Vegan Diet and Bone Health-Results from the Cross-Sectional RBVD Study

Bone mineral density parameters and related nutritional factors in vegans, lacto-ovo-vegetarians, and omnivores: a cross-sectional study

Introduction

The growing prevalence of vegetarianism determines the need for comprehensive study of the impact of these diets on health and particularly on bone metabolism. We hypothesized that significant dietary differences between vegans, lacto-ovo-vegetarians, and omnivores also cause significant differences in their nutrient status, which may affect bone health.

Methods

The study assessed dual-energy X-ray absorptiometry parameters in lumbar spine and femoral neck, average nutrient intake, serum nutrient concentrations, serum PTH levels, and urinary pH among 46 vegans, 38 lacto-ovo-vegetarians, and 44 omnivores.

Results

There were no differences in bone mineral density (BMD) between the groups. However, the parathyroid hormone (PTH) levels were still higher in vegans compared to omnivores, despite the same prevalence of hyperparathyroidism in all groups. These findings may probably be explained by the fact that each group had its own "strengths and weaknesses." Thus, vegans and, to a lesser extent, lacto-ovo-vegetarians consumed much more potassium, magnesium, copper, manganese, and vitamins B6, B9, and C. At the same time, the diet of omnivores contained more protein and vitamins D and B12. All the subjects consumed less vitamin D than recommended. More than half of vegans and omnivores had insufficiency or even deficiency of vitamin D in the blood. Low serum concentrations of manganese with its quite adequate intake are also noteworthy: its deficiency was observed in 57% of vegans, 79% of lacto-ovo-vegetarians, and 63% of omnivores.

Discussion

Currently, it is no longer possible to conclude that lacto-ovo-vegetarians have lower BMD than omnivores, as our research supported. Vegans in our study also did not demonstrate lower BMD values, only higher PTH blood concentrations, compared to omnivores, however, a large number of studies, including recent, show the opposite view. In this regard, further large-scale research is required. Vegans and lacto-ovo-vegetarians now have a variety of foods fortified with vitamins D and B12, as well as calcium. There is also a great diversity of ethically sourced dietary supplements. The found low concentrations of manganese require further investigation.

Risk of Bone Fracture on Vegetarian and Vegan Diets

PURPOSE OF REVIEW

Bone fractures can have a devastating effect on health, especially in the elderly, undermining their independence for daily activities, and increasing the risk of comorbidities and mortality. Nutrition is a key factor in maintaining an optimal bone health across the lifespan. The number of people that choose to avoid meat or even all animal products is increasing globally, for a diversity of reasons. Properly planned vegetarian and vegan diets are widely recognized as a healthy dietary pattern, but the long-term impact of these diets on bone health and more specifically risk of bone fractures is less clear. Classic studies have observed a slightly lower bone mineral density in vegetarians but have many limitations, including inadequate adjusting for relevant confounding factors, and cross-sectional design. The aim of this review is to summarize and put into context the current evidence on the effect of vegetarian and vegan diets on bone health, with a focus on fracture risk.

RECENT FINDINGS

In recent years, results from many large prospective studies have emerged, which allowed us to assess the risk of incident bone fractures in vegetarians. In these studies, vegetarian and especially vegan diets were associated with an increased risk of bone fractures. In many recent prospective cohort studies, vegetarian and especially vegan diets were associated with an increased risk of bone fractures. At least part of this risk could be due to a lower body mass index and a lower intake of nutrients such as calcium, vitamin D, and protein. Some evidence suggests that combined vitamin D and calcium supplementation and other factors such as consumption of protein-rich foods may attenuate this risk. The eventual deleterious effect of vegetarian diets on bone health should be contextualized and balanced with its benefits, such as lower risk of cardiovascular disease and cancer.

Nutritional therapy bridges the critical cut-off point for the closed-loop role of type 2 diabetes and bone homeostasis: A narrative review

Currently, osteoporosis-related fractures become the most cutting-edge problem of diabetes-related complications. Rational diet is not only the basis of glycemic management in type 2 diabetes patients, but also the direction of diabetic bone health. This review highlights the importance of micronutrient supplementation (including calcium, magnesium, zinc, vitamin D, vitamin K, and vitamin C) for patients with T2DM, as well as describing the constructive intermediary role of gut flora between T2DM and bone through nutrients predominantly high in dietary fiber. In addition, it is recommended to combine the Mediterranean dietary pattern with other diversified management approaches to prevent OP. Therefore, this provides a theoretical basis for the potential role of islet β-cells in promoting bone health.

Bone Remodelling, Vitamin D Status, and Lifestyle Factors in Spanish Vegans, Lacto-Ovo Vegetarians, and Omnivores

Sustainable healthy diets are promoted, and consequently vegetarian diets are currently increasing. However, scientific information on their effects on bone health is scarce. A cross-sectional study was performed in adults (66% women) classified into three groups: omnivores (n = 93), lacto-ovo vegetarians (n = 96), and vegans (n = 112). Nutrient intake, body composition, physical activity, vitamin D status (25-hydroxycholecalciferol, 25-OHD), parathormone (PTH), and bone formation (bone alkaline phosphatase, BAP) and resorption (N-telopeptides of type I collagen, NTx) markers were determined. Lacto-ovo vegetarians and especially vegans showed lower protein, fat, calcium, phosphorous, vitamin D, retinol, iodine, and zinc intakes, and higher carbohydrate, fibre, carotenes, magnesium, and vitamin K intakes compared to omnivores. Body composition was similar in the three groups that performed vigorous physical activity regularly. Body bone mass and muscle mass were positively correlated with BAP, and time performing physical activity with 25-OHD. The prevalence of vitamin D deficiency or insufficiency (25-OHD < 75 nmol/L) was 93.7% in the studied population, and vitamin D deficiency (25-OHD < 25 nmol/L) was significantly higher in vegans. Vegetarians of both groups had increased PTH and NTx with vegans showing significantly higher PTH and NTx than omnivores. Conclusion: Adult vegetarians, especially vegans, should reduce the risk of bone loss by appropriate diet planning and vitamin D supplementation.

