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Nutrients May 2020Vegan and vegetarian diets are becoming increasingly popular. Dietary restrictions may increase the risk of iodine deficiency. This systematic review aims to assess...
Vegan and vegetarian diets are becoming increasingly popular. Dietary restrictions may increase the risk of iodine deficiency. This systematic review aims to assess iodine intake and status in adults following a vegan or vegetarian diet in industrialised countries. A systematic review and quality assessment were conducted in the period May 2019-April 2020 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were identified in Ovid MEDLINE, Embase, Web of Science, PubMed, Scopus, and secondary sources. Fifteen articles met inclusion criteria. Participants included 127,094 adults (aged ≥ 18 years). Vegan groups presented the lowest median urinary iodine concentrations, followed by vegetarians, and did not achieve optimal status. The highest iodine intakes were recorded in female vegans (1448.0 ± 3879.0 µg day) and the lowest in vegetarians (15.6 ± 21.0 µg day). Omnivores recorded the greatest intake in 83% of studies. Seaweed contributed largely to diets of vegans with excessive iodine intake. Vegans appear to have increased risk of low iodine status, deficiency and inadequate intake compared with adults following less restrictive diets. Adults following vegan and vegetarian diets living in countries with a high prevalence of deficiency may be more vulnerable. Therefore, further monitoring of iodine status in industrialised countries and research into improving the iodine intake and status of adults following vegan and vegetarian diets is required.
Topics: Adolescent; Adult; Diet, Vegan; Eating; Female; Humans; Iodine; Male; Middle Aged; Nutritional Physiological Phenomena; Nutritional Status; Risk; Seaweed; Vegans; Vegetarians; Young Adult
PubMed: 32486114
DOI: 10.3390/nu12061606 -
The Cochrane Database of Systematic... Feb 2021Diet plays a major role in the aetiology of cardiovascular disease (CVD) and as a modifiable risk factor is the focus of many prevention strategies. Recently vegan diets... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Diet plays a major role in the aetiology of cardiovascular disease (CVD) and as a modifiable risk factor is the focus of many prevention strategies. Recently vegan diets have gained popularity and there is a need to synthesise existing clinical trial evidence for their potential in CVD prevention.
OBJECTIVES
To determine the effectiveness of following a vegan dietary pattern for the primary and secondary prevention of CVD.
SEARCH METHODS
We searched the following electronic databases on 4 February 2020: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Web of Science Core Collection. We also searched ClinicalTrials.gov in January 2021. We applied no language restrictions.
SELECTION CRITERIA
We selected randomised controlled trials (RCTs) in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). A vegan dietary pattern excludes meat, fish, eggs, dairy and honey; the intervention could be dietary advice, provision of relevant foods, or both. The comparison group received either no intervention, minimal intervention, or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of 12 weeks or more, defined as the intervention period plus post-intervention follow-up.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed studies for inclusion, extracted data and assessed risks of bias. We used GRADE to assess the certainty of the evidence. We conducted three main comparisons: 1. Vegan dietary intervention versus no intervention or minimal intervention for primary prevention; 2. Vegan dietary intervention versus another dietary intervention for primary prevention; 3. Vegan dietary intervention versus another dietary intervention for secondary prevention.
MAIN RESULTS
Thirteen RCTs (38 papers, 7 trial registrations) and eight ongoing trials met our inclusion criteria. Most trials contributed to primary prevention: comparisons 1 (four trials, 466 participants randomised) and comparison 2 (eight trials, 409 participants randomised). We included only one secondary prevention trial for comparison 3 (63 participants randomised). None of the trials reported on clinical endpoints. Other primary outcomes included lipid levels and blood pressure. For comparison 1 there was moderate-certainty evidence from four trials with 449 participants that a vegan diet probably led to a small reduction in total cholesterol (mean difference (MD) -0.24 mmol/L, 95% confidence interval (CI) -0.36 to -0.12) and low-density lipoprotein (LDL) cholesterol (MD -0.22 mmol/L, 95% CI -0.32 to -0.11), a very small decrease in high-density lipoprotein (HDL) levels (MD -0.08 mmol/L, 95% CI -0.11 to -0.04) and a very small increase in triglyceride levels (MD 0.11 mmol/L, 95% CI 0.01 to 0.21). The very small changes in HDL and triglyceride levels are in the opposite direction to that expected. There was a lack of evidence for an effect with the vegan dietary intervention on systolic blood pressure (MD 0.94 mmHg, 95% CI -1.18 to 3.06; 3 trials, 374 participants) and diastolic blood pressure (MD -0.27 mmHg, 95% CI -1.67 to 1.12; 3 trials, 372 participants) (low-certainty evidence). For comparison 2 there was a lack of evidence for an effect of the vegan dietary intervention on total cholesterol levels (MD -0.04 mmol/L, 95% CI -0.28 to 0.20; 4 trials, 163 participants; low-certainty evidence). There was probably little or no effect of the vegan dietary intervention on LDL (MD -0.05 mmol/L, 95% CI -0.21 to 0.11; 4 trials, 244 participants) or HDL cholesterol levels (MD -0.01 mmol/L, 95% CI -0.08 to 0.05; 5 trials, 256 participants) or triglycerides (MD 0.21 mmol/L, 95% CI -0.07 to 0.49; 5 trials, 256 participants) compared to other dietary interventions (moderate-certainty evidence). We are very uncertain about any effect of the vegan dietary intervention on systolic blood pressure (MD 0.02 mmHg, 95% CI -3.59 to 3.62) or diastolic blood pressure (MD 0.63 mmHg, 95% CI -1.54 to 2.80; 5 trials, 247 participants (very low-certainty evidence)). Only one trial (63 participants) contributed to comparison 3, where there was a lack of evidence for an effect of the vegan dietary intervention on lipid levels or blood pressure compared to other dietary interventions (low- or very low-certainty evidence). Four trials reported on adverse events, which were absent or minor.
