Cross-sectional and longitudinal comparisons of metabolic profiles between vegetarian and non-vegetarian subjects: a matched cohort study

A Review of Plant-Based Diets for Obesity Management

OBJECTIVE

Obesity is the most prevalent chronic disease in the United States with over 70% of the American population suffering from overweight/obesity. Recently, the popularity of plant-based diets (PBDs) has grown, with individuals adopting these diets for ethical, health and environmental reasons. Our aim is to evaluate the effect of a PBD on weight loss among patients who are overweight or obese.

METHODS

A literature review of PBDs for the treatment of obesity was conducted using PubMed and Scopus. Our search yielded 27 intervention trials (3361 participants) and 6 metanalyses (9168 participants, 61 trials).

RESULTS

Among the intervention trials evaluated, 75% showed a significant increase in weight loss or decrease in weight in the intervention group, on average -5.0 kg (range -1.8 to -12.1 kg). Other outcomes included energy intake (-420 Kcal/d), systolic blood pressure (-3.78 mmHg), fasting plasma glucose (-2.0 mmol/L), hemoglobin A1c (-0.5%, -3.4 mmol/L), total cholesterol (-0.40 mmol/L), low-density lipoprotein (-0.38 mmol/L), triglyceride levels (+0.13 mmol/L), and fiber intake (+10.8 g/d). The 6 meta-analyses showed weight loss (average -2.9 kg, range -2.02 kg to -4.1 kg), body mass index reduction, and improvements in hemoglobin A1c, low-density lipoprotein, and total cholesterol.

CONCLUSION

PBDs result in significant weight loss and improve metabolic outcomes. PBDs offer a sustainable approach to long-term weight loss maintenance. Health care providers should encourage open discussions with their patients regarding their dietary habits to assist them in setting feasible lifestyle goals and consider shared medical appointments to support patients in transitioning to PBDs.

Adherence to a Healthy Diet and Risk of Multiple Carotid Atherosclerosis Subtypes: Insights from the China MJ Health Check-Up Cohort

AIM

Early-stage phenotypes of carotid atherosclerosis (CAS), such as increased carotid intima-media thickness (cIMT), and advanced-stage phenotypes, such as carotid plaque (CP), are at risk for adverse ischemic stroke events. There is limited evidence regarding the causal association between dietary patterns and the risk of CAS in Chinese adults. We therefore examined multiple dietary patterns associated with the risk of CAS and identified the optimal dietary pattern for preventing CAS.

METHODS

We analyzed data collected from the prospective MJ Health Check-up Study (2004-2020), including 13,989 participants 18-80 years of age without CAS. The dietary intake was measured using validated food frequency questionnaires, and dietary pattern scores were calculated for four a priori and four a posteriori dietary patterns. The Cox model was used to estimate the adjusted hazard ratios (HRs) relating various dietary pattern scores to the risk of CAS.

RESULTS

During 43,903.4 person-years of follow-up, 3732 incidents of increased cIMT and 2861 incident CP events were documented. Overall, the seven dietary patterns, except for the high-protein diet, exhibited significant associations with the risk of increased cIMT and CP. Comparing the highest and lowest quartiles, the a posteriori high-fiber dietary pattern (HFIDP) score demonstrated the strongest inverse associations with the risk of increased cIMT (HR 0.65 [95% confidence interval (CI) 0.59-0.71]) and CP (HR 0.65 [95% CI 0.59-0.73]); conversely, another a posteriori high-fat dietary pattern (HFADP; i.e., incorporating high-fat and processed foods) demonstrated the strongest positive associations with the risk of increased cIMT (HR 1.96 [95% CI 1.75-2.20]) and CP (HR 1.83 [95% CI 1.61-2.08]) (all p for trend < 0.01).

CONCLUSIONS

Multiple dietary patterns are significantly associated with the risk of early- and advanced-stage phenotypes of CAS. Notably, a high adherence to an HFIDP and low adherence to an HFADP may confer the greatest risk reduction for CAS.

Gut microbiota in neurological diseases: Melatonin plays an important regulatory role

Melatonin is a highly conserved molecule produced in the human pineal gland as a hormone. It is known for its essential biological effects, such as antioxidant activity, circadian rhythm regulator, and immunomodulatory effects. The gut is one of the primary known sources of melatonin. The gut microbiota helps produce melatonin from tryptophan, and melatonin has been shown to have a beneficial effect on gut barrier function and microbial population. Dysbiosis of the intestinal microbiota is associated with bacterial imbalance and decreased beneficial microbial metabolites, including melatonin. In this way, low melatonin levels may be related to several human diseases. Melatonin has shown both preventive and therapeutic effects against various conditions, including neurological diseases such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This review was aimed to discuss the role of melatonin in the body, and to describe the possible relationship between gut microbiota and melatonin production, as well as the potential therapeutic effects of melatonin on neurological diseases.

Intake of foods high in saturated fats, vegetarian dietary pattern, and sociodemographic characteristics associated with body weight in Peruvian university students

Background

The prevalence of obesity continues to increase among university students and the general population. Consumption of a diet high in saturated fats could be one of the risk factors.

Objective

The consumption of foods high in saturated fats, the vegetarian diet pattern, and sociodemographic characteristics associated with excess body weight (overweight/obesity) were evaluated in Peruvian university students.

Methods

A cross-sectional study was carried out selecting 5,608 Peruvian university students through no probabilistic convenience sampling. The survey was carried out during the months of February and April 2022. The Chi-square test and binary logistic regression analysis were used to evaluate the association between diet (saturated fats intake and dietary pattern) and sociodemographic factors with excess body weight in a cross-sectional analysis.

Results

It was observed that students who reported high consumption of foods high in saturated fats (ORB = 1.14) and those who had a non-vegetarian dietary pattern (ORB = 2.76) were found to be more likely to have excess body weight. On the contrary, students who reported adherence to the vegetarian diet pattern for more than 5 years were less likely to be overweight or obese (ORB = 0.84). Being ≥26 years of age (ORB = 3.28), living in urban areas (ORB = 1.68) and coastal areas of the country (ORB = 1.17), and enrolled in the engineering faculty (ORB = 1.19), were significantly associated with excess body weight.

Conclusion

The findings of the current study evidenced several factors associated with excess body weight in university students. Therefore, it is necessary to promote and implement healthy lifestyle programs, considering sociodemographic and dietary aspects such as age and dietary intake to control and prevent obesity in university students.

Prepregnancy plant-based diets and risk of hypertensive disorders of pregnancy

BACKGROUND

Plant-based diets have been associated with a lower risk of cardiovascular disease in nonpregnant adults, but specific evidence for their effects on risk of hypertensive disorders of pregnancy is scarce.

OBJECTIVE

This study aimed to evaluate the prospective association between adherence to plant-based diets before pregnancy and the risk for hypertensive disorders of pregnancy. We hypothesized that women with higher adherence to plant-based diets would have a lower risk for hypertensive disorders of pregnancy.

STUDY DESIGN

We followed 11,459 parous women (16,780 singleton pregnancies) without chronic diseases, a history of preeclampsia, and cancers who participated in the Nurses' Health Study II (1991-2009), which was a prospective cohort study. Diet was assessed every 4 years using a validated food frequency questionnaire from which we calculated the plant-based diet index (higher score indicates higher adherence) to evaluate the health associations of plant-based diets among participants while accounting for the quality of plant-based foods. Participants self-reported hypertensive disorders of pregnancy, including preeclampsia and gestational hypertension. We estimated the relative risk of hypertensive disorders of pregnancy in relation to plant-based diet index adherence in quintiles using generalized estimating equations log-binomial regression while adjusting for potential confounders and accounting for repeated pregnancies for the same woman.

RESULTS

The mean (standard deviation) age at first in-study pregnancy was 35 (4) years. A total of 1033 cases of hypertensive disorders of pregnancy, including 482 cases of preeclampsia (2.9%) and 551 cases of gestational hypertension (3.3%) were reported. Women in the highest quintile of plant-based diet index were significantly associated with a lower risk for hypertensive disorders of pregnancy than women in the lowest quintile (relative risk, 0.76; 95% confidence interval, 0.62-0.93). There was an inverse dose-response relationship between plant-based diet index and risk for hypertensive disorders of pregnancy. The multivariable-adjusted relative risk (95% confidence interval) of hypertensive disorders of pregnancy for women in increasing quintiles of plant-based diet index were 1 (ref), 0.93 (0.78-1.12), 0.86 (0.72-1.03), 0.84 (0.69-1.03), and 0.76 (0.62-0.93) with a significant linear trend across quintiles (P trend=.005). This association was slightly stronger for gestational hypertension (relative risk, 0.77; 95% confidence interval, 0.60-0.99) than for preeclampsia (relative risk, 0.80; 95% confidence interval, 0.61-1.04). Mediation analysis suggested that body mass index evaluation for dietary assessment and pregnancy explained 39% (95% confidence interval, 15%-70%]) of the relation between plant-based diet index and hypertensive disorders of pregnancy and 48% (95% confidence interval, 12%-86%]) of the relation between plant-based diet index and gestational hypertension.