Relationship between dietary characteristics and heel quantitative ultrasound parameters in postmenopausal women from the OsteoLaus cohort

The role of dietary patterns in the development of osteoporosis is unclear. The heel quantitative ultrasound (QUS) is a potential alternative to Dual X-Ray Absorptiometry. Nutrients, foods, dietary patterns and compliance to dietary guidelines were compared between the lowest and the highest tertiles of QUS parameters [Broadband Ultrasound Attenuation (BUA), Speed of Sound (SOS), Stiffness Index (SI)], using data from the OsteoLaus cohort. Participants in the highest tertiles of QUS parameters (385 for BUA, 397 for SOS, 386 for SI) were younger, of higher body weight, and had less major osteoporotic fractures. Women in the highest tertiles of SI and BUA consumed more fat (35.1 ± 0.4 vs 33.9 ± 0.4 and 34.9 ± 0.4 vs 33.8 ± 0.4 gr/day for SI and BUA, respectively, p < 0.05), and complied less frequently with dairy intake guidelines [odds ratio (95% confidence interval): 0.70 (0.53-0.92) and 0.72 (0.55-0.95) for SI and BUA, respectively, p < 0.05] than women in the lowest tertile. No differences were found regarding dietary patterns, healthy dietary scores, or compliance to dietary guidelines. Postmenopausal women in the highest QUS tertiles were younger, of higher weight and BMI, consumed more monounsaturated fatty acids and less dairy and calcium than women in the lowest tertiles. No differences were found between QUS tertiles regarding dietary patterns.

Meat consumption & positive mental health: A scoping review

The objective of this scoping review was to examine the breadth of the existing literature on the relation between meat consumption or meat abstention and positive psychological functioning. In April 2022, we conducted a systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, Cochrane Library, and Web of Science) for primary research examining positive psychological functioning in meat consumers and those who abstain from meat. Thirteen studies met the inclusion/exclusion criteria, representing 89,138 participants (54,413 females and 33,863 males) with 78,562 meat consumers and 10,148 meat abstainers (13-102 years) from multiple geographic regions. The primary outcomes were life satisfaction, "positive mental health", self-esteem, and vigor. The secondary outcomes were "meaning in life", optimism, positive emotions, and psychological well-being. Eight of the 13 studies demonstrated no differences between the groups on positive psychological functioning, three studies showed mixed results, and two studies showed that compared to meat abstainers, meat consumers had greater self-esteem, "positive mental health", and "meaning in life". Studies varied substantially in methods and outcomes. Although a small minority of studies showed that meat consumers had more positive psychological functioning, no studies suggested that meat abstainers did. There was mixed evidence for temporal relations, but study designs precluded causal inferences. Our review demonstrates the need for future research given the equivocal nature of the extant literature on the relation between meat consumption and meat abstention and positive psychological functioning.

Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian diets

Vegan and vegetarian diets are widely supported and adopted, but individuals following such diets remain at greater risk of iodine deficiency. This systematic review and meta-analysis was conducted to assess the iodine intake and status in adults following a vegan or vegetarian diet in the modern day. A systematic review and quality assessment were conducted from October 2020 to December 2022 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidance. Studies were identified in Ovid MEDLINE, Web of Science, PubMed, and Scopus. Eleven articles were eligible for review containing 4421 adults (aged ≥ 18 years). Vegan groups had the lowest median urinary iodine concentration (mUIC) (12·2/l). None of the dietary groups had mUIC within the optimal range for iodine status (100-200 µg/l) (WHO). Vegan diets had the poorest iodine intake (17·3 µg/d) and were strongly associated with lower iodine intake (P = < 0·001) compared with omnivorous diets. Lower intake in vegan diets was influenced by sex (P = 0·007), the presence of voluntary or absence of Universal Salt Iodisation (USI) programmes (P = 0·01 & P = < 0·001), and living in a country with adequate iodine nutrition (P = < 0·001). Vegetarians and particularly vegans living in countries with no current USI programme continue to have increased risk of low iodine status, iodine deficiency and inadequate iodine intake. Further research into the usefulness of mandatory fortification of vegan appropriate foods is required.

Spine, hip, and femoral neck bone mineral density in relation to vegetarian type and status among Taiwanese adults

We determined the association of vegetarian type and status with bone mineral density (BMD) Z-scores at the spine, hip, and femoral neck. Compared to non-vegetarians, current vegetarians, especially vegans, lacto-vegetarians, and lacto-ovo-vegetarians had lower Z-scores at multiple sites. Sole reliance on a vegetarian diet might be detrimental to the bone.

PURPOSE

The impact of vegetarian diets on BMD is contentious. We determined the association of vegetarian type and status with the spine, hip, and femoral neck BMD Z-scores.

METHODS

We analyzed data from 20,110 Taiwan Biobank volunteers. BMD was measured using dual-energy X-ray absorptiometry (DXA). The vegetarian status (non-, former, and current vegetarians) and type (non-vegetarians, ovo-vegetarians, lacto-vegetarians, lacto-ovo-vegetarians, and vegans) were determined using questionnaires.

