Plant-based and Early Time-restricted Eating for Prevention and Treatment of Type 2 Diabetes in Adults: A Narrative Review.

Type 2 diabetes (T2D) is a significant public health challenge for which effective lifestyle interventions are needed. A growing body of evidence supports the use of both plant-based eating patterns and early time-restricted eating (eTRE) for the prevention and treatment of T2D, but research has not yet explored the potential of these dietary strategies in combination. In this narrative review, we assessed the evidence by which plant-based diets, in conjunction with eTRE, could support T2D care. The electronic databases MEDLINE and the Web of Science were searched for relevant articles published throughout the last decade. Observational research has shown that healthy plant-based eating patterns and eTRE are associated with reductions in T2D risk. Interventional trials demonstrated that plant-based diets promote improvements in glycated hemoglobin, insulin resistance, glycemic management, and cardiometabolic risk factors. These changes may be mediated, in part, by reductions in oxidative stress, dietary acid load, and hepatocellular and intramyocellular lipids. The eTRE strategies were also shown to improve insulin resistance and glycemic management, and mechanisms of action included enhanced regulation of circadian rhythm and increased metabolic flexibility. Integrating these dietary strategies may produce additive benefits, mediated by reduced visceral adiposity and beneficial shifts in gut microbiota composition. However, potential barriers to concurrent implementation of these interventions may exist, including social challenges, scheduling constraints, and tolerance. Prospective trials are needed to examine their acceptability and clinical effects.

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.

Common Beans as a Source of Amino Acids and Cofactors for Collagen Biosynthesis.

Common beans (Phaseolus vulgaris L.) are widely consumed in diets all over the world and have a significant impact on human health. Proteins, vitamins, minerals, phytochemicals, and other micro- and macronutrients are abundant in these legumes. On the other hand, collagens, the most important constituent of extracellular matrices, account for approximately 25-30 percent of the overall total protein composition within the human body. Hence, the presence of amino acids and other dietary components, including glycine, proline, and lysine, which are constituents of the primary structure of the protein, is required for collagen formation. In this particular context, protein quality is associated with the availability of macronutrients such as the essential amino acid lysine, which can be acquired from meals containing beans. Lysine plays a critical role in the process of post-translational modifications facilitated with enzymes lysyl hydroxylase and lysyl oxidase, which are directly involved in the synthesis and maturation of collagens. Furthermore, collagen biogenesis is influenced by the cellular redox state, which includes important minerals and bioactive chemicals such as iron, copper, and certain quinone cofactors. This study provides a novel perspective on the significant macro- and micronutrients present in Phaseolus vulgaris L., as well as explores the potential application of amino acids and cofactors derived from this legume in the production of collagens and bioavailability. The utilization of macro- and micronutrients obtained from Phaseolus vulgaris L. as a protein source, minerals, and natural bioactive compounds could optimize the capacity to promote the development and durability of collagen macromolecules within the human body.

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.

Protein Quality Changes of Vegan Day Menus with Different Plant Protein Source Compositions.

To underline the importance of protein quality in plant-based diets, we estimated the protein quality of different exclusively plant-protein-based day menus that are based on the "planetary health diet" developed by the EAT-Lancet Commission. PDCAAS and DIAAS were used to estimate the protein quality (PQ) and fulfilling of the amino acid recommendation for adults in vegan daily menus based on the planetary health diet: 2 days with only low-quality (LQ) protein sources and 2 days with low + high-quality (HQ) protein sources. The protein quality of Day 1LQ (DIAAS 76, PDCAAS 88) was increased by the addition of high-quality protein sources (HQPS): Day 1HQ (DIAAS 94, PDCAAS 98). Day 2LQ had a low PQ (DIAAS 71, PDCAAS 74), but when HQPS were used (Day 2HQ), the PQ increased (DIAAS 83, PDCAAS 88). Scenarios (day 1HQ, day 1LQ, and day 2 HQ) were classified as of good PQ. However, day 1LQ had a low protein quality. Consuming HQPS in a vegan diet can help to fulfil the recommendation of essential amino acids. This work served to understand and apply methods to estimate protein quality that can be applied to optimize protein mixtures to fulfil amino acid requirements in the future.

Knowledge on the Complementary Feeding of Infants Older than Six Months among Mothers Following Vegetarian and Traditional Diets.

Solid foods should be introduced not later than the age of six months, regardless of whether the family adheres to a traditional, vegetarian, or vegan diet. The aim of this study was to compare the knowledge on the complementary feeding of infants older than six months among mothers who adhere to traditional and vegetarian diets and to identify problems that require the assistance of a dietician. A total of 251 mothers of children aged 10-12 months participated in the study. Only 10% of vegetarian mothers declared that they had placed their children on a vegetarian diet, whereas 36 mothers adhered to a lacto-ovo-vegetarian diet during complementary feeding in the first year of life. Mothers adhering to a traditional diet were characterized by lower levels of knowledge (4.1 ± 2.3 points) than vegetarian mothers (5.3 ± 2.1 points). Mothers following a traditional diet were more likely to indicate a higher than recommended number of daily meals (OR = 1.76; Cl: 1.31-1.97, p < 0.001). Significant differences were noted in the respondents' adherence to the BLW method, which was more readily implemented by vegan (p < 0.05) and lacto-vegetarian (p < 0.05) mothers and was least popular among mothers following a traditional diet (OR = 0.81; CI: 0.66-1.23, p < 0.04). Vegetarian mothers unnecessarily delayed the introduction of gluten and potentially allergizing foods to the children's diets, sometimes even past the age of 12 months.

Intake and adequacy of the vegan diet. A systematic review of the evidence.

BACKGROUND: Vegan diets, where animal- and all their by-products are excluded from the diet, have gained popularity, especially in the last decade. However, the evaluation of this type of diet has not been well addressed in the scientific literature. This study aimed to investigate the adequacy of vegan diets in European populations and of their macro- and micronutrient intakes compared to World Health Organization recommendations. METHODS: A systematic search in PubMed, Web of Science, IBSS, Cochrane library and Google Scholar was conducted and 48 studies (12 cohorts and 36 cross-sectional) were included. RESULTS: Regarding macronutrients, vegan diets are lower in protein intake compared with all other diet types. Veganism is also associated with low intake of vitamins B2, Niacin (B3), B12, D, iodine, zinc, calcium, potassium, selenium. Vitamin B12 intake among vegans is significantly lower (0.24-0.49 µg, recommendations are 2.4 µg) and calcium intake in the majority of vegans was below recommendations (750 mg/d). No significant differences in fat intake were observed. Vegan diets are not related to deficiencies in vitamins A, B1, Β6, C, E, iron, phosphorus, magnesium, copper and folate and have a low glycemic load. CONCLUSIONS: Following a vegan diet may result in deficiencies in micronutrients (vitamin B12, zinc, calcium and selenium) which should not be disregarded. However, low micro- and macronutrient intakes are not always associated with health impairments. Individuals who consume a vegan diet should be aware of the risk of potential dietary deficiencies.

Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study.

BACKGROUND: There is limited prospective evidence on possible differences in fracture risks between vegetarians, vegans, and non-vegetarians. We aimed to study this in a prospective cohort with a large proportion of non-meat eaters. METHODS: In EPIC-Oxford, dