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The impact of plant-based diets on female bone mineral density: Evidence based on seventeen studies.Medicine Nov 2021An increase in awareness of plant-based diets has brought forth numerous studies on bone mineral density (BMD). The present systematic review and meta-analysis was... (Meta-Analysis)
Meta-Analysis
BACKGROUND
An increase in awareness of plant-based diets has brought forth numerous studies on bone mineral density (BMD). The present systematic review and meta-analysis was designed to compare the effect between plant-based diets and omnivores on female BMD.
METHODS
We searched the Cochrane Library, PubMed, EMBASE, and Web of Science and up to July 1, 2020. Mean difference (MD) with its 95% confidence interval (CI) was estimated to compare the outcomes of the groups. We compared BMD at the lumbar spine, femoral neck and whole body respectively between plant-based diets and omnivores. In addition, we performed subgroup analyses according to different clinical characteristics for further exploration. Two reviewers assessed trial quality and extracted data independently. All statistical analyses were performed using standard statistical procedures provided in Review Manager 5.2.
RESULTS
A total of 17 cross-sectional studies including 13,888 patients were identified for the present meta-analysis. Our pooled result indicated that population with plant-based diets had lower BMD than omnivores at the lumbar spine (MD -0.03; 95% CI -0.04 to -0.02; P < .0001), femoral neck (MD -0.04; 95% CI -0.05 to -0.03; P < .00001) and whole body (MD -0.04; 95% CI -0.06 to -0.01; P = .01), respectively. Further exploration indicated that especially females with plant-based diets experienced significantly lower BMD at lumbar spine (MD -0.03; 95% CI -0.04 to -0.02; 3173 pts), femoral neck (MD -0.04; 95% CI -0.05 to -0.03; 10,656 pts) and whole body (MD -0.05; 95% CI -0.10 to -0.00; P = .04). In addition, we performed subgroup analyses and found lower BMD at lumbar spine and femoral neck in both vegetarians and vegans.
CONCLUSIONS
The present meta-analysis indicated that plant-based diets may be correlated with lower BMD of women when compared with omnivore population. However, this does not diminish the fact that a plant-based diet can be a harmful option to the overall bone health of population and more prospective researches are needed to clear the impact of plant-based diets on bone health.
Topics: Bone Density; Diet, Vegetarian; Female; Femur Neck; Humans; Lumbar Vertebrae
PubMed: 34797275
DOI: 10.1097/MD.0000000000027480 -
Advances in Nutrition (Bethesda, Md.) Feb 2022Altered immune cell phenotype and chronic inflammation are key features shared by various chronic diseases. Evidence from nutritional interventions aimed at alleviating... (Meta-Analysis)
Meta-Analysis
Altered immune cell phenotype and chronic inflammation are key features shared by various chronic diseases. Evidence from nutritional interventions aimed at alleviating inflammation could be a promising approach for the prevention of adverse health outcomes. We therefore aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize the recent evidence on the effects of dietary patterns on inflammatory and immune-related biomarkers in humans. PubMed, Medline, and Web of Science databases were searched for publications up to October 2020. In total, 22 RCTs were included in the meta-analysis conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Mediterranean diet appeared as the dietary pattern that showed the most prominent reductions of inflammatory biomarkers such as IL-6 [mean difference (MD): -1.07 pg/mL (95% CI: -1.94, -0.20); I2: 96%], IL-1β [MD: -0.46 pg/mL (95% CI: -0.66, -0.25); I2: 0%], and C-reactive protein [MD: -1.00 mg/L (95% CI: -2.02, 0.01); I2: 100%]. No substantial effects were observed for the additional dietary patterns studied in intervention research, including the Dietary Adherence to Stop Hypertension diet, and the vegetarian or vegan diets. Future large-scale multifactorial intervention studies are warranted to allow direct comparison of various dietary patterns in relation to a range of biomarkers reflecting multiple inflammatory and immune-related pathways.