RESULTS

The participants consisted of 12,910 women and 7200 men, with a mean age of 55.5 years. Based on vegetarian status (reference: non-vegetarians), current vegetarians had significantly lower BMD Z-scores at the spine (unstandardized regression coefficient, B =  - 0.195, p = 0.006), left hip (B =  - 0.125, p = 0.008), and right hip (B =  - 0.100, p = 0.027), respectively. Based on vegetarian status and type (reference: non-vegetarians), current vegans and non-vegans had notably lower BMD Z-scores at specific skeletal sites. For non-vegans, the BMD Z-scores were significant at the spine (B = -0.184, p = 0.010), left hip (B =  - 0.124, p = 0.010), and left femoral neck (B =  - 0.125, p = 0.012). For current vegans, however, the BMD Z-scores were significant only at the right hip (B =  - 0.232; p = 0.028). Nonetheless, after stratifying vegetarian diet into more subgroups, current vegans exhibited a significant reduction in BMD Z-scores at the spine and right hip, with B-coefficients of - 0.326 and - 0.238, respectively. Current lacto-vegetarians also had significantly lower Z-scores (p < 0.05) at the spine (B =  - 0.459), left hip (B =  - 0.313), and right hip (B =  - 0.214). Moreover, current lacto-ovo-vegetarians had significantly lower Z-scores at the spine (B =  - 0.175) and left hip (B =  - 0.115).

CONCLUSION

Current vegetarians, particularly vegans, lacto-vegetarians, and lacto-ovo-vegetarians, demonstrated significantly lower BMD Z-scores at various skeletal sites compared to non-vegetarians. Sole reliance on a vegetarian diet might be detrimental to the bone.

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.

Vegan Diets for Children: A Narrative Review of Position Papers Published by Relevant Associations

The scientific discourse on vegan diets for children and adolescents primarily involves referencing position statement papers from different scientific and professional organizations, including paediatric associations. Over the past two decades, specialized associations have issued official statements and published position papers about adopting well-designed vegan diets during crucial life stages, including pregnancy and lactation, infancy, and childhood. A subset of these associations firmly supports the notion that a well-designed vegan diet can indeed be healthy and support normal growth and development during particularly delicate life stages, emphasizing careful planning, vitamin B12 supplementation, and regular supervised medical and dietetics oversight. In contrast, specific paediatric associations caution against vegan diets for children and adolescents, citing potential harm and the lack of adequate substantiation. These criticisms in position papers frequently point to lower-quality studies and/or outdated studies. Additionally, concerns extend to comparing vegan and omnivorous diets, considering public health issues such as obesity and early stages of cardiovascular disease as well as the risk of prediabetes and type 2 diabetes. Notably, some scepticism stems from studies where children's adherence to a well-designed vegan diet is incomplete. Scientific rigor suggests performing a comparable assessment of omnivorous and vegan diets. This narrative review highlights the need for a comprehensive, up-to-date literature review to inform balanced perspectives on vegan diets for children and adolescents. Researchers and decision-makers should aim to actively improve the design and consistent implementation of both diet types.

Novel plant-based meat alternatives: Implications and opportunities for consumer nutrition and health

Against the backdrop of the global protein transition needed to remain within planetary boundaries, there is an influx of plant-based meat alternatives that seek to approximate the texture, flavor and/or nutrient profiles of conventional animal meat. These novel plant-based meat alternatives, enabled by advances in food technology, can be fundamentally different from the whole-plant foods from which they are derived. One of the reasons is the necessity to use food additives on various occasions, since consumers' acceptance of plant-based meat products primarily depends on the organoleptic properties. Consequently, a high degree of heterogeneity in formulation and nutritional profiles exists both within and between product categories of plant-based meat alternatives with unknown effects on several aspects of human health. This is further complicated by the differences in digestibility and bioavailability between proteins from animal and plant sources, which have a profound impact on colonic fermentation, nutritional adequacy and potential health effects. On the other hand, emerging strategies provide opportunities to develop affordable, delicious and nutritious plant-based meat alternatives that align with consumer interests.

Can the Substitution of Milk with Plant-Based Drinks Affect Health-Related Markers? A Systematic Review of Human Intervention Studies in Adults

The consumption of plant-based drinks (PBDs) in substitution for cow's milk (CM) is increasing due to concerns for human and planet health and animal welfare. The present review aims to analyze the main findings from intervention trials investigating the effect of PBDs in comparison with CM on markers of human health. Suitable articles published up to July 2022 were sourced from PubMed and Scopus databases. A total of 29 papers were collected, with 27 focusing on soy drinks (1 of which also evaluated the effects of an almond drink), while only 2 focused on rice drinks. Among studies focused on soy drinks, the most investigated factors were anthropometric parameters (n = 13), the lipid profile (n = 8), markers of inflammation and/or oxidative stress (n = 7), glucose and insulin responses (n = 6) and blood pressure (n = 4). Despite some evidence of a beneficial effect of PBDs, especially for the lipid profile, it was not possible to draw any overall conclusions due to some conflicting results. As well as the low number of studies, a wide heterogeneity was found in terms of the characteristics of subjects, duration and markers, which reduces the strength of the available results. In conclusion, further studies are needed to better elucidate the effects of substituting CM with PBDs, especially in the long term.

Dietary Intake and Circulating Amino Acid Concentrations in Relation with Bone Metabolism Markers in Children Following Vegetarian and Omnivorous Diets

Scientific studies reported that most vegetarians meet the total protein requirements; however, little is known about their amino acid intakes. We aimed to assess dietary intake and serum amino acid levels in relation to bone metabolism markers in prepubertal children on vegetarian and traditional diets. Data from 51 vegetarian and 25 omnivorous children aged 4–9 years were analyzed. Dietary intake of macro- and micronutrients were assessed using the nutritional program Dieta 5®. Serum amino acid analysis was performed using high-pressure liquid chromatography technique, 25-hydroxyvitamin D and parathormone–electrochemiluminescent immunoassay, and bone metabolism markers, albumin, and prealbumin levels using enzyme-linked immunosorbent assay. Vegetarian children had a significantly lower intake of protein and amino acids with median differences of about 30–50% compared to omnivores. Concentrations of four amino acids (valine, lysine, leucine, isoleucine) in serum varied significantly by diet groups and were lower by 10–15% in vegetarians than meat-eaters. Vegetarian children also had lower (p < 0.001) serum albumin levels compared to omnivores. Among bone markers, they had higher (p < 0.05) levels of C-terminal telopeptide of collagen type I (CTX-I) than omnivores. Correlation patterns between amino acids and bone metabolism markers differed in the vegetarian and omnivore groups. Out of bone markers, especially osteoprotegerin was positively correlated with several amino acids, such as tryptophan, alanine, aspartate, glutamine, and serine, and ornithine in vegetarians. Vegetarian children consumed apparently sufficient but lower protein and amino acids compared to omnivores. In circulation these differences were less marked than in the diet. Significantly lower amino acid intake and serum levels of valine, lysine, leucine, and isoleucine as well as the observed correlations between serum amino acids and biochemical bone marker levels indicated the relations between diet, protein quality, and bone metabolism.

Change to a Plant-Based Diet Has No Effect on Strength Performance in Trained Persons in the First 8 Weeks-A 16-Week Controlled Pilot Study

Over the past few years, the number of people who have avoided animal products has been rising steadily. A plant-based diet is associated with a healthier lifestyle and has positive effects on various diseases. More and more healthy active people and performance-orientated athletes are giving up animal products for various reasons, such as for an improved performance or faster regeneration. However, the data in this context are limited. This study aimed to obtain initial findings on the influence of a diet change to veganism on the performance of strength-trained individuals. For this study, a total of 15 omnivorous individuals were recruited. They documented their dietary food intakes over 16 weeks. Every four weeks, the strength performance was tested via a leg press and bench press. In the first 8 weeks, the participants maintained their omnivorous diet, followed by 8 weeks of a vegan dietary phase. In total, 10 subjects participated successfully, and their data were part of the statistical analyses. There was no difference in the absolute and relative strength performance for the leg and bench press after changing to a vegan diet. For the total calorie intake and carbohydrates, only a small treatment effect, but no time effect, was observed. However, for the protein intake, a time and group effect were detected. In addition, the relative protein intake decreased significantly and was lower than the current recommendations for athletes. The results demonstrate that a change to a vegan diet has no beneficial nor negative effect on the strength performance when the total calorie intake and carbohydrate content are covered in the first 8 weeks.

Stable isotope ratios of nitrogen and carbon as biomarkers of a vegan diet

PURPOSE

Dietary biomarkers can potentially overcome the limitations of self-reported dietary data. While in ecology and archaeology, stable isotope ratios of carbon and nitrogen are widely used as biomarkers, this is not the case in nutrition research. Since the abundance of the 13C and the 15N isotope differ in food sources from plant and animal origin, stable isotope ratios of carbon and nitrogen (δ13C and δ15N) may differ in human biological material. Here, we investigated the stable isotope ratios of nitrogen and carbon in serum and urine from vegans and omnivores.

METHOD

Measurement of δ15N and δ13C in serum and 24 h urine was performed by Elemental Analyzer-Isotope Ratio Mass Spectrometer in the cross-sectional study "Risks and Benefits of a Vegan Diet". The study included 36 vegans and 36 omnivores with a median age of 37.5 years (matched for age and sex), who adhered to their diet for at least 1 year.

RESULTS

Both δ15N and δ13C were significantly lower in both the serum and 24 h urine of vegans compared to omnivores. δ15N either in serum or urine had 100% specificity and sensitivity to discriminate between vegans and omnivores. Specificity of δ13C was also > 90%, while sensitivity was 93% in serum and 77% in urine.

CONCLUSION

δ15N both in serum and urine was able to accurately identify vegans and thus appears to be a promising marker for dietary habits.

Fracture Risk in Vegetarians and Vegans: the Role of Diet and Metabolic Factors

PURPOSE OF REVIEW

There is strong evidence that poor dietary intake of certain micro- and macro-nutrients can negatively affect bone health. It is unclear if diet is the primary culprit for poor bone health in the vegan population.

RECENT FINDINGS

Plant-based diets are gaining public interest since they may improve metabolic health. Studies that examine vegetarians and vegans together show a lower bone mineral density (BMD), but not always increased fracture risk compared to omnivores. However, vegans consistently have higher risk of fracture at multiple bone sites, especially at the hip. There is higher fracture risk in vegans which may be due to calcium and vitamin D intake, as well as amount of dietary protein and quality. Other nutrients (B vitamins, Se, Zn, Fe, iodine) or physiological factors (lower body mass index, microbiome, or endocrine profile) may also play a role but have not been examined and require further study.

Urinary Potential Renal Acid Load (uPRAL) among Vegans Versus Omnivores and Its Association with Bone Health in the Cross-Sectional Risks and Benefits of a Vegan Diet Study

Both veganism and high dietary acid load are linked to unfavorable bone health. However, the specific role of dietary alkali or acid load for the bone health of vegans is so far unknown. Thus, the renal biomarker for dietary acid or alkali load, i.e., urinary potential renal acid load (uPRAL), was measured in 24 h urine samples of 34 vegans and 35 omnivores (50.7% males). Bone health was assessed via calcaneal quantitative ultrasound. Associations between uPRAL and bone health indices were examined using multivariable general linear models. Compared to omnivores, vegans had a significantly lower uPRAL (mean difference = −34.5 mEq/24 h, p < 0.0001), a lower 24 h urinary phosphate excretion (p = 0.0004), a lower 24 h urinary sulfate excretion (p = 0.01), and a higher urine pH value (p < 0.0001). Broadband ultrasound attenuation (BUA) was lower among vegans versus omnivores (p = 0.037), yet it was not associated with uPRAL irrespective of adjustments. This study confirms different acid-base profiles of vegans and omnivores, with a pronounced alkaline excess among vegans and a rather low acid load among a group of omnivores with moderate protein intake. Within this spectrum of alkaline to low acid load, no association with bone health was found.

Greater Protection of Lower Dietary Carbohydrate to Fiber Ratio (CFR) against Poor Blood Pressure Control in Patients with Essential Hypertension: A Cross-Sectional Study

(1) Background: Carbohydrate combined with dietary fiber (DF) applied as a surrogate marker of overall carbohydrate quality is a more essential determinant of cardiometabolic health. However, to date, no studies have applied this metric to analyze its associations with poor blood pressure control in hypertensive patients. (2) Methods: A cross-sectional design was implemented in one tertiary hospital and one community hospital in China. Using Feihua Nutrition Software to analyze participants' two-day dietary log, the quantity of carbohydrate and fiber was obtained and the carbohydrate to fiber ratio (CFR) was calculated. The participants were divided into Q1, Q2, Q3, and Q4 groups by quartile method, from low to high according to CFR. The poor systolic and diastolic blood pressure (SBP and DBP) controls were defined as ≥140 mmHg and ≥90 mmHg, respectively. (3) Results: A convenience sample of 459 participants was included and the mean CFR was 29.6. Taking Q1 as reference, after adjusting for covariates, the CFR in Q4 was associated with higher poor SBP-controlled rate (OR, 4.374; 95% CI, 2.236-8.559). Taking Q2 as reference, after adjusting for covariates, the CFRs in Q3 and Q4 were associated with higher poor DBP-controlled rates [(OR = 1.964, 95% CI: 1.016-3.795) and (OR = 4.219, 95% CI: 2.132-8.637), respectively]. The CFR was the stronger protective determinant of SBP and DBP than DF or carbohydrate alone. (4) Conclusions: A higher CFR is a stronger risk factor for blood pressure (BP) control, and low CFR foods or a combination of corresponding food components, should be recommended in the dietary management of hypertensive patients.

Self-reported Resistance Training Is Associated With Better HR-pQCT-derived Bone Microarchitecture in Vegan People

CONTEXT

A plant-based lifestyle is a global trend; lower bone mineral density and increased fracture risk in vegan people are reported.

OBJECTIVE

The primary objective was to assess trabecular and cortical bone microarchitecture in vegans and omnivores. Secondary objectives were to evaluate relationships between bone microarchitecture, nutrition parameters, and physical activity.

METHODS

This was an observational study at the Medical Department II, St. Vincent Hospital (tertiary referral center for gastrointestinal, metabolic, and bone diseases, and teaching hospital of the Medical University of Vienna), including 43 healthy nonobese female and male subjects on a plant-based diet for at least 5 years, and 45 healthy nonobese female and male subjects on an omnivore diet for at least 5 years. The main outcome measures were the parameters of trabecular and cortical bone microarchitecture (high-resolution peripheral quantitative computed tomography), serum markers of bone turnover, nutrient intake (nutrition protocol), and self-reported resistance training (physical activity questionnaires).

RESULTS

In the vegan group, trabecular and cortical structure were altered compared with omnivores. Vegans not reporting resistance training had diminished bone microarchitecture compared with omnivores not reporting resistance training. In vegans and omnivores reporting resistance training, bone structure was similar. In both vegan subgroups (resistance training and not resistance training), a small number of correlations between nutrient intake and bone microarchitecture were observed without a conclusive pattern.

CONCLUSION

Bone microarchitecture in vegans differed from matched omnivores but could not be explained solely by nutrient uptake. These differences were attenuated between the subgroups reporting resistance training. In addition to a well-planned diet, progressive resistance training on a regular basis should be part of the vegan lifestyle.

The Effect of Yogurt and Kefir Starter Cultures on Bioactivity of Fermented Industrial By-Product from Cannabis sativa Production—Hemp Press Cake

Cannabis sativa (hemp) is a plant considered to be abundant in bioactive compounds. The increasing production of hemp oil is leaving considerable amounts of hemp press cakes (HPC), which have not been sufficiently managed so far. One of the directions of development of plant-based food is the use of by-products of the agri-food industry in accordance with the idea of zero waste and the circular economy, so the purpose of this study was to determine the possibility of HPC fermentation using yogurt and kefir cultures and to determine the effect of the type of starter on the properties of the products. In the present study, starter cultures of yogurt (YO 122) and kefir (commercial grains) were used for HPC fermentation. Changes in lactic acid bacteria (LAB) and yeast population, pH, acidity, the content of bioactive compounds by spectrophotometric methods (proteins, amino acids, polyphenols, flavonoids, reducing sugars) and antioxidant activity (DDPH, ABTS, FRAP and reducing power) were determined. The results showed that it was possible to develop high-value beverages based on HPC with high fermentation efficiency: survivability of LAB and yeast (>106 CFU/g) and acidification (pH in a range of 4.82–6.36 and 5.34–6.49 for yogurt and kefir culture, respectively). Moreover, the stability of hemp protein, with its variable free amino acid composition, antioxidant potential and presented changes in polyphenolic content, was observed during storage. The presented results show a new way to manage HPC as an oil industry residue by using it as a raw material for the development of a bioactive food product and illustrate the relationship between applied starter culture, the direction of fermentation and changes in the content of bioactive compounds.