AUTHORS' CONCLUSIONS
Studies were generally small with few participants contributing to each comparison group. None of the included studies report on CVD clinical events. There is currently insufficient information to draw conclusions about the effects of vegan dietary interventions on CVD risk factors. The eight ongoing studies identified will add to the evidence base, with all eight reporting on primary prevention. There is a paucity of evidence for secondary prevention.
Topics: Adult; Bias; Blood Pressure; Cardiovascular Diseases; Cholesterol; Diet, Vegan; Female; Humans; Male; Middle Aged; Primary Prevention; Randomized Controlled Trials as Topic; Recurrence; Secondary Prevention; Triglycerides
PubMed: 33629376
DOI: 10.1002/14651858.CD013501.pub2 -
The British Journal of Nutrition Nov 2015Weight loss is crucial for treating type 2 diabetes mellitus (T2DM). It remains unclear which dietary intervention is best for optimising glycaemic control, or whether... (Review)
Review
The effect of macronutrients on glycaemic control: a systematic review of dietary randomised controlled trials in overweight and obese adults with type 2 diabetes in which there was no difference in weight loss between treatment groups.
Weight loss is crucial for treating type 2 diabetes mellitus (T2DM). It remains unclear which dietary intervention is best for optimising glycaemic control, or whether weight loss itself is the main reason behind observed improvements. The objective of this study was to assess the effects of various dietary interventions on glycaemic control in overweight and obese adults with T2DM when controlling for weight loss between dietary interventions. A systematic review of randomised controlled trials (RCT) was conducted. Electronic searches of Medline, Embase, Cinahl and Web of Science databases were conducted. Inclusion criteria included RCT with minimum 6 months duration, with participants having BMI≥25·0 kg/m2, a diagnosis of T2DM using HbA1c, and no statistically significant difference in mean weight loss at the end point of intervention between dietary arms. Results showed that eleven studies met the inclusion criteria. Only four RCT indicated the benefit of a particular dietary intervention over another in improving HbA1c levels, including the Mediterranean, vegan and low glycaemic index (GI) diets. However the findings from one of the four studies showing a significant benefit are questionable because of failure to control for diabetes medications and poor adherence to the prescribed diets. In conclusion there is currently insufficient evidence to suggest that any particular diet is superior in treating overweight and obese patients with T2DM. Although the Mediterranean, vegan and low-GI diets appear to be promising, further research that controls for weight loss and the effects of diabetes medications in larger samples is needed.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diet; Diet, Mediterranean; Diet, Vegan; Glycated Hemoglobin; Glycemic Index; Humans; MEDLINE; Obesity; Overweight; Randomized Controlled Trials as Topic; Weight Loss
PubMed: 26411958
DOI: 10.1017/S0007114515003475 -
Environmental Research Letters : ERL... Dec 2020The adoption of healthy diets with low environmental impact has been widely promoted as an important climate change mitigation strategy. Typically, these diets are high...
Climate change mitigation through dietary change: a systematic review of empirical and modelling studies on the environmental footprints and health effects of 'sustainable diets'.