CONCLUSION

Higher adherence to plant-based diets was associated with a lower risk of developing hypertensive disorders of pregnancy. Much of the benefit seems to be related to improved weight control.

Analysis of adherence to a healthy lifestyle among vegetarian and non-vegetarian Peruvian university students: A cross-sectional survey

BACKGROUND

Evidence shows that a healthy lifestyle can promote physical and mental well-being in the general population. However, there are few studies that assess the adherence to a healthy lifestyle in vegetarian and non-vegetarian university students. The purpose of this study was to evaluate the differences in adherence to a healthy lifestyle between vegetarian and non-vegetarian university students in Peru.

METHODS

A cross-sectional study was carried out considering data from 6,846 students selected by non-probabilistic convenience sampling. The Diet and Healthy Lifestyle Scale (DEVS), the Peruvian validation of the Vegetarian Lifestyle Index (VLI), was used. In addition, sociodemographic and anthropometric data such as weight and height were collected. Body mass index (BMI) was also calculated.

RESULTS

Semi-vegetarian and vegetarian students had a high healthy lifestyle score compared to non-vegetarians. In addition, vegetarian diets showed a significantly higher proportion among students with a lower BMI (normal and underweight). Students with excess body weight (overweight and obesity) were less likely to report healthy lifestyle. In the overall population analyzed, it was observed that the levels of health and lifestyle behaviors, such as daily exercise and sunlight exposure, were mostly moderate and low. Additionally, sweets intake was high, while healthy food consumption such as fruits, vegetables, legumes, and whole grains was low.

CONCLUSION

The current findings show that although vegetarians had better adherence to a healthy lifestyle, interventions in the university setting are needed to improve healthy lifestyle in university students.

The impact of vegetarian diet on sperm quality, sex hormone levels and fertility: a systematic review and meta-analysis

BACKGROUND

An increasing number of people have adhered to a vegetarian diet for several years. Nowadays, the favourable effect of this dietary pattern on metabolic diseases is well established, but its impact on fertility and reproductive health as a serious health concern is not clear yet. Therefore, we aim to summarise existing evidence regarding the possible association between a vegetarian diet and fertility as measured by key indicators such as sperm quality and sex hormone levels.

METHODS

We systematically searched online databases, including PubMed, ISI, Scopus and Google Scholar, up to 1 December 2022 using relevant keywords. We included observational studies that compared semen quality, sex hormone levels and infertility in people who adhered to a vegetarian diet versus an omnivore diet. Heterogeneity between studies was assessed using I2 and Q tests. Standardised mean differences (SMD) using a random/fixed model were calculated to assess outcomes between vegetarians and omnivores in included articles.

RESULTS

Finally, out of 972 documents that were retrieved, 20 articles met our inclusion criteria, and 16 were eligible for quantitative synthesis. Results of meta-analyses showed that there were no significant differences between vegetarians and omnivores in terms of semen quality parameters, including total sperm count, total and progressive sperm motility, sperm morphology and sperm concentration. Seven studies on female sex hormone profiles were eligible for meta-analysis. The only significant difference was the lower level of plasma oestrone in vegetarians (pooled SMD: -0.56; 95% confidence interval [CI]: -1.08, -0.05; p-value = 0.03) compared to omnivores. Furthermore, our meta-analysis revealed significantly higher sex-hormone-binding globulin levels in vegetarian men than in omnivores (pooled SMD: 0.52; 95% CI: 0.18, 0.86; p-value = 0.002).

CONCLUSION

Despite the numerous health benefits of a vegetarian diet, our review suggested that there were no conclusive positive or negative associations between vegetarian diet and semen quality, sex hormone levels and infertility. Further studies are recommended to better understand vegetarian dietary pattern effect on infertility and reproductive health.

Vegan diet: nutritional components, implementation, and effects on adults' health

Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.

A glimpse into plant-based fermented products alternative to animal based products: Formulation, processing, health benefits

Fermented foods and beverages are increasingly being included in the diets of people around the world, as they significantly contribute to flavor and interest in nutrition and food consumption. Plant sources, like cereals and pulses, are employed to produce vegan fermented foods that are either commercially available or the subject of ongoing scientific investigation. In addition, the inclination towards nutritionally healthy, natural, and clean-label products amongst consumers has encouraged the development of vegan fermented products alternative to animal-based products for industrial-scale production. However, as the vegan diet is more restrictive than the vegetarian diet, manufacturing food products for vegans presents a significant problem due to the limited availability of many raw materials. So further research is required on this topic. This paper aims to review the formulation, quality, microbial resources, health benefits, and safety of foods that can be categorised as vegan fermented foods and beverages.

CD36 genetic polymorphism and salivary cues are associated with oleic acid sensitivity and dietary fat intake

There is a lack of research on the combined effects of genetic variations (specifically CD36 SNPs-rs1761667 and rs1527483), dietary food habits (vegetarian or not), and the salivary environment on obesity and taste sensitivity, especially in the Indian population. The current study aims to better understand the relationship between impaired taste perception, fat consumption, higher BMI and obesity development by examining the combined association between CD36 SNPs, oleic acid (OA) detection threshold, and food habits among Indian participants. Furthermore, the relationship between oral fatty acid (FAs) sensitivity and taste physiology factors linked to inflammation and salivary proteins was considered. Participants with the minor allele (AA/AG) of CD36 (in both rs1527483 and rs1761667) consumed more fat, particularly saturated FAs (p = 0.0351). Salivary lipopolysaccharide, which causes inflammation, was significantly greater in non-vegetarians with a higher BMI (p < 0.05), and it exhibited a negative correlation (r = -0.232 and p < 0.05) with Ki67 gene expression, a marker for taste progenitor cells. A positive correlation (r = 0.474, p = 0.04) between TLR4 mRNA levels and the OA detection threshold was also observed. Participants with BMI > 25 kg/m2 had substantially higher TNF-α and IL-6 receptor mRNA expression levels, but there were no significant differences between the vegetarian and non-vegetarian groups. However, salivary CA-VI, which has a buffering capability on the oral environment, was lower in non-vegetarian adults with BMI >25. Thus, it was shown that non-vegetarians with overweight and obesity in India were in at-risk groups for the CD36 SNP (AA/AG at rs1761667 and rs1527483) and had higher levels of inflammatory markers, which exacerbated alterations in food behaviour and physiological changes, indicating their relevance in the development of obesity.

New Insights and Potential Therapeutic Interventions in Metabolic Diseases

Endocrine homeostasis and metabolic diseases have been the subject of extensive research in recent years. The development of new techniques and insights has led to a deeper understanding of the mechanisms underlying these conditions and opened up new avenues for diagnosis and treatment. In this review, we discussed the rise of metabolic diseases, especially in Western countries, the genetical, psychological, and behavioral basis of metabolic diseases, the role of nutrition and physical activity in the development of metabolic diseases, the role of single-cell transcriptomics, gut microbiota, epigenetics, advanced imaging techniques, and cell-based therapies in metabolic diseases. Finally, practical applications derived from this information are made.

Vegetarian diets in Spain: Temporal evolution through national health surveys and their association with healthy lifestyles

OBJECTIVE

To assess the prevalent consumption trend between 2001 and 2017 and the healthy lifestyles associated with consuming a plant-based diet in the Spanish population.

METHODOLOGY

A representative Spanish sample was analysed (>15 years old) from the Spanish National Health Survey for years 2001 (n=8568), 2006 (n=25,649), 2011 (n=19,027) and 2017 (n=21,986). The population was classified as omnivore, vegetarian, or vegan. The lifestyle variables were physical activity, tobacco and alcohol consumption, and body mass index (BMI). The χ2 test was used to evaluate diet change between 2001 and 2017. T-Student and χ2 were used to compare lifestyles of omnivores and vegetarians/vegans. Logistic regression was used to analyse lifestyles associated with plant-based diets.

RESULTS

0.2% of the Spanish population followed a plant-based diet. Between plant-based diet consumers there was an increase in vegans vs. vegetarians between 2001 (9.5% vs. 90.5%) and 2017 (65.3% vs. 34.7%) (p=0.007). Compared to 2001, following a plant-based diet was more likely in 2006 (OR=2.08, p=0.004), 2011 (OR=1.89, p=0.02) and 2017 (OR=1.75, p=0.04). Those who consume alcohol (OR=0.65, p=0.008), who were overweight (OR=0.48, p<0.001) or who were obese (OR=0.40, p=0.001) were less likely to consume a plant-based diet.