Topics: Biomarkers; Diet, Mediterranean; Humans; Immunity; Inflammation; Randomized Controlled Trials as Topic
PubMed: 34607347
DOI: 10.1093/advances/nmab086 -
Nutrients Aug 2021Vegetarian dietary patterns provide health benefits for cardiovascular health; however, the studies examining the association of vegetarian diets with stroke incidence... (Meta-Analysis)
Meta-Analysis
Vegetarian dietary patterns provide health benefits for cardiovascular health; however, the studies examining the association of vegetarian diets with stroke incidence showed inconsistent findings. We systematically evaluated the risk of incident stroke among vegetarians (diets excluding meat, poultry, fish, and seafood) compared among nonvegetarians. A systematic search of PubMed, EMBASE, Cochrane Library, and Web of Science was performed until 20 May 2021. Prospective cohort studies comparing the risk estimates for incident stroke between vegetarians and nonvegetarians were included. Of 398 articles identified in the database search, data from seven cohort studies (408 total stroke cases in 29,705 vegetarians and 13,026 total stroke cases in 627,728 nonvegetarians) were included. The meta-analysis revealed no significant association between adhering to the vegetarian dietary patterns and the risk of incident stroke (HR = 0.86; 95% CI = 0.67-1.11; I = 68%, = 7). Subgroup analyses suggested that studies conducted in Asia and those with a mean baseline age of participants 50-65 years showed a lower risk of stroke in vegetarians. Moreover, no significant association between vegetarian diets and the risk of ischemic stroke (HR = 0.56; 95% CI = 0.22-1.42; I = 82%, = 3) or hemorrhagic stroke (HR = 0.77; 95% CI = 0.19-3.09; I = 85%, = 2) was found. To be conclusive, no strong relationship between vegetarian diets and the incidence of stroke was observed. Given the limited certainty of evidence from NutriGrade, future well-designed studies are warranted to provide solid evidence on this topic.
Topics: Aged; Cohort Studies; Diet; Diet, Vegetarian; Female; Humans; Male; Middle Aged; Prospective Studies; Stroke; Vegetarians
PubMed: 34578897
DOI: 10.3390/nu13093019 -
Nutrition Reviews Apr 2022The obesity epidemic is a main driver of the chronic disease epidemic; however, present treatment approaches have suboptimal efficacy.
CONTEXT
The obesity epidemic is a main driver of the chronic disease epidemic; however, present treatment approaches have suboptimal efficacy.
OBJECTIVES
To assess the efficacy of plant-predominant (vegan, vegetarian, plant-based whole foods [PBWFs]) diets in treating obesity and its main cardiometabolic sequelae: hyperlipidemia (HLD); indices of insulin resistance, glycemic control, and diabetes mellitus type 2 (DM2); and cardiovascular disease (CVD), including hypertension (HTN).
DATA SOURCES
A systematic search of multiple databases was conducted for articles published between November 2019 and February 2020; databases searched included: PubMed, Medline (Ovid), Cochrane, CENTRAL, and CINAHL.
DATA EXTRACTION AND ANALYSIS
All interventional trials (randomized controlled trials [RCTs] and trials of non-randomized experimental design) that met the inclusion criteria (English language, duration of at least 4 weeks, primary end point congruent with above objectives, no major flaws in research design that would prevent interpretation) were included in the review. A total of 3135 articles were scanned and 84 were selected. The articles were collated and summarized in 2 evidence tables. Risk of bias for RCTs was assessed using the Cochrane Risk-of-Bias tool 2 as a guide. For non-randomized trials, higher risk of bias was assumed, and the JBI Critical Appraisal tool was used as a guide to determine inclusion.
RESULTS
Plant-based diets, in general, demonstrated improved weight control and cardiometabolic outcomes related to lipids, cardiovascular end points, blood pressure, insulin sensitivity, A1C, and fasting glucose, and a lower risk of diabetes compared with usual diets and in some cases standard health-oriented diets such as the American Heart Association (AHA), American Diabetic Association (ADA), and Mediterranean diets. Preliminary studies suggest plant-predominant diets practiced as part of healthy lifestyle interventions may stabilize or even reverse DM 2 and CVD. The acceptability and sustainability of plant-predominant diets where measured were generally similar to other health-oriented diets.
CONCLUSION
Plant-predominant diets can play a major role in reversing the obesity and chronic disease epidemics. In the setting of sustained lifestyle intervention programs, they may arrest or even reverse DM2 and CVD. Further higher-level RCTs are needed to confirm and expand on these findings.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet, Mediterranean; Diet, Vegan; Humans; Insulin Resistance; Obesity; Outcome Assessment, Health Care
PubMed: 34498070
DOI: 10.1093/nutrit/nuab060 -
Nutrients Jul 2021The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut...
The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut microbiota can be considered a virtual organ of the body, playing a pivotal role in health maintenance. Dietary habits contribute to gut microbiota composition, and evidence from observational and intervention studies suggest that vegan diets may promote health, potentially through affecting the diverse ecosystem of beneficial bacteria in the gut. A systematic literature search was conducted on PubMed and Scopus to identify studies investigating the microbiota composition in vegans. Vegans are defined as people excluding food products that are derived from animals from their diet. Nine observational studies were identified. The main outcome of the systematic review was an increase in Bacteroidetes on the phylum level and a higher abundance of on the genus level. In conclusion, the present systematic literature review highlighted some benefits of a vegan diet but also demonstrated the complexity of evaluating results from gut microbiota research. The available evidence only consisted of cross-sectional studies, therefore suggesting the need for well-designed randomised controlled trials. Furthermore, the quality assessment of the studies included in the review suggested a lack of standardised and validated methods for participant selection as well as for faecal sampling and faecal analysis.