Vegan nutrition: a preliminary guide for health professionals

Since the beginning of the 21st century, interest in vegan diets has been rapidly increasing in most countries. Misconceptions about vegan diets are widespread among the general population and health professionals. Vegan diets can be health-promoting and may offer certain important advantages compared to typical Western (and other mainstream) eating patterns. However, adequate dietary sources/supplements of nutrients of focus specific to vegan diets should be identified and communicated. Without supplements/fortified foods, severe vitamin B12 deficiency may occur. Other potential nutrients of focus are calcium, vitamin D, iodine, omega-3 fatty acids, iron, zinc, selenium, vitamin A, and protein. Ensuring adequate nutrient status is particularly important during pregnancy, lactation, infancy, and childhood. Health professionals are often expected to be able to provide advice on the topic of vegan nutrition, but a precise and practical vegan nutrition guide for health professionals is lacking. Consequently, it is important and urgent to provide such a set of dietary recommendations. It is the aim of this article to provide vegan nutrition guidelines, based on current evidence, which can easily be communicated to vegan patients/clients, with the goal of ensuring adequate nutrient status in vegans.

Vegans and vegetarians living in Nottingham (UK) continue to be at risk of iodine deficiency

Iodine is essential for thyroid hormone synthesis. Individuals adhering to vegan and vegetarian diets have been found to be vulnerable to iodine deficiency. Yet, iodine has not been monitored in these groups across time. This study aims to investigate iodine status, intake and knowledge in vegans, vegetarians and omnivores and determine changes between 2016-2017 and 2019. Dietary intake (µg/d) was estimated by 3-d food diaries and iodine FFQ. Urinary iodine concentration, analysed by inductively coupled plasma mass spectrometry, assessed iodine status according to WHO criteria. Iodine knowledge was scored by an adapted questionnaire. IBM SPSS was used for statistical analysis. Ninety-six adults (18-60 years) were recruited in October 2016-2017 (vegans: 12; vegetarians: 5; omnivores: 43) and June 2019 (vegans: 7; vegetarians: 10;omnivores: 19). Median dietary iodine was below the Reference Nutrient Intake for all groups. Vegans and vegetarians had the lowest iodine intake. Vegans had significantly lower iodine intake than omnivores (2016-2017, P = 0 032; 2019, P = 0 001). Omnivores had the highest iodine status (2016-2017, 79 4 µg/l; 2019, 72 4 µg/l) and vegans the lowest (2016-2017, 31 2 µg/l; 2019, 12 2 µg/l). Iodine knowledge was poor but did not differ between dietary groups (2016-2017, P = 0 219; 2019, P = 0 532). Vegans and vegetarians continue to be at risk of iodine deficiency. Further, iodine intake in the UK is poor independent of dietary choice. Iodine education is needed along with research into improving iodine nutrition at national level.

Amino acid intake and plasma concentrations and their interplay with gut microbiota in vegans and omnivores in Germany

Purpose

It has been estimated that most vegans meet the total protein requirements, but whether this is also true for individual essential amino acids (AAs) is unclear. Furthermore, a shift in protein intake is suggested to alter microbiota composition, but this association is unknown in terms of veganism or individual AAs. This cross-sectional study compared vegans and omnivores regarding dietary intake and plasma concentration of AAs. The prevalence of insufficient intake of essential AAs among vegans was determined using estimated average requirements (EAR) of WHO. Moreover, correlations between AAs intake and gut microbiota were investigated.

Methods

Data of 36 vegans and 36 omnivores (30–60 years) were analysed. AA intake, AA plasma concentrations and gut microbiota were ascertained by three-day weighed food protocols, gas/liquid chromatography-tandem mass spectrometry and 16S rRNA sequencing, respectively.

Results

At almost the same energy intake, the intake of 9 AAs in vegans was significantly lower than in omnivores, with median differences of − 27.0% to − 51.9%. However, only one female vegan showed total protein and lysine intake below the EAR. Vegans showed lower lysine (− 25.0%), but higher glycine (+ 25.4%) and glutamate (+ 13.1%) plasma concentrations than omnivores. Correlation patterns between AA intake and bacterial microbiota differed between vegans and omnivores. In vegans 19 species and in omnivores 5 species showed correlations with AA intake.

Conclusion

Vegans consumed apparently sufficient but lower AAs than omnivores. In addition, the different AAs intake seems to influence the microbiota composition. The use of short-term dietary data without considering usual intake limits these findings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02790-y.

The effects of vegetarian diets on bone health: A literature review

In these recent years many people are adopting a vegetarian type diet due to the numerous positive health effects of this regimen such as the reduction of the incidence of many chronic disorders like diabetes, hypertension, obesity and cancer. However this diet is quite restrictive and so it could be possible to have a deficiency in some specific nutrients, increasing the risk of osteoporosis and fractures. Although there are conflicting results on the effects of the vegetarian diet on bone health and fracture incidence, it is always recommendable in vegetarian people to have an adequate intake of calcium and vitamin D, through an increased intake of supplements, natural and fortified foods, an adequate intake of protein, fruit, vegetables, as well as vitamin B12. The aim of this literature review is to revise the actual knowledge of the effect of some nutrients and vegetarian diets on bone health.

Placing a Well-Designed Vegan Diet for Slovenes

Interest in vegan diets has increased globally as well as in Slovenia. The quantity of new scientific data requires a thorough synthesis of new findings and considerations about the current reserved position of the vegan diet in Slovenia. There is frequently confusion about the benefits of vegetarian diets that are often uncritically passed on to vegan diets and vice versa. This narrative review aims to serve as a framework for a well-designed vegan diet. We present advice on how to maximize the benefits and minimize the risks associated with the vegan diet and lifestyle. We highlight the proper terminology, present the health effects of a vegan diet and emphasize the nutrients of concern. In addition, we provide guidance for implementing a well-designed vegan diet in daily life. We conducted a PubMed search, up to November 2021, for studies on key nutrients (proteins, vitamin B12, vitamin D, omega-3 long chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), calcium, iron, zinc, iodine and selenium) in vegan diets. Given the limited amount of scientific evidence, we focus primarily on the general adult population. A well-designed vegan diet that includes a wide variety of plant foods and supplementation of vitamin B12, vitamin D in the winter months and potentially EPA/DHA is safe and nutritionally adequate. It has the potential to maintain and/or to improve health. For physically active adult populations, athletes or individuals with fast-paced lifestyles, there is room for further appropriate supplementation of a conventional vegan diet according to individuals' health status, needs and goals without compromising their health. A healthy vegan lifestyle, as included in government guidelines for a healthy lifestyle, includes regular physical activity, avoidance of smoking, restriction of alcohol and appropriate sleep hygiene.