CONCLUSIONS

Despite an increase in the consumption of plant-based diets between 2001 and 2017, there was a low prevalence of consumption in all years studied. There was a greater probability of consuming plant-based diets among the Spanish population with healthy behaviours. These findings could help design strategies focused on healthy nutritional behaviours.

The Role of Dietary Potassium in the Cardiovascular Protective Effects of Plant-Based Diets

Dietary intervention is an essential factor in managing a multitude of chronic health conditions such as cardiovascular and chronic kidney disease. In recent decades, there has been a host of research suggesting the potential benefit of plant-based diets in mitigating the health outcomes of these conditions. Plant-based diets are rich in vegetables and fruits, while limiting processed food and animal protein sources. The underlying physiological mechanism involves the interaction of several macronutrients and micronutrients such as plant protein, carbohydrates, and dietary potassium. Specifically, plant-based foods rich in potassium provide cardiorenal protective effects to include urinary alkalization and increased sodium excretion. These diets induce adaptive physiologic responses that improve kidney and cardiovascular hemodynamics and improve overall metabolic health. A shift toward consuming plant-based diets even in subjects with cardiorenal decrements may reduce their morbidity and mortality. Nonetheless, randomized controlled trials are needed to confirm the clinical benefits of plant-based diets.

Cardiovascular Mortality, Habitual Exercise, and Particulate Matter 2.5 Exposure: A Longitudinal Cohort Study

INTRODUCTION

Habitual exercise may amplify the respiratory uptake of air pollutants in the lung, exacerbating the adverse effects of air pollution. However, it is unclear whether this can reduce the health benefits of habitual exercise (referred to as leisure-time exercise). Thus, the combined effects of habitual exercise and chronic exposure to ambient fine particulate matter 2.5 on cardiovascular mortality were examined among adults in Taiwan.

METHODS

A total of 384,128 adults were recruited between 2001 and 2016 and followed up to May 31, 2019. Participants' vital status was obtained by matching their unique identification numbers with records of cardiovascular death in the National Death Registry of Taiwan. A time-varying Cox regression model was used to analyze the data. Analyses were conducted in 2021.

RESULTS

Cardiovascular death risks were inversely associated with habitual exercise and positively associated with chronic exposure to particulate matter 2.5. The beneficial effects of habitual exercise on cardiovascular mortality were not modified by chronic exposure to particulate matter 2.5. Inactive participants with high particulate matter 2.5 exposure exhibited a 123% higher risk of cardiovascular death than high-exercise-group participants exposed to low levels of particulate matter 2.5 (95% CI=89, 163).

CONCLUSIONS

High level of habitual exercise combined with low exposure level of ambient particulate matter 2.5 is associated with the lowest risk of cardiovascular death. A higher level of habitual exercise is associated with a lower risk of cardiovascular death at all levels of particulate matter 2.5 exposure studied. The results indicate that habitual exercise is a safe health promotion strategy even for people residing in relatively polluted regions.

Vegetarian and vegan diets and the risk of cardiovascular disease, ischemic heart disease and stroke: a systematic review and meta-analysis of prospective cohort studies

PURPOSE

Vegetarian diets have been associated with reduced risk of ischemic heart disease (IHD). However, results regarding cardiovascular disease (CVD) overall and stroke are less clear. We conducted a systematic review and meta-analysis of prospective cohort studies on CVD, IHD and stroke risk among vegetarians or vegans versus nonvegetarians to clarify these associations.

METHODS

PubMed and Ovid Embase databases were searched through August 12, 2021. Prospective cohort studies reporting adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for incidence or mortality from CVD, IHD and stroke, comparing vegetarians and vegans to nonvegetarians were included. Risk of bias (RoB) was assessed using ROBINS-I and the strength of evidence was assessed using World Cancer Research Fund (WCRF) criteria. Summary RRs (95% CIs) were estimated using a random effects model.

RESULTS

Thirteen cohort studies (844,175 participants, 115,392 CVD, 30,377 IHD, and 14,419 stroke cases) were included. The summary RR for vegetarians vs. nonvegetarians was 0.85 (95% CI: 0.79-0.92, I² = 68%, n = 8) for CVD, 0.79 (95% CI: 0.71-0.88, I² = 67%, n = 8) for IHD, 0.90 (95% CI: 0.77-1.05, I² = 61%, n = 12) for total stroke, and for vegans vs. nonvegetarians was 0.82 (95% CI: 0.68-1.00, I² = 0%, n = 6) for IHD. RoB was moderate (n = 8) to serious (n = 5). The associations between vegetarian diets and CVD and IHD were considered probably causal using WCRF criteria.

CONCLUSIONS

Vegetarian diets are associated with reduced risk of CVD and IHD, but not stroke, but further studies are needed on stroke. These findings should be considered in dietary guidelines.

REVIEW REGISTRATION

No review protocol registered.

Healthy plant-based diets improve dyslipidemias, insulin resistance, and inflammation in metabolic syndrome. A narrative review

Plant-based diets (PBDs) have become very popular in recent years and have been identified as a dietary strategy associated with protection against chronic disease. However, the classifications of PBDs vary depending on the type of diet. Some PBDs have been recognized as healthful for their high content of vitamins, minerals, antioxidants, and fiber, or unhealthful if they are high in simple sugars and saturated fat. Depending on this classification, the type of PBD impacts its protective effects against disease dramatically. Metabolic syndrome (MetS), characterized by the presence of high plasma triglycerides and low HDL cholesterol, impaired glucose metabolism, elevated blood pressure, and increased concentrations of inflammatory biomarkers, also increases the risk for heart disease and diabetes. Thus, healthful plant-based diets could be considered favorable for individuals having MetS. The different types of plant-based diets (vegan, lacto-vegetarian, lacto-ovo-vegetarian, or pescatarian) are discussed with a focus on specific effects of dietary components in maintaining a healthy weight, protecting against dyslipidemias, insulin resistance, hypertension, and low-grade inflammation.

Plant-Based Diets and Lipid, Lipoprotein, and Inflammatory Biomarkers of Cardiovascular Disease: A Review of Observational and Interventional Studies

Plant-based diets (PBDs) are becoming increasingly popular. Thus far, the literature has focused on their association with lipid profiles, with less investigation of lipoprotein and inflammatory profiles. Because pro-atherogenic lipid, lipoprotein, and inflammatory processes may facilitate the development of atherosclerosis, understanding the relation between PBDs and these processes is important to inform risk mitigation strategies. Therefore, the objective of this paper was to review the literature on PBDs and lipid, lipoprotein, and inflammatory biomarkers of cardiovascular disease (CVD). A structured literature search was performed, retrieving 752 records, of which 43 articles were included. Plant-based diets generally associated with favourable lipid and lipoprotein profiles, characterised by decreased total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B concentrations, and less low-grade inflammation, characterised by decreased C-reactive protein concentrations. Effect sizes from PBD interventions were greatest compared to habitual dietary patterns, and for non-low-fat vegan and tightly controlled dietary interventions. Associations between PBD indices and the reviewed biomarkers were less consistent. Findings are discussed with reference to the literature on PBDs and PBD indices and CVD risk, the associations between specific plant food groups and CVD outcomes and the reviewed biomarker outcomes, and the potential mechanisms underpinning associations between PBDs and reduced CVD risk.

Retrospective assessment of metabolic syndrome components in early adult life on vegetarian dietary status

Background

Metabolic syndrome (MetS) encompasses several clinical presentations that include truncal obesity and insulin resistance at its core. MetS afflicts 23% of the adult US population, increasing their risk of diabetes and cardiovascular disease. Many studies have indicated the importance of a vegetarian diet in improving overall health and more specifically MetS components. Unfortunately, these findings have been inconsistent and cannot be extended to examine effects on MetS incidence in the younger adult population.

Objective

This study aimed to conduct a retrospective analysis of a vegetarian vs. non-vegetarian dietary status in young adults (age 18-24) based on MetS components in later adulthood (age 20-30). This study focuses on elucidating any relationship between a vegetarian diet and MetS components of central obesity, hypertension, and hyperlipidemia. Methods: Waves 3 and 4 data were acquired from AddHealth. One-to-one propensity score matched vegetarians to non-vegetarians in a cohort of 535 women and 159 men. Logistical regression assessed the relationship between vegetarian status and MetS components, including truncal obesity (cm), hypertension (normal, pre-HT, HT1, and HT2), and hyperlipidemia (high and low). Results MetS components from ages 20 to 30 are not associated with vegetarian dietary status. Truncal obesity [N = 694; M = 92.82 cm; OR 0.999; p = 0.893; 95% CI (0.980, 1.017)]; hypertension [N = 694; OR 0.949; p = 0.638; 95% CI (0.764, 1.179)]; hyperlipidemia [N = 694; OR 0.840; p = 0.581; 95% CI (0.453, 1.559)].