Topics: Adult; Bacteria; Diet, Healthy; Diet, Vegan; Dysbiosis; Feces; Female; Gastrointestinal Microbiome; Humans; Intestines; Male; Middle Aged; Nutritive Value
PubMed: 34371912
DOI: 10.3390/nu13072402 -
Public Health Nutrition Oct 2021To identify individual-, provider- and system/environmental-level barriers and facilitators affecting cardiac rehabilitation (CR) participants' adherence to dietary...
OBJECTIVE
To identify individual-, provider- and system/environmental-level barriers and facilitators affecting cardiac rehabilitation (CR) participants' adherence to dietary recommendations.
DESIGN
A systematic review of the medical literature was conducted. Six databases were searched from inception through March 2021: APA PsycInfo, CINAHL, Embase, Emcare, Medline and PubMed. Only those studies referring to barriers and facilitators reported by CR participants were considered. Pilot and case report studies, non-peer-reviewed literature and studies published in a language other than English, Portuguese or Spanish were excluded.
RESULTS
Data were extracted and analysed on the basis of individual-, provider- and system/environmental-level factors. Of 2083 initial citations, sixteen studies were included, with nine being qualitative and seven observational in design. From these, ten multi-level barriers and seven multi-level facilitators were identified. Dietary recommendations included developing healthy eating habits, transitioning to vegetarian-rich diets and increasing fish oil and n-3 intake. Only one study reported on all of the nutrition education programme factors recommended by the Workgroup for Intervention Development and Evaluation Research.
CONCLUSION
To the best of our knowledge, this review is the first to summarise specific barriers and facilitators to recommendation adherence among CR participants. Few of the studies offered any conclusions regarding programme design that could facilitate improved dietary adherence practices. Future studies should aim to explore patient perspectives on the nutritional patterns and recommendations outlined in the Mediterranean Diet, the Dietary Approaches to Stop Hypertension Diet, Vegetarian or Vegan diets and the Portfolio Diet.
Topics: Cardiac Rehabilitation; Diet, Healthy; Diet, Mediterranean; Ethnicity; Feeding Behavior; Humans
PubMed: 34344495
DOI: 10.1017/S1368980021002962 -
Nutrients Jun 2021A protective effect of vegan diets on health outcomes has been observed in previous studies, but its impact on diabetes is still debated. The aim of this review is to...
A protective effect of vegan diets on health outcomes has been observed in previous studies, but its impact on diabetes is still debated. The aim of this review is to assess the relationship between vegan diets and the risk for type 2 diabetes (T2D) along with its effect on glycemic control and diabetes-related complications. In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, Pubmed and Cochrane library databases were systematically searched for all relevant studies. Seven observational and eight randomized controlled (RCTs) studies were included. The methodological quality of studies was assessed using the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies and the Cochrane Risk of Bias Tool for RCTs. We found that a vegan diet is associated with lower T2D prevalence or incidence and in T2D patients decreases high glucose values and improves glucose homeostasis, as reported from the majority of included studies. This approach seems to be comparable to other recommended healthful eating models, but as it may have potential adverse effects associated with the long-term exclusion of some nutrients, appropriate nutritional planning and surveillance are recommended, particularly in specific groups of diabetic patients such as frail elderly, adolescents, and pregnant or breastfeeding women.
Topics: Diabetes Mellitus, Type 2; Diet, Vegan; Female; Glycemic Control; Humans; Incidence; Male; Observational Studies as Topic; Prevalence; Randomized Controlled Trials as Topic
PubMed: 34205679
DOI: 10.3390/nu13062123 -
Archives of Osteoporosis Jun 2021The increased consumption of plant-based diets has encouraged studies of bone mineral density (BMD). The present systematic review and meta-analysis compared the effects... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The increased consumption of plant-based diets has encouraged studies of bone mineral density (BMD). The present systematic review and meta-analysis compared the effects of plant-based and omnivorous diets on BMD.
METHODS
We searched the Cochrane Library, PubMed, EMBASE, and the Web of Science to July 1, 2020. We used the mean differences (MDs) with 95% CIs to compare group outcomes. We compared the lumbar spine, femoral neck, and whole-body BMDs of those on plant-based and omnivorous diets. We performed subgroup analyses by various clinical characteristics. Two reviewers independently assessed trial quality and extracted data. All statistical analyses were performed using Review Manager version 5.2.
