin group. The female subjects of the parent trial who were aged between 18–43 years and undergoing the first IVF cycle with a fresh embryo transfer were eligible for this study (n=27). Results show that in vaginal microbiome samples taken at the time of egg retrieval and embryo transfer, changes in the taxonomic composition, alpha diversity, and beta diversity are not associated with azithromycin [antibiotic] exposure at the time of gonadotropin initiation. Furthermore, bacterial community structures at baseline are not predictive of those at the time of embryo transfer. Authors conclude that their findings highlight the importance of timing in the assessment of vaginal microbiome to determine its associations with reproductive outcomes.
Abstract
OBJECTIVE To determine whether prophylactic azithromycin is associated with the vaginal bacterial microbiome and clinical outcomes in subfertile women undergoing in vitro fertilization (IVF). DESIGN Prospective exploratory cohort study. SETTING Single academic fertility center. PATIENTS Subfertile women aged 18-43 years undergoing their first IVF cycle and fresh embryo transfer. INTERVENTION Primary exposure to prophylactic azithromycin (1 g orally) once at baseline. MAIN OUTCOME MEASURES The primary outcome was the effect of azithromycin on the vaginal microbiome compared with a no-azithromycin group at 3 time points throughout the IVF cycle (baseline, retrieval, and embryo transfer). The secondary outcomes were associations of vaginal bacterial communities with clinical outcomes. RESULTS A planned a priori exploratory cohort of 27 subjects (12 in the azithromycin treatment group and 15 in the no-azithromycin group) contributed 79 vaginal swabs for the analysis as part of an ongoing randomized, controlled noninferiority trial. No specific taxa were associated with azithromycin or pregnancy at any time point. Azithromycin did not affect alpha diversity or community stability. Although there were trends of a lower bacterial load and higher percentage of Lactobacillus species in the azithromycin group at the time of transfer, these were not statistically significant. In women who did not become pregnant, the percentage of Lactobacillus species was lower (P = .048; Hodges-Lehmann estimate of difference, 0.41; 95% confidence interval, 0.08-0.65) and the change in community composition over time was higher. The percentage of Lactobacillus species at baseline was not predictive of the percentage of Lactobacillus species at the time of embryo transfer. CONCLUSIONS Prophylactic azithromycin at baseline is not associated with changes in vaginal bacterial communities. Bacterial community features at the time of embryo transfer are associated with pregnancy. Bacterial community structures at baseline are not predictive of those at the time of embryo transfer. CLINICAL TRIAL REGISTRATION NUMBER NCT03386227.