Conclusion

Current study results were consistent with previous findings suggesting that consumption of a vegetarian diet cannot be directly linked to MetS outcomes. However, further investigation should be completed as MetS is a risk factor for several chronic diseases.

The toxic effects of endocrine disrupting chemicals (EDCs) on gut microbiota: Bisphenol A (BPA). A review

BACKGROUND

Bisphenol A (BPA), an important industrial material widely applied in daily products, is considered an endocrine-disrupting chemical that may adversely affect humans. Growing evidence have shown that intestinal bacterial alterations caused by BPA exposure play an important role in several local and systemic diseases.

AIM OF THE STUDY

finding evidence that BPA-induced alterations in gut microbiota composition and activity may perturb its role on human health.

RESULTS

evidence from several experimental settings show that both low and high doses of BPA, interfere with the hormonal, homeostatic and reproductive systems in both animals and human systems. Moreover, it has recently been classified as an environmental obesogenic, with metabolic-disrupting effects on lipid metabolism and pancreatic b-cell functions. Several evidence characterize PBA as an environmental contributor to type II diabetes, metabolic syndrome, and obesity. However, the highest estimates of the exposure derived from foods alone or in combination with other sources are 3 to 5 times below the new tolerable daily intake (TDI) value, today reduced by the European Food Safety Authority (EFSA) experts from 50 micrograms per kilogramme of bodyweight per day (µg/kg bw/day) to 4 µg/kg bw/day.

CONCLUSIONS

Considering estimates for the total amount of BPA that can be ingested daily over a lifetime, many International Health Authorities conclude that dietary exposure of adult humans to BPA does not represent a risk to consumers' health, declaring its safety due to very-low established levels in food and water and declare any appreciable health risk.

Dietary Regimen, Overweight, and Obesity in Human Nutrition Students and Other Majors: A Cross-Sectional Study

Background

Choosing a healthy diet is an increasingly a challenge for university students. The objective of this study was to compare diet and overweight/obesity in human nutrition students (HNS) and students of other careers (SOC) from a university located in Lima, Peru.

Methods

It was a cross-sectional study consisting of 158 students out of an initial sample of 170. Information was collected on the sociodemographic and anthropometric characteristics of the participants and a validated questionnaire was applied to evaluate the frequency of food consumption.

Results

There was no significant difference in diet between HNS and SOC (p > 0.05). HNS most frequently consumed yellow/orange vegetables (p = 0.020), purple vegetables (p = 0.049), citrus fruits (p = 0.029), eggs (p = 0.002), whole milk (p = 0.013), yogurt (p = 0.017), tofu (p = 0.003), olive oil (p = 0.003), other vegetable oils (p < 0.001), and alcoholic beverages (p = 0.037) than SOC. In contrast, HNS had a lower frequency of nonfried tuber intake (p = 0.039), fried tubers (p < 0.001), milk desserts (p = 0.048), flour fritters (p = 0.027), cookies with chocolate (p = 0.050), croissants (p = 0.030), cookies with filling (p = 0.024), candies (p = 0.006), and soda (p = 0.016) than SOC. Overweight/obesity was not different between HNS and SOC (p > 0.05).

Conclusions

This study found significant differences in the consumption of some foods between HNS and SOC. However, it found no significant difference in diet and overweight/obesity between HNS and SOC.

Association Between Ideal Cardiovascular Health and Vegetarian Dietary Patterns Among Community-Dwelling Individuals

Background

Vegetarians have been shown to have better metabolic profiles than non-vegetarians, and vegetarianism has potential beneficial effects on cardiovascular disease. However, there is a lack of studies on vegetarians that examine both metabolic profiles and lifestyle habits, such as physical activity, smoking habits, and dietary patterns, which are equally important in the context of cardiovascular disease. We explored whether a vegetarian diet is associated with both metabolic traits and lifestyle habits by assessing cardiovascular health (CVH) metrics.

Methods

This was a cross-sectional study conducted in a Taiwanese population. Data collected between 2000 and 2016 were extracted from the MJ Health database. Participants aged 40 years and older without cardiovascular disease were included. CVH metrics included smoking habits, blood pressure, total cholesterol, serum glucose, body mass index, physical activity, and healthy diet score. Vegetarian participants were full-time vegetarians who did not consume meat or fish. All the data were assessed from self-report questionnaires, physical examinations, and blood analyses following standard protocol. Multiple logistic regression analysis was used to evaluate the association between vegetarianism and CVH metrics.

Results

Of 46,287 eligible participants, 1,896 (4.1%) were vegetarian. Overall, vegetarians had better CVH metrics (OR = 2.09, 95% CI = 1.84–2.37) but lower healthy diet scores (OR = 0.41, 95% CI = 0.33–0.51) after adjustment. No difference in physical activity (OR = 0.86, 95% CI = 0.73–1.02) was identified between vegetarians and non-vegetarians. Additionally, vegetarians had higher whole grain intake (OR = 2.76, 95% CI = 2.28–3.35) and lower sugar-sweetened beverage consumption (OR = 1.36, 95% CI = 1.18–1.58).

Conclusions

Our results suggested that vegetarians had better overall ideal CVH metrics but lower ideal healthy diet scores than non-vegetarians, which was likely due to the lack of fish consumption in this population group. When assessing CVH metrics and healthy diet scores for vegetarians, metrics and scores chosen should be suitable for use with vegetarian populations.

Genistein protects against ultraviolet B-induced wrinkling and photoinflammation in in vitro and in vivo models

Background

Chronic exposure to ultraviolet (UV) rays causes severe skin damage by inducing oxidative stress and inflammation. Identifying a safe and natural substance for skin protection is a crucial research goal.

Objective

The aim of this study was to clarify the effects of genistein on skin inflammation and photoaging by using 3 models (humans: skin parameters; animals: wrinkle formation; and cells: anti-inflammatory effects).

Methods

Food frequency questionnaire data and serum and skin parameter data from 120 volunteers (a group with a genistein-rich diet [RG group] and a control group). Human keratinocytes were pretreated with genistein before ultraviolet B (UVB) irradiation. Genistein was topically applied to the dorsal skin of rats.

Results

The blood samples of the RG group had lower serum uric acid levels and blood urea nitrogen levels. The dynamic elasticity level in the RG group was higher than that in the controls. Genistein pretreatment suppressed the expression of proinflammatory cytokines (CXCL1, IL-1, MIF, and PLANH1) and the proteins released by UVB-treated keratinocytes. Topical application of genistein to the dorsal skin of rats reduced the severity of UVB-induced wrinkling. Both intake and topical application of genistein combated UVB-induced inflammation and aging.

Conclusions

Genistein could be used as a safe and natural compound for use in novel anti-inflammatory agents for topical application.

Graphical abstract

The experimental design procedure, including the skin parameter and blood serum measurements of 137 participants. Genistein-rich compounds provide protection against UVB-induced inflammation, as determined using in vitro and in vivo animal model experiments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-022-00706-x.

Post-diagnostic reliance on plant-compared with animal-based foods and all-cause mortality in omnivorous long-term colorectal cancer survivors

BACKGROUND

Plant-rich diets are associated with lower cardiometabolic risks and longer survival in the general population, but their association with mortality in cancer survivors is still unclear.

OBJECTIVES

We aimed to examine the associations of 3 postdiagnostic plant-based diet indices with all-cause mortality in omnivorous long-term colorectal cancer (CRC) survivors.

METHODS

Diet was assessed with FFQs at a median of 6 years after diagnosis in 1404 CRC survivors (56% male; median age, 69 years) in a Northern German prospective cohort study. An overall, a healthful plant-based, and an unhealthful plant-based diet index were derived by scoring intakes of animal foods reversely and intakes of healthy (whole grains, vegetables, fruits, legumes, nuts, oils, tea/coffee) and less healthy plant foods (refined grains, fruit juices, sugar-sweetened beverages, potatoes, sweets/desserts) positively or reversely, depending on the index. Vital status follow-up was conducted via population registries. Cox proportional hazards regression was applied to estimate HRs for all-cause mortality according to plant-based diet adherence.

RESULTS

Within 7 years (median) after diet assessment, 204 deaths occurred. The overall plant-based diet index displayed a significant, inverse association with all-cause mortality (HR per 10-point increase in diet index, 0.72; 95% CI, 0.57-0.91). Although not statistically significant, higher healthful plant-based diet scores showed a strong tendency towards lower mortality (HR, 0.82; 95% CI, 0.67-1.01). The unhealthful plant-based diet index was associated with higher mortality, but lost statistical significance after multivariable adjustment (HR, 1.19; 95% CI, 0.96-1.48). A subgroup analysis revealed that the tendency towards a positive association of the unhealthful plant-based diet with mortality was restricted to less physically active individuals (<95 metabolic equivalent of task hours/week).