Perspective: Striking a Balance between Planetary and Human Health: Is There a Path Forward?

The global adoption of predominantly plant-based sustainable healthy diets will help reduce the risk of obesity- and malnutrition-related non-communicable diseases while protecting the future health of our planet. This review examines the benefits and limitations of different types of plant-based diets in terms of health and nutrition, affordability and accessibility, cultural (ethical and religious) acceptability, and the environment (i.e., the four pillars underlying sustainable healthy diets). Results suggest that, without professional supervision, traditional plant-based diets (vegan, vegetarian and pescatarian diets) can increase the risk of nutritional deficiencies among infants, children/adolescents, adult females, pregnant/lactating women and the elderly. In contrast, flexitarian diets and territorial diversified diets (TDDs, e.g., Mediterranean and New Nordic diets) that include large quantities of plant-sourced foods, low levels of red meat and moderate amounts of poultry, fish, eggs and dairy can meet the energy and nutrition needs of different populations without the need for dietary education or supplementation. Compared to vegan, vegetarian and pescatarian diets, more diverse flexitarian diets and TDDs are associated with reduced volumes of food waste and may be more acceptable and easier to maintain for people who previously followed western diets. Although flexitarian diets and TDDs have a greater impact on the environment than vegan, vegetarian and pescatarian diets, the negative effects are considerably reduced compared to western diets, especially if diets include locally-sourced seasonal foods. Further studies are required to define more precisely optimal sustainable healthy diets for different populations and to ensure that diets are affordable and accessible to people in all countries.

The influence of vegetarian and vegan diets on the state of bone mineral density in humans

There are so many literatures about vegetarians being less prone to chronic, noninfectious diseases, which are, however, the main cause of the decline in quality of life and mortality in developed countries.However, according to various scientific sources, vegetarian and especially vegan diets often contain less saturated fats, protein, calcium, vitamins D and B12, or long-chain ω-3 PUFAs. One of the most common pathology associated with a predominantly plant diet is osteopenia and osteoporosis. An analysis of 13 studies has shown that vegetarians and vegans are at a higher risk of reducing of bone mineral density, thereby increasing the incidence of fractures.At the same time, plant-based diets are usually richer in many other micronutrients important for bone health: vitamins C and K, carotenoids, potassium, magnesium, manganese, copper, or silicon. Moreover, with the deepening of our knowledge about the role of nutrients in the body and the features of the nutritional status of the population, the quality of vegetarian and vegan diets also increases. They are less and less prone to micronutrient deficiencies. Recent studies show that BMD, as well as the risk of osteoporotic fractures, at least in vegetarians, equaled these indicators in omnivores.

The Nutritional Supply of Iodine and Selenium Affects Thyroid Hormone Axis Related Endpoints in Mice

Selenium and iodine are the two central trace elements for the homeostasis of thyroid hormones but additional trace elements such as iron, zinc, and copper are also involved. To compare the primary effects of inadequate intake of selenium and iodine on the thyroid gland, as well as the target organs of thyroid hormones such as liver and kidney, mice were subjected to an eight-week dietary intervention with low versus adequate selenium and iodine supply. Analysis of trace element levels in serum, liver, and kidney demonstrated a successful intervention. Markers of the selenium status were unaffected by the iodine supply. The thyroid gland was able to maintain serum thyroxine levels even under selenium-deficient conditions, despite reduced selenoprotein expression in liver and kidney, including deiodinase type 1. Thyroid hormone target genes responded to the altered selenium and iodine supply, whereas the iron, zinc, and copper homeostasis remained unaffected. There was a notable interaction between thyroid hormones and copper, which requires further clarification. Overall, the effects of an altered selenium and iodine supply were pronounced in thyroid hormone target tissues, but not in the thyroid gland.

Affordability of Different Isocaloric Healthy Diets in Germany-An Assessment of Food Prices for Seven Distinct Food Patterns

Affordability of different isocaloric healthy diets in Germany—an assessment of food prices for seven distinct food patterns Background: For decades, low-fat diets were recommended as the ideal food pattern to prevent obesity, type 2 diabetes and their long-term complications. Nowadays, several alternatives considering sources and quantity of protein, fat and carbohydrates have arisen and clinical evidence supports all of them for at least some metabolic outcomes. Given this variety in diets and the lack of a single ideal diet, one must evaluate if patients at risk, many of which having a lower income, can actually afford these diets. Aim: We modelled four-week food plans for a typical family of two adults and two school children based on seven different dietary patterns: highly processed standard omnivore diet (HPSD), freshly cooked standard omnivore diet (FCSD), both with German average dietary composition, low-protein vegan diet (VeganD), low-fat vegetarian diet (VegetD), low-fat omnivore diet (LFD), Mediterranean diet (MedD) and high-fat moderate-carb diet (MCD). The isocaloric diets were designed with typical menu variation for all meal times. We then assessed the lowest possible prices for all necessary grocery items in 12 different supermarket chains, avoiding organic foods, special offers, advertised exotic super foods and luxury articles. Prices for dietary patterns were compared in total, stratified by meal time and by food groups. Results: Among all seven dietary patterns, price dispersion by supermarket chains was 12–16%. Lowest average costs were calculated for the VegetD and the FCSD, followed by HPSD, LFD, VeganD, MedD and—on top—MCD. VeganD, MedD and MCD were about 16%, 23% and 67% more expensive compared to the FCSD. Major food groups determining prices for all diets are vegetables, salads and animal-derived products. Calculations for social welfare severely underestimate expenses for any kind of diet. Conclusions: Food prices are a relevant factor for healthy food choices. Food purchasing is financially challenging for persons with very low income in Germany. Fresh-cooked plant-based diets are less pricy than the unhealthy HPSD. Diets with reduced carbohydrate content are considerably more expensive, limiting their use for people with low income. Minimum wage and financial support for long-term unemployed people in Germany are insufficient to assure a healthy lifestyle.