The adoption of healthy diets with low environmental impact has been widely promoted as an important climate change mitigation strategy. Typically, these diets are high in plant-sourced and low in animal-sourced and processed foods. Despite the fact that their environmental impacts vary, they are often referred to as 'sustainable diets'. Here we systematically review the available published evidence on the effect of 'sustainable diets' on environmental footprints and human health. Eight databases (OvidSP-Medline, OvidSP-Embase, EBSCO-GreenFILE, Web of Science Core Collection, Scopus, OvidSP-CAB-Abstracts, OvidSP-AGRIS, and OvidSP-Global Health) were searched to identify literature (published 1999-2019) reporting health effects and environmental footprints of 'sustainable diets'. Available evidence was mapped and pooled analysis was conducted by unique combinations of diet pattern, health and environmental outcome. Eighteen studies (412 measurements) met our inclusion criteria, distinguishing twelve non-mutually exclusive sustainable diet patterns, six environmental outcomes, and seven health outcomes. In 87% of measurements (n = 151) positive health outcomes were reported from 'sustainable diets' (average relative health improvement: 4.09% [95% CI -0.10-8.29]) when comparing 'sustainable diets' to current/baseline consumption patterns. Greenhouse gas emissions associated with 'sustainable diets' were on average 25.8%[95%CI -27.0 to -14.6] lower than current/baseline consumption patterns, with vegan diets reporting the largest reduction in GHG-emissions (-70.3% [95% CI: -90.2 to -50.4]), however, water use was frequently reported to be higher than current/baseline diets. Multiple benefits for both health and the environment were reported in the majority (n = 315[76%]) of measurements. We identified consistent evidence of both positive health effects and reduced environmental footprints accruing from 'sustainable diets'. The notable exception of increased water use associated with 'sustainable diets' identifies that co-benefits are not universal and some trade-offs are likely. When carefully designed, evidence-based, and adapted to contextual factors, dietary change could play a pivotal role in climate change mitigation, sustainable food systems, and future population health.
PubMed: 33897807
DOI: 10.1088/1748-9326/abc2f7 -
Diabetes, Metabolic Syndrome and... 2020According to the rising prevalence of obesity and metabolic disorders leading to impaired glucose metabolism, effective strategies to prevent and/or delay the onset of... (Review)
Review
According to the rising prevalence of obesity and metabolic disorders leading to impaired glucose metabolism, effective strategies to prevent and/or delay the onset of disease are of great need. A plant-based diet has been suggested as an effective lifestyle change that may reduce the degree of obesity and improve outcomes related to glucose metabolism. This systematic review aimed to evaluate the effect of a plant-based diet on outcomes related to glucose metabolism. A literature search was conducted in the database PubMed until January 30, 2020. Randomized controlled trials investigating the effect of a plant-based dietary intervention on outcomes related to glucose metabolism in human subjects compared to an omnivorous diet were eligible for inclusion. Of 65 publications identified, nine trials on subjects with overweight/obesity, type 2 diabetes mellitus, or cardiovascular disease were included. Five studies reported that the plant-based intervention significantly improved markers of glycemic control from baseline to end point, of which four revealed a significant improvement in the intervention group compared to the control intervention. The remaining four studies did not observe a significant effect of a plant-based intervention on outcomes related to glucose metabolism. Our findings suggest that a shift to a plant-based diet may lead to favorable effects on glycemic control in individuals diagnosed with type 2 diabetes mellitus and/or obesity. The data were however somewhat conflicting, and the included trials reported results based on different intervention diets and study populations. Overall, no clear conclusions regarding effects of different plant-based diets can be drawn based on the current findings alone.
PubMed: 32884310
DOI: 10.2147/DMSO.S265982 -
Journal of Dairy Science Apr 2024Innovation around cheese is constant in attempts to meet ever-increasing consumer demands. Retail packaging provides a canvas to communicate to consumers added value... (Review)
Review
A systematic review of articles influencing United States retail cheese packaging, labeling, and market trends related to cheese in the marketplace and cheese during consumption.
Innovation around cheese is constant in attempts to meet ever-increasing consumer demands. Retail packaging provides a canvas to communicate to consumers added value from innovations or inherent properties of cheese. Packaging itself may also be the subject of cheese-related innovation. This systematic review of literature organizes research over the past 10 years related to cheese packaging innovation that consumers experience in the marketplace and during consumption of cheese products. The review discusses shipping, displaying cheese at grocery stores, the value of branding, purchasing preferences by demographics, health and nutrition claims, opportunities to highlight protein in cheese, marketing to children, issues of obesity and cheese, diet cheeses, allergens and non-dairy or vegan cheese, opening cheese packaging, cutting of cheese, cooking with cheese, eating cheese, the growing trend of snacking and convenience, and flavor preferences. This review provides helpful insights to cheese producers applying findings from research of various styles of cheeses, cheese marketers communicating effectively to consumers, cheese developers designing new products relevant to recent consumer demands, smaller or specialized companies seeking to differentiate their cheese product through available technology and strategy, and cheese lovers or those with hobbies surrounding food wanting to know recent advancements in cheese packaging. This review is a tool for discovering relevant articles relating to cheese packaging in a marketplace and consumption setting to guide cheese and cheese packaging and labeling innovation in the United States.
PubMed: 38608946
DOI: 10.3168/jds.2023-23977 -
Nutrients Jul 2020Long-term cancer survivors represent a sizeable portion of the population. Plant-based foods may enhance the prevention of cancer-related outcomes in these patients. We... (Meta-Analysis)
Meta-Analysis
Long-term cancer survivors represent a sizeable portion of the population. Plant-based foods may enhance the prevention of cancer-related outcomes in these patients. We aimed to synthesize the current evidence regarding the impact of plant-based dietary patterns (PBDPs) on cancer-related outcomes in the general population and in cancer survivors. Considered outcomes included overall cancer mortality, cancer-specific mortality, and cancer recurrence. A rapid review was conducted, whereby 2234 original articles related to the topic were identified via Pubmed/Medline. We selected 26 articles, which were classified into studies on PBDPs and cancer outcomes at pre-diagnosis: vegan/vegetarian diet ( = 5), provegetarian diet ( = 2), Mediterranean diet ( = 13), and studies considering the same at post-diagnosis ( = 6). Pooled estimates of the associations between the aforementioned PBDPs and the different cancer outcomes were obtained by applying random effects meta-analysis. The few studies available on the vegetarian diet failed to support its prevention potential against overall cancer mortality when compared with a non-vegetarian diet (e.g., pooled hazard ratio (HR) = 0.97; 95% confidence interval (CI): 0.88-1.06). The insufficient number of studies evaluating provegetarian index scores in relation to cancer mortality did not permit a comprehensive assessment of this association. The association between adherence to the Mediterranean diet and cancer mortality reached statistical significance (e.g., pooled HR = 0.84; 95% CI: 0.79-0.89). However, no study considered the influence of prognostic factors on the associations. In contrast, post-diagnostic studies accounted for prognostic factors when assessing the chemoprevention potential of PBDPs, but also were inconclusive due to the limited number of studies on well-defined plant-based diets. Thus, whether plant-based diets before or after a cancer diagnosis prevent negative cancer-related outcomes needs to be researched further, in order to define dietary guidelines for cancer survivors.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Diet, Mediterranean; Diet, Vegetarian; Female; Humans; Male; Middle Aged; Neoplasms; Recurrence; Young Adult
PubMed: 32640737
DOI: 10.3390/nu12072010 -
Nutrients May 2020The beneficial effects of a vegetarian diet on blood pressure (BP) control have been reported in previous systematic reviews; however, so far, their relative... (Meta-Analysis)
Meta-Analysis
The beneficial effects of a vegetarian diet on blood pressure (BP) control have been reported in previous systematic reviews; however, so far, their relative effectiveness is not well established. Here, we performed a systematic review together with trial sequential analysis to determine the effect of a vegetarian diet on the reduction of blood pressure. We searched the randomized controlled trial (RCT) through Medline, PubMed and Cochrane Central Register. Fifteen eligible RCTs with 856 subjects were entered into the analysis. The pooled results demonstrated that vegetarian diet consumption significantly lowered the systolic blood pressure (weighted mean difference (WMD), -2.66 mmHg (95% confidence interval (CI) = -3.76, -1.55, < 0.001) and diastolic BP was WMD, -1.69 95% CI = -2.97, -0.41, < 0.001) as compared to an omnivorous diet. In subgroup analysis, a vegan diet demonstrated a greater reduction in systolic BP (WMD, -3.12 mm Hg; 95% CI = -4.54, -1.70, < 0.001) as compared with a lacto-ovo-vegetarian diet (WMD, -1.75 mm Hg, 95% CI -5.38, 1.88, = 0.05). The vegan diet has showed a similar trend in terms of diastolic blood pressure reduction (WMD, -1.92 mm Hg (95% CI = -3.18, -0.66, < 0.001) but those with a lacto-ovo-vegetarian diet showed no changes in diastolic BP reduction (WMD, 0.00, 95% CI = 0.00, 0.00), =0.432). In conclusion, vegetarian diets are associated with significant reductions in BP compared with omnivorous diets, suggesting that they may play a key role in the primary prevention and overall management of hypertension.
Topics: Blood Pressure; Diet, Vegetarian; Female; Humans; Hypertension; Male; Randomized Controlled Trials as Topic
PubMed: 32486102
DOI: 10.3390/nu12061604 -
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 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