CONCLUSIONS

An overall plant-based diet was inversely associated with all-cause mortality in long-term CRC survivors. However, more research is needed to further disentangle the impacts of different qualities of plant-based diets on cancer survivors' health.

Perspective: Low Risk of Parkinson's Disease in Quasi-Vegan Cultures May Reflect GCN2-Mediated Upregulation of Parkin

Mitochondrial dysfunction in dopaminergic neurons of the substantia nigra (SN) appears to be a key mediating feature of Parkinson's disease (PD), a complex neurodegenerative disorder of still unknown etiology. Parkin is an E3 ubiquitin ligase that promotes mitophagy of damaged depolarized mitochondria while also boosting mitochondrial biogenesis-thereby helping to maintain efficient mitochondrial function. Boosting Parkin expression in the SN with viral vectors is protective in multiple rodent models of PD. Conversely, homozygosity for inactivating mutations of Parkin results in early-onset PD. Moderate protein plant-based diets relatively low in certain essential amino acids have the potential to boost Parkin expression by activating the kinase GCN2, which in turn boosts the expression of ATF4, a factor that drives transcription of the Parkin gene. Protein-restricted diets also upregulate the expression of PINK1, a protein that binds to the outer membrane of depolarized mitochondria and then recruits and activates Parkin. This effect of protein restriction is mediated by the downregulation of the kinase activity of mammalian target of rapamycin complex 1; the latter suppresses PINK1 expression at the transcriptional level. During the 20th century, cultures in East Asia and sub-Sahara Africa consuming quasi-vegan diets were found to be at notably decreased risk of PD compared with the USA or Europe. It is proposed that such diets may provide protection from PD by boosting Parkin and PINK1 expression in the SN. Other measures that might be expected to upregulate protective mitophagy include supplemental N-acetylcysteine (precursor for hydrogen sulfide) and a diet rich in spermidine-a polyamine notably high in corn.

Foods for Plant-Based Diets: Challenges and Innovations

Plant-based diets have become popular as a means of reducing the environmental footprint of the diet and promoting human health and animal welfare. Although the percentages of vegetarians and vegans are low compared to omnivores, their numbers have increased significantly in the last years. The use of non-animal food products other than meat alternatives is also increasing and this tendency constitutes an opportunity for the food industry. In this review, we present that plant-based meat and milk alternatives are consolidated but that there is a niche for egg, seafood alternatives, and new products which may not resemble any traditional animal food. However, not all animal food substitutes are sustainable and some of them are even ultra-processed. In addition, there are concerns on safety and labeling, and consumers demand clear information and regulation. The challenges in this field are connected with food design and technology, sensory science, nutrition, and dietetics. Moreover, adequate selection and combination of foods is important in order to achieve consumer acceptance while preventing nutritional deficiencies in those who choose this type of diet.

Metabolic Physiological Networks: The Impact of Age

Metabolic homeostasis emerges from the interplay between several feedback systems that regulate the physiological variables related to energy expenditure and energy availability, maintaining them within a certain range. Although it is well known how each individual physiological system functions, there is little research focused on how the integration and adjustment of multiple systems results in the generation of metabolic health. The aim here was to generate an integrative model of metabolism, seen as a physiological network, and study how it changes across the human lifespan. We used data from a transverse, community-based study of an ethnically and educationally diverse sample of 2572 adults. Each participant answered an extensive questionnaire and underwent anthropometric measurements (height, weight, and waist), fasting blood tests (glucose, HbA1c, basal insulin, cholesterol HDL, LDL, triglycerides, uric acid, urea, and creatinine), along with vital signs (axillar temperature, systolic, and diastolic blood pressure). The sample was divided into 6 groups of increasing age, beginning with less than 25 years and increasing by decades up to more than 65 years. In order to model metabolic homeostasis as a network, we used these 15 physiological variables as nodes and modeled the links between them, either as a continuous association of those variables, or as a dichotomic association of their corresponding pathological states. Weight and overweight emerged as the most influential nodes in both types of networks, while high betweenness parameters, such as triglycerides, uric acid and insulin, were shown to act as gatekeepers between the affected physiological systems. As age increases, the loss of metabolic homeostasis is revealed by changes in the network’s topology that reflect changes in the system−wide interactions that, in turn, expose underlying health stages. Hence, specific structural properties of the network, such as weighted transitivity, i.e., the density of triangles in the network, can provide topological indicators of health that assess the whole state of the system. Overall, our findings show the importance of visualizing health as a network of organs and/or systems, and highlight the importance of triglycerides, insulin, uric acid and glucose as key biomarkers in the prevention of the development of metabolic disorders.

Changes in biochemical parameters by gender and time: Effect of short-term vegan diet adherence

Background

Vegetarian diets adapted for various reasons that may include religious, ethical, and health considerations have reasonable health benefits including weight loss, and favorable metabolic changes. However, studies that assessed health benefits associated with vegan diet practices during the Ethiopian Orthodox Christian (EOC) Lenten fasting remains limited. This study has, therefore, assessed how short-term vegan diet associated with metabolic traits, including weight, body mass index (BMI), circumference, blood pressure, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), through longitudinal cross-sectional study design.

Methods

Seventy-five subjects (34 females and 41 males) with a mean age of [+SD] 27.3 + 5.8 years (range, 18 and 35) took part in the study. The study followed three assessment sessions: at baseline, during the Lenten (week 7), and 7 weeks after the end of the Lenten (week 14). An automatic chemistry analyzer (Mindray, BE-2000, China) used for lipid profile analysis. We used paired sample t-test in pre and post-performance and repeated measures ANOVA with Bonferroni post hoc adjustment between time points. The statistical significance was set at p < 0.05.

Results

The EOC fasting with vegan diet induced significantly lower blood pressure, weight, BMI, TC, HDL-C, LDL-C, and TC: HDL-C ratios, during Lenten (that is vegan diet consumption), but a regain noted in these parameters 7-weeks after Lenten (that is omnivore diet). On gender differences, vegan diet associated with significantly lower blood pressure, TC, and LDL-C in females compared with age-matched male counterparts. Some methodological limitations of this study are discussed with particular reference to lack of a randomized control group and self-reported data that limit this study in establishing a causal relationship through observed associations.

Conclusions

Vegan diet consumption even for short period corroborate ideal metabolic traits, with more favorable changes noted in women than age-matched men counterparts. These findings might help to define vegetarian diets as part of religious fasting (beyond its spiritual goals) as a non-pharmacological prescription in different populations, and our findings add to growing evidence in these subjects.

The associations of plant-based protein intake with all-cause and cardiovascular mortality in patients on peritoneal dialysis

BACKGROUND AND AIMS

Plant-based protein intake is associated with all-cause and/or cardiovascular disease (CVD) mortality in general population, but such data are scarce in dialysis patients. Thus, we examined the associations of plant-based protein-total protein ratio with all-cause and CVD mortality in patients on peritoneal dialysis (PD).

METHODS AND RESULTS

The study enrolled 884 incident patients who started PD between October 2002 and August 2014. All demographic and laboratory data were recorded at baseline. Repeated measurements for laboratory and nutrition parameters were recorded at regular intervals and thus calculated as time-averaged values. Multivariable Cox regression models were used to estimate the hazard ratio (HR) of plant-based protein-total protein ratio and mortality based on baseline and time-averaged covariates, respectively. There were 437 (49%) patients died during a mean follow-up period of 45 months, of which 178 (40.8%) were due to CVD. Each 10% in increase in time-averaged plant-based protein-total protein ratio was associated with a reduction of 71% (95% CI, 90%-14%) and 89% (95% CI, 98%-29%) for all-cause and CVD mortality, respectively. Based on examination on interactive effects, we further found both baseline and time-averaged plant-based protein-total protein ratio were inversely associated with all-cause and CVD mortality in the subgroups of female, age ≥60 years, and albumin >35 g/L.

CONCLUSIONS

The present study suggested that a diet with a higher plant-based protein-total protein ratio is associated with lower all-cause and CVD mortality in PD patients, and is more significant in female and elderly patients, and those without hypoalbuminemia.