RESULTS
A total of 17 cross-sectional studies including 13,888 patients were identified. The pooled results indicated that those on plant-based diets (compared to omnivores) exhibited lower BMDs at the lumbar spine (MD - 0.04; 95% CI - 0.06 to - 0.02; P < 0.0001) and femoral neck (MD - 0.04; 95% CI - 0.05 to - 0.02; P < 0.00001), and a reduced whole-body BMD (MD - 0.03; 95% CI - 0.06 to - 0.01; P = 0.0009). Both vegetarians and vegans exhibited lower lumbar spine, femoral neck, and whole-body BMDs than omnivores.
CONCLUSIONS
Plant-based diets were associated with lower BMDs than those of an omnivore population. Plant-based diets may compromise overall bone health; prospective research is required.
Topics: Bone Density; Cross-Sectional Studies; Diet; Femur Neck; Humans; Lumbar Vertebrae; Prospective Studies
PubMed: 34145511
DOI: 10.1007/s11657-021-00955-0 -
International Journal of Environmental... May 2021Fibromyalgia (FM) is a chronic non-degenerative disease characterized by the presence of multiple symptoms such as chronic pain, which negatively influence the quality... (Review)
Review
Fibromyalgia (FM) is a chronic non-degenerative disease characterized by the presence of multiple symptoms such as chronic pain, which negatively influence the quality of life of sufferers, most of whom are women. Currently, there is no effective treatment to limit the impact of these symptoms. The aim of this research is to review the scientific evidence on the effect of following a vegetarian or vegan diet on fibromyalgia patients. A systematic review included the original articles that answered the research question. These articles were in 2021 in the PubMed, Web of Science and Scopus databases. The research used the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. No time restriction was applied, and grey literature was not included. The evaluation of the methodological quality of the articles was carried out using the following different scales: STROBE (strengthening the reporting of observational studies in epidemiology), PEDro (Physiotherapy Evidence Database), and MMAT (Mixed Methods Appraisal Tool) scales. A total of 88 studies were analyzed, of which 6 investigations were included in this systematic review ( = 4 clinical trials and = 2 cohort studies). These investigations show significant improvements in biochemical parameters, quality of life, quality of sleep, pain at rest and general health status when following mainly plant-based dietary patterns. In conclusion, these findings are promising but interpretation of the findings is limited due to the methodological quality of the studies. Well-designed clinical trials are needed to consolidate these dietary recommendations in FM patients.
Topics: Diet; Diet, Vegan; Female; Fibromyalgia; Humans; Male; Quality of Life; Vegetarians
PubMed: 34066603
DOI: 10.3390/ijerph18094955 -
Nutrition Reviews May 2022Mental health may be influenced by some dietary patterns. Among common elements of beneficial patterns is high fruit and vegetable intake. However, no systematic review...
CONTEXT
Mental health may be influenced by some dietary patterns. Among common elements of beneficial patterns is high fruit and vegetable intake. However, no systematic review has been conducted to date, to our knowledge, that has assessed the influence of fruit and vegetable dietary patterns on a broad spectrum of mental health.
OBJECTIVE
We conducted a systematic review, using the PRISMA guidelines, of the observational studies analyzing the association between the dietary pattern of fruit and vegetables and the broad aspects of mental health in adult women.
DATA SOURCES
The databases PubMed and Web of Science were searched, and additional manual search for observational peer-reviewed studies was conducted for studies published until June 2019.
DATA EXTRACTION
A total of 5911 studies were extracted and verified based on title and abstract for the inclusion criteria. All procedures were conducted independently by 2 researchers. The final number of included studies was 30. The review was structured around the type of observed outcome.
DATA ANALYSIS
The included studies had defined habitual intake associated with dietary patterns with the intake of specific fruit and/or vegetables, and/or fruit or vegetable products (eg, juices), as well as any aspect of the broad spectrum of general mental health. The Newcastle-Ottawa Scale was used to assess bias. The observed association was not stated in all the included studies; some of them revealed a reverse relationship, but only for the vegetarian/vegan diet. A vegetarian diet may be characterized by high consumption of fruits and vegetables, but it sometimes may not be properly balanced, due to excluded products. This may be the reason of observed situation.
CONCLUSIONS
A general positive influence was observed for the dietary patterns characterized by high consumption of fruit and vegetables and of fruit or vegetable products by women.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO registration no. CRD42019138148.
Topics: Adult; Diet; Diet, Vegetarian; Female; Fruit; Humans; Mental Health; Vegetables
PubMed: 34041545
DOI: 10.1093/nutrit/nuab007