Unintended Consequences: Nutritional Impact and Potential Pitfalls of Switching from Animal- to Plant-Based Foods

Consumers are shifting towards plant-based diets, driven by both environmental and health reasons. This has led to the development of new plant-based meat alternatives (PBMAs) that are marketed as being sustainable and good for health. However, it remains unclear whether these novel PBMAs to replace animal foods carry the same established nutritional benefits as traditional plant-based diets based on pulses, legumes and vegetables. We modelled a reference omnivore diet using NHANES 2017–2018 data and compared it to diets that substituted animal products in the reference diet with either traditional or novel plant-based foods to create flexitarian, vegetarian and vegan diets matched for calories and macronutrients. With the exception of the traditional vegan diet, all diets with traditional plant-based substitutes met daily requirements for calcium, potassium, magnesium, phosphorus, zinc, iron and Vitamin B12 and were lower in saturated fat, sodium and sugar than the reference diet. Diets based on novel plant-based substitutes were below daily requirements for calcium, potassium, magnesium, zinc and Vitamin B12 and exceeded the reference diet for saturated fat, sodium and sugar. Much of the recent focus has been on protein quality and quantity, but our case study highlights the risk of unintentionally increasing undesirable nutrients while reducing the overall nutrient density of the diet when less healthy plant-based substitutes are selected. Opportunities exist for PBMA producers to enhance the nutrient profile and diversify the format of future plant-based foods that are marketed as healthy, sustainable alternatives to animal-based products.

Internal exposure to perfluoroalkyl substances (PFAS) in vegans and omnivores

Perfluoroalkyl substances (PFAS) are a complex group of anthropogenic compounds with exceptional properties. Due to their high persistence and mobility, they have caused ubiquitous environmental contamination and in part accumulate in the food chain. In the general population, diet is the main source of PFAS exposure, with the important sources fish and meat. As a vegan diet implies the complete exclusion of any animal products, it might be expected that vegans have lower blood levels of PFAS compared to omnivores. Furthermore, lower levels of cholesterol is one of the well-documented nutritional effects in vegans, but cholesterol levels were also found to be associated with higher PFAS levels in epidemiological studies. To examine the relations of internal PFAS levels and the levels of cholesterol in vegans and omnivores, the cross-sectional "Risks and Benefits of a Vegan Diet" (RBVD) study was used involving 36 vegans and 36 omnivores from Berlin/Germany. Nine perfluoroalkyl substances were quantified in plasma using a triple-stage quadrupole mass spectrometer. Lower median plasma concentrations were found in vegans compared to omnivores for perfluorooctane sulfonic acid (PFOS) (2.31 vs. 3.57 ng/ml, respectively; p = 0.02) and for perfluorononanoic acid (PFNA) (<0.25 vs. 0.41 ng/ml, respectively; p < 0.0001). No significant differences of the median concentrations were observed for perfluorooctanoic acid (PFOA) (1.69 vs. 1.44 ng/ml, respectively, p = 0.26) and perfluorohexane sulfonic acid (PFHxS) (1.96 vs. 1.79 ng/ml, respectively; p = 0.70). The strongest correlations with food groups, derived from a food frequency questionnaire, were observed between levels of PFOA and water consumption (in case of the total study population, n = 72), and between levels of PFOS as well as PFNA and the consumption of 'meat and meat products' (in case of the omnivores, n = 36). Levels of Low Density Lipoprotein (LDL) cholesterol were confirmed to be considerably lower in vegans compared to omnivores (86.5 vs. 115.5 mg/dl, respectively; p = 0.001), but no associations between the four main PFAS and LDL cholesterol were observed (all p > 0.05) at the low exposure level of this study. According to the results of our study, a vegan diet may be related to lower PFAS levels in plasma. We highlight the importance of the adjustment of dietary factors like a vegan diet in case of epidemiological studies dealing with the impact of PFAS on the levels of blood lipids.

Vegetarian Diet: An Overview through the Perspective of Quality of Life Domains

Vegetarianism has gained more visibility in recent years. Despite the well-described effects of a vegetarian diet on health, its influence on the quality of life of the individuals who follow it still needs to be properly investigated. Quality of life relates to a subjective perception of well-being and functionality, and encompasses four main life domains: physical, psychological, social, and environmental. The adoption of a vegetarian diet, despite being a dietary pattern, could potentially influence and be influenced by all of these domains, either positively or negatively. This review aims to present an overview of the background, conceptualization, features, and potential effects of vegetarianism in all quality of life domains. The choice of adopting a vegetarian diet could have positive outcomes, such as better physical health, positive feelings related to the adoption of a morally correct attitude, an increased sense of belonging (to a vegetarian community), and lower environmental impact. Other factors, however, could have a negative impact on the quality of life of those choosing to abstain from meats or other animal products, especially when they go beyond one's control. These include the environment, the social/cultural group in which a person is inserted, gender-based differences, economic aspects, and a limited access to a wide variety of plant-based foods. It is important to understand all the effects of adopting a vegetarian diet-beyond its nutritional aspects. Not only do studies in this area provide more consistent data, but they may also contribute to mitigating all factors that might prevent individuals from adopting a vegetarian diet, or that may have a negative impact on the quality of life of those who already follow it.