Vegetarian, pescatarian and flexitarian diets: sociodemographic determinants and association with cardiovascular risk factors in a Swiss urban population

Prevalence and trends of different vegetarian diets remain unknown, with estimates varying depending on the source. Evidence suggests that vegetarian diets are associated with a more favourable cardiovascular risk profile. The present study aimed to assess the prevalence and trends of different types of vegetarian diets in a population-based representative sample, sociodemographic characteristics of participants following such diets and the association of these diets with cardiovascular risk factors. Using repeated cross-sectional population-based surveys conducted in Geneva, Switzerland, 10 797 individuals participated in the study between 2005 and 2017. Participants were classified as vegetarians, pescatarians, flexitarians or omnivores using an FFQ. Sociodemographic and cardiovascular risk factors were evaluated through questionnaires, anthropometric measurements and blood tests. Findings show prevalence of vegetarians increased from 0·5 to 1·2 %, pescatarians from 0·3 to 1·1 % and flexitarians remained stable at 15·6 % of the population over the study period. Compared with omnivores, vegetarians were more likely to be young (OR 2·38; 95 % CI 1·01, 5·6), have higher education (OR 1·59; 95 % CI 1·01, 2·49) and lower income (OR 1·83; 95 % CI 1·04, 3·21); pescatarians and flexitarians were more likely to be women (pescatarian: OR 1·81; 95 % CI 1·10, 3·00; vegetarian: OR 1·57; 95 % CI 1·41, 1·75) and flexitarians were also more likely to have a lower income (OR 1·31; 95 % CI 1·13, 1·53). Participants who adhered to any diet excluding/reducing meat intake had lower BMI, total cholesterol and hypertension compared with omnivores. The present study shows an increase in the prevalence of vegetarians over a 13-year period and suggests that the different vegetarian diets assessed are associated with a better cardiovascular risk profile.

Effects of Living High-Training Low and High on Body Composition and Metabolic Risk Markers in Overweight and Obese Females

This study examined the effects of 4 weeks of living high-training low and high (LHTLH) under moderate hypoxia on body weight, body composition, and metabolic risk markers of overweight and obese females. Nineteen healthy overweight or obese females participated in this study. Participants were assigned to the normoxic training group (NG) or the LHTLH group (HG). The NG participants lived and trained at sea level. The HG participants stayed for approximately 10 hours in a simulated 2300 m normobaric state of hypoxia for six days a week and trained for 2 hours 3 times a week under the same simulated hypoxia. The interventions lasted for 4 weeks. All groups underwent dietary restriction based on resting metabolic rate. The heart rate of the participants was monitored every ten minutes during exercise to ensure that the intensity was in the aerobic range. Compared with the preintervention values, body weight decreased significantly in both the NG and the HG (−8.81 ± 2.09% and −9.09 ± 1.15%, respectively). The fat mass of the arm, leg, trunk, and whole body showed significant reductions in both the NG and the HG, but no significant interaction effect was observed. The percentage of lean soft tissue mass loss in the total body weight loss tended to be lower in the HG (27.61% versus 15.94%, P=0.085). Between the NG and the HG, significant interaction effects of serum total cholesterol (−12.66 ± 9.09% versus −0.05 ± 13.36%,) and apolipoprotein A₁ (−13.66 ± 3.61% versus −5.32 ± 11.07%, P=0.042) were observed. A slight increase in serum high-density lipoprotein cholesterol (HDL-C) was observed in the HG (1.12 ± 12.34%) but a decrease was observed in the NG (−11.36 ± 18.91%). The interaction effect of HDL-C between NG and HG exhibited a significant trend (P=0.055). No added effects on serum triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), or APO-B were observed after 4 weeks of LHTLH. In conclusion, 4 weeks of LHTLH combined with dietary restriction could effectively reduce the body weight and body fat mass of overweight and obese females. Compared with training and sleeping under normoxia, no additive benefit of LHTLH on the loss of body weight and body fat mass was exhibited. However, LHTLH may help to relieve the loss of lean soft tissue mass and serum HDL-C.

Vegetarian diets and chronic kidney disease

While dietary restriction of protein intake has long been proposed as a possible kidney-protective treatment, the effects of changes in the quality of ingested proteins on the prevalence and risk of progression of chronic kidney disease (CKD) have been scarcely studied; these two aspects are reviewed in the present article. The prevalence of hypertension, type 2 diabetes and metabolic syndrome, which are the main causes of CKD in Western countries, is lower in vegetarian populations. Moreover, there is a negative relationship between several components of plant-based diets and numerous factors related to CKD progression such as uraemic toxins, inflammation, oxidative stress, metabolic acidosis, phosphate load and insulin resistance. In fact, results from different studies seem to confirm a kidney-protective effect of plant-based diets in the primary prevention of CKD and the secondary prevention of CKD progression. Various studies have determined the nutritional safety of plant-based diets in CKD patients, despite the combination of a more or less severe dietary protein restriction. As observed in the healthy population, this dietary pattern is associated with a reduced risk of all-cause mortality in CKD patients. We propose that plant-based diets should be included as part of the clinical recommendations for both the prevention and management of CKD.

Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study

OBJECTIVE

To examine the associations of vegetarianism with risks of ischaemic heart disease and stroke.

DESIGN

Prospective cohort study.

SETTING

The EPIC-Oxford study, a cohort in the United Kingdom with a large proportion of non-meat eaters, recruited across the country between 1993 and 2001.

PARTICIPANTS

48 188 participants with no history of ischaemic heart disease, stroke, or angina (or cardiovascular disease) were classified into three distinct diet groups: meat eaters (participants who consumed meat, regardless of whether they consumed fish, dairy, or eggs; n=24 428), fish eaters (consumed fish but no meat; n=7506), and vegetarians including vegans (n=16 254), based on dietary information collected at baseline, and subsequently around 2010 (n=28 364).

MAIN OUTCOME MEASURES

Incident cases of ischaemic heart disease and stroke (including ischaemic and haemorrhagic types) identified through record linkage until 2016.

RESULTS

Over 18.1 years of follow-up, 2820 cases of ischaemic heart disease and 1072 cases of total stroke (519 ischaemic stroke and 300 haemorrhagic stroke) were recorded. After adjusting for sociodemographic and lifestyle confounders, fish eaters and vegetarians had 13% (hazard ratio 0.87, 95% confidence interval 0.77 to 0.99) and 22% (0.78, 0.70 to 0.87) lower rates of ischaemic heart disease than meat eaters, respectively (P<0.001 for heterogeneity). This difference was equivalent to 10 fewer cases of ischaemic heart disease (95% confidence interval 6.7 to 13.1 fewer) in vegetarians than in meat eaters per 1000 population over 10 years. The associations for ischaemic heart disease were partly attenuated after adjustment for self reported high blood cholesterol, high blood pressure, diabetes, and body mass index (hazard ratio 0.90, 95% confidence interval 0.81 to 1.00 in vegetarians with all adjustments). By contrast, vegetarians had 20% higher rates of total stroke (hazard ratio 1.20, 95% confidence interval 1.02 to 1.40) than meat eaters, equivalent to three more cases of total stroke (95% confidence interval 0.8 to 5.4 more) per 1000 population over 10 years, mostly due to a higher rate of haemorrhagic stroke. The associations for stroke did not attenuate after further adjustment of disease risk factors.

CONCLUSIONS

In this prospective cohort in the UK, fish eaters and vegetarians had lower rates of ischaemic heart disease than meat eaters, although vegetarians had higher rates of haemorrhagic and total stroke.

Changes in intake of plant-based diets and weight change: results from 3 prospective cohort studies

BACKGROUND

Studies have found beneficial effects of plant-based diets on weight. However, not all plant foods are necessarily beneficial.

OBJECTIVES

The aim of this study was to examine associations of changes in intake of 3 variations of plant-based diet indices (overall, healthful, and unhealthful) with weight change over 4-y intervals spanning >20 y.

METHODS

Data from 3 ongoing prospective observational cohort studies in the United States were used, namely the Nurses' Health Study (NHS), NHS2, and the Health Professionals Follow-up Study (HPFS), with 126,982 adult men and women. Self-reported diet data were collected every 4 y, and self-reported weight data were used to compute weight change every 4 y over >20 y of follow-up.

RESULTS

On average, participants gained a mean of 0.90 kg (HPFS) to 1.98 kg (NHS2) over 4-y intervals. Different types of plant-based diet indices were associated with different amounts of weight gain. After adjusting for several potential confounders, including concomitant changes in other lifestyle factors, a 1-SD increase in intake of an overall plant-based diet index was associated with 0.04 kg less weight gain over 4-y periods (95% CI: 0.05, 0.02 kg; P < 0.001). A 1-SD increase in intake of a healthful version of a plant-based diet index (emphasizing whole grains, fruits/vegetables, nuts/legumes, vegetable oils, tea/coffee) was associated with 0.68 kg less weight gain over 4-y periods (95% CI: 0.69, 0.66 kg; P < 0.001). Conversely, a 1-SD increase in an unhealthful version of a plant-based diet index (emphasizing refined grains, potato/fries, sweets, sweetened drinks/juices) was associated with 0.36 kg more weight gain (95% CI: 0.34, 0.37 kg, P < 0.001).

CONCLUSION

Plant-based diets, especially when rich in healthier plant foods, are associated with less weight gain over 4-y intervals. This supports current recommendations to increase intake of healthy plant foods, and reducing intake of less-healthy plant foods and animal foods, for improved health outcomes.

Health Biomarkers in Adults Are More Closely Linked to Diet Quality Attributes Than to Plant-Based Diet Categorization

Although plant-based diets are promoted for healthy outcomes, these diets are not synonymous with high-quality diets. Plant-based diets can include highly processed, less healthful foods, including savory snacks, pastries, and sugary fruit drinks. This cross-sectional study examined the diet quality of vegetarian and omnivorous adults, matched for gender, age, and adiposity, and related diet quality to standard health biomarkers. Diet quality was assessed using the Rapid Eating and Activity Assessment for Participants Short Version questionnaire. Participants (17 vegetarians and 16 omnivores; 28.2 ± 8.9 years; 22.5 ± 2.7 kg/m²) were non-smokers and healthy by self-report. The median duration of adherence to the vegetarian diet was 27 months. Physical activity level and diet quality did not differ significantly between diet groups. Moreover, health biomarkers did not differ by diet groups. When participants were regrouped by low versus high diet quality, health biomarkers differed significantly between groups for fasting insulin, HOMA-IR, triglyceride (TG)/HDL ratio, and blood folate, with more favorable levels in the group with high diet quality. These data suggest that health biomarkers more closely align with diet quality attributes than with plant-based diet categorization. Thus, messaging focused on healthy diet attributes may lead to better health outcomes than the simple promotion of plant-based diets.

Effect of vegetarian diets on the presentation of metabolic syndrome or its components: A systematic review and meta-analysis

BACKGROUND & AIMS

Several studies have examined the effect of vegetarian diets (VD) on metabolic syndrome (MetS) or its components, but findings have been inconsistent. The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies to assess the association between VD and MetS or its components (systolic blood pressure [SBP], diastolic blood pressure [DBP], fasting glucose triglycerides, waist circumference [WC], HDL-cholesterol (HDL-C)) in adults.

METHODS

The Cochrane Library, EMBASE, PubMed, Web of Science, and Scopus were searched. RCTs, cohort studies and cross-sectional studies evaluating the effects of VD on MetS or its components in adults, with omnivore diet as control group, were included. Random effects meta-analyses stratified by study design were employed to calculate pooled estimates.

RESULTS

A total of 71 studies (n = 103 008) met the inclusion criteria (6 RCTs, 2 cohorts, 63 cross-sectional). VD were not associated with MetS in comparison to omnivorous diet (OR 0.96, 95% CI 0.50-1.85, p = 0.9) according to meta-analysis of five cross-sectional studies. Likewise, meta-analysis of RCTs and cohort studies indicated that consumption of VD were not associated with MetS components. Meta-analysis of cross-sectional studies demonstrated that VD were significantly associated with lower levels of SBP (mean difference [MD] -4.18 mmHg, 95%CI -5.57 to -2.80, p < 0.00001), DBP (MD -3.03 mmHg, 95% CI -4.93 to -1.13, p = 0.002), fasting glucose (MD -0.26 mmol/L, 95% CI -0.35to -0.17, p < 0.00001), WC (MD -1.63 cm, 95% CI -3.13 to -0.13, p = 0.03), and HDL-C (MD -0.05 mmol/L, 95% CI -0.07 to -0.03, p < 0.0001) in comparison to omnivorous diet. Heterogeneity of effects among cross-sectional studies was high. About, one-half of the included studies had high risk of bias.

CONCLUSIONS

VD in comparison with omnivorous diet is not associated with a lower risk of MetS based on results of meta-analysis of cross-sectional studies. The association between VD and lower levels of SBP, DBP, HDL-C, and fasting glucose is uncertain due to high heterogeneity across the cross-sectional studies. Larger and controlled studies are needed to evaluate the association between VD and MetS and its components.

Plant-Based Diet, Cholesterol, and Risk of Gallstone Disease: A Prospective Study

Vegetarian diets may lower symptomatic gallstone disease via cholesterol lowering. This study aimed to examine the risk of symptomatic gallstone disease (GSD) in Taiwanese vegetarians vs. nonvegetarians in a prospective cohort and to explore if this association is related to cholesterol concentration. We prospectively followed 4839 participants, and in the 29,295 person-years of follow-up, 104 new incident GSD cases were confirmed. Diet was assessed through a validated food frequency questionnaire. Symptomatic GSD was ascertained through linkage to the Taiwan National Health Insurance Research Database. Blood cholesterol profiles were measured at recruitment. Cox regression was applied to assess the effect of diet on symptomatic GSD, adjusting for age, education, smoking, alcohol, physical activities, diabetes, kidney diseases, body mass index, lipid-lowering medication, and hypercholesterolemia. Vegetarian diet was associated with a decreased risk of symptomatic GSD compared with nonvegetarian diet in women (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.28⁻0.96) but not in men. In women, nonvegetarians with hypercholesterolemia had 3.8 times the risk of GSD compared with vegetarians with normal cholesterol (HR, 3.81, 95% CI, 1.61⁻9.01). A vegetarian diet may therefore protect against GSD independent of baseline hypercholesterolemia. A nonvegetarian diet and hypercholesterolemia may have an additive effect in increasing GSD risk in women.

Cardiometabolic risk factors in vegans; A meta-analysis of observational studies

Background

There is increasing evidence that plant based diets are associated with lower cardiovascular risk.

Objective

To evaluate effects of a vegan compared to an omnivorous diet on cardio-metabolic risk factors.

Methods

Meta-analysis of observational studies published between 1960 and June 2018 that reported one or more cardio-metabolic risk factors in vegans and controls eating an omnivorous diet were undertaken. Macro-nutrient intake and cardio-metabolic risk factors were compared by dietary pattern. The Newcastle Ottawa Scale (NOS) was used to assess the quality of each study. The inverse-variance method was used to pool mean differences. Statistical analyses were performed using RevMan software version 5•2 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen.

Results

40 studies with 12 619 vegans and 179 630 omnivores were included. From food frequency questionnaires in 28 studies, vegans compared to omnivores consumed less energy (-11%, 95% confidence interval -14 to -8) and less saturated fat (- 51%, CI -57 to -45). Compared to controls vegans had a lower body mass index (-1.72 kg/m², CI -2.30 to -1.16), waist circumference (-2.35 cm, CI -3.93 to -0.76), low density lipoprotein cholesterol (-0.49 mmol/L CI -0.62 to -0.36), triglycerides (-0.14 mmol/L, CI -0.24 to -0.05), fasting blood glucose (-0.23 mmol/, CI -0.35 to -0.10), and systolic (-2.56 mmHg, CI -4.66 to -0.45) and diastolic blood pressure (-1.33 mmHg, CI -2.67 to -0.02), p<0.0001 for all. Results were consistent for studies with < and ≥ 50 vegans, and published before and after 2010. However in several large studies from Taiwan a vegan diet was not associated with favourable cardio-metabolic risk factors compared to the control diets.

Conclusion

In most countries a vegan diet is associated with a more favourable cardio- metabolic profile compared to an omnivorous diet.

Anthropometric and physiologic characteristics in white and British Indian vegetarians and nonvegetarians in the UK Biobank

Background

A detailed description of anthropometric and physiologic characteristics of persons in different diet groups is lacking.

Objective

We aimed to perform cross-sectional analyses of diet group with anthropometric and physiologic characteristics in a large cohort in the United Kingdom.

Design

The UK Biobank recruited ∼500,000 middle-aged participants throughout the United Kingdom in 2006-2010. Anthropometric indexes (height, weight, waist and hip circumference, body composition) and other physiologic characteristics (heel bone mineral density, grip strength, blood pressure, pulse rate) were measured following standardized protocols. We estimated the age-adjusted means of each characteristic in 6 diet groups (198,166 regular meat eaters, 199,784 low meat eaters, 4381 poultry eaters, 9674 fish eaters, 6366 vegetarians, and 378 vegans) in white women and men, and in 2 diet groups (3322 meat eaters and 1186 vegetarians) in British Indian women and men.

Results

In white women, after adjustment for age and compared with regular meat eaters, non-red meat eaters had lower adiposity (e.g., 4.5% lower body fat in vegan women) and lower systolic and diastolic blood pressure (-4.2 and -3.3 mm Hg, respectively), and generally lower heel bone mineral density t-score (-0.26). Patterns of differences by diet group were similar in white men. In the Indian population, compared with meat eaters, vegetarian women were shorter (-1.1 cm) and had lower lean mass (-0.5 kg), and both vegetarian women and men had lower grip strength (-1.3 and -1.4 kg, respectively). No significant differences in the other characteristics were observed.

Conclusions

Differences in anthropometric and physiologic characteristics were observed across diet groups in white participants, but fewer differences were observed in British Indian participants. The observed differences may be important as intermediate markers of long-term health in different diet groups. This observational study was registered at http://www.isrctn.com/ as ISRCTN10125697.

Vegetarian Dietary Patterns and Cardiovascular Disease

Cardiovascular (CV) disease (CVD) is the leading global cause of mortality, being responsible for 46% of non-communicable disease deaths. It has been estimated that about 85.6 million Americans are living with some form of CVD, which continues to rise. Healthy lifestyle choices may reduce the risk of myocardial infarction by >80%, with nutrition playing a key role. Vegetarian dietary patterns reduce CVD mortality and the risk of coronary heart disease (CHD) by 40%. Plant-based diets are the only dietary pattern to have shown reversal of CHD. Additionally, evidence suggests benefits of vegetarian dietary patterns in both the prevention and the treatment of heart failure and cerebrovascular disease. Plant-based diets are associated with lower blood pressure, lower blood lipids, and reduced platelet aggregation than non-vegetarian diets and are beneficial in weight management, reduce the risk of developing metabolic syndrome, and type 2 diabetes. They have also been shown an effective treatment method in diabetes management. Well planned vegetarian diets provide benefits in preventing and reversing atherosclerosis and in decreasing CVD risk factors and should be promoted through dietary guidelines and recommendations.

Potential impact of the digestible indispensable amino acid score as a measure of protein quality on dietary regulations and health

Regulatory frameworks for protein content claims in Canada and the United States are underpinned by the protein efficiency ratio and protein digestibility-corrected amino acid score (PDCAAS), respectively, which are used to assess the protein quality of a given food. The digestible indispensable amino acid score (DIAAS) is a novel approach to measuring the protein quality of foods and is supported by the Food and Agriculture Organization of the United Nations. Methodological concerns about the PDCAAS are addressed by the DIAAS through introduction of the use of ileal amino acid digestibility coefficients and untruncated protein scores. However, before the DIAAS is widely adopted within regulatory frameworks, a comprehensive assessment is required. Accordingly, this review addresses the potential impact of the DIAAS on regulation, communication, and public health, as well as knowledge gaps, analytical challenges, and cost of implementation. A pragmatic approach to addressing protein quality is advocated by suggesting the use of conservative coefficients of digestibility that are derived from in vitro methods. Before adopting the DIAAS as a framework for supporting protein content claims, updated food-related regulations and policies should also be evaluated through a lens that anticipates the impact on consumer-facing nutrition communication, the adoption of dietary patterns that are nutritionally adequate, and a food value chain that fosters a spirit of food and nutritional innovation.

A 48-Hour Vegan Diet Challenge in Healthy Women and Men Induces a BRANCH-Chain Amino Acid Related, Health Associated, Metabolic Signature

SCOPE

Research is limited on diet challenges to improve health. A short-term, vegan protein diet regimen nutritionally balanced in macronutrient composition compared to an omnivorous diet is hypothesized to improve metabolic measurements of blood sugar regulation, blood lipids, and amino acid metabolism.

METHODS AND RESULTS

This randomized, cross-over, controlled vegan versus animal diet challenge is conducted on 21 (11 female,10 male) healthy participants. Fasting plasma is measured during a 3 d diet intervention for clinical biochemistry and metabonomics. Intervention diet plans meet individual caloric needs. Meals are provided and supervised. Diet compliance is monitored.

CONCLUSIONS

The vegan diet lowers triglycerides, insulin and homeostatic model assessment (HOMA-IR), bile acids, elevated magnesium levels, and changed branched-chain amino acids (BCAAs) metabolism (p < 0.05), potentiating insulin and blood sugar control after 48 h. Cholesterol control improves significantly in the vegan versus omnivorous diets. Plasma amino acid and magnesium concentrations positively correlate with dietary amino acids. Polyunsaturated fatty acids and dietary fiber inversely correlate with insulin, HOMA-IR, and triglycerides. Nutritional biochemistries, BCAAs, insulin, and HOMA-IR are impacted by sexual dimorphism. A health-promoting, BCAA-associated metabolic signature is produced from a short-term, healthy, controlled, vegan diet challenge when compared with a healthy, controlled, omnivorous diet.

Dietary patterns, gender, and weight status among middle-aged and older adults in Taiwan: a cross-sectional study

Background

Diet has been associated with differences in weight and nutritional status of an individual. The prevalence of overweight and obesity increased among adults in Taiwan. Hence, we examined the relationship between dietary patterns and weight status by gender among middle-aged and older adults in Taiwan.

Methods

The cross-sectional data of 62,965 participants aged ≥40 years were retrieved from the Mei Jau health screening institutions’ database collected from 2001 and 2010. Diet information was evaluated using a food frequency questionnaire, while the dietary patterns were derived using principal component analysis before summing up and dividing into quintiles of consumption. The association between dietary patterns and weight status among adult men and women was explored using multinomial logistic regression models. Three models were analyzed before stratifying data by gender.

Results

Two dietary patterns were derived with one reflecting a high consumption of vegetables and fruits (vegetable-fruit dietary pattern) and the other a high consumption of meat and processed foods (meat-processed dietary pattern). After adjustment, highest consumption of vegetables and fruits (Q5) reduced the likelihood of being overweight (OR = 0.91; 95% CI, 0.85–0.97) or obese (OR = 0.85; 95% CI, 0.78–0.92), while highest consumption of meat and processed foods increased the likelihood of being overweight (OR = 1.50; 95% CI, 1.40–1.59) or obese (OR = 1.94; 95% CI, 1.79–2.10). Women were less likely to be overweight or obese with the highest intake of fruits and vegetables (Q5) while both genders were more likely to be overweight or obese with high consumption of meat and processed foods.

Conclusions

High intake of vegetables and fruits is associated with lower odds of being overweight or obese, especially among women. But, high intake of meat and processed foods is associated with higher odds of overweight and obesity in both genders.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0664-4) contains supplementary material, which is available to authorized users.

Vegetarian diet reduces the risk of hypertension independent of abdominal obesity and inflammation: a prospective study

OBJECTIVES

A vegetarian diet may prevent elevation of blood pressures and lower the risk for hypertension through lower degrees of obesity, inflammation, and insulin resistance. This study investigated the association between a vegetarian diet and hypertension incidence in a cohort of Taiwanese adult nonsmokers and examined whether this association was mediated through inflammation, abdominal obesity, or insulin resistance (using fasting glucose as a proxy).

METHODS

This matched cohort study was from the 1994-2008 MJ Health Screening Database. Each vegetarian was matched with five nonvegetarians by age, sex, and study site. The analysis included 4109 nonsmokers (3423 nonvegetarians and 686 vegetarians), followed for a median of 1.61 years. The outcome includes hypertension incidence, as well as SBP and DBP levels. Regression analysis was performed to assess the association between vegetarian diet and hypertension incidence or future blood pressure levels in the presence/absence of potential mediators.

RESULTS

Vegetarians had a 34% lower risk for hypertension, adjusting for age and sex (odds ratio: 0.66, 95% confidence interval: 0.50-0.87; SBP: -3.3 mmHg, P < 0.001; DBP: -1.5 mmHg, P < 0.001). The results stay statistically significant after further adjustment for C-reactive protein, waist circumference, and fasting glucose (odds ratio: 0.72, 95% confidence interval: 0.55-0.86; SBP: -2.4 mmHg, P < 0.05; DBP: -1.1 mmHg, P < 0.05). The protective association between vegetarian diet and hypertension appeared to be consistent across age groups.

CONCLUSION

Taiwanese vegetarians had lower incidence of hypertension than nonvegetarians. Vegetarian diets may protect against hypertension beyond lower abdominal obesity, inflammation, and insulin resistance.

Characteristics of Americans Choosing Vegetarian and Vegan Diets for Health Reasons

OBJECTIVE

Examine the prevalence, patterns, and associated factors of using a vegetarian or vegan diet for health reasons in the US general population.

DESIGN

Cross-sectional data from the 2012 National Health Interview Survey.

PARTICIPANTS

Nationally representative sample (N = 34,525).

VARIABLES MEASURED

Prevalence of ever use and 12-month use of vegetarian or vegan diet for health reasons, patterns of use, and sociodemographic and health-related factor associated with use.

ANALYSIS

Multiple logistic regression analysis.

RESULTS

Prevalence of ever use and 12-month use was 4.0% (n = 1,367) and 1.9% (n = 648), respectively. Health vegetarians and vegans were more likely aged 30-65 years, female, not Hispanic, from the Western US region, at least high school educated, chronically ill, and physically active. They were less likely to be in a relationship, overweight or obese, or smoking, or to have public or private health insurance. Among health vegetarians and vegans, 6.3% consulted with a practitioner for special diets; 26.1% followed the diet because of a specific health problem, mainly high cholesterol, overweight, hypertension, and diabetes; and 59.4% disclosed the diet to their health care provider.

CONCLUSIONS AND IMPLICATIONS

Less than 2% of participants reported using a vegetarian or vegan diet for health reasons within the past 12 months. Despite potential benefits of plant-based nutrition, more research is warranted on the actual use and its effects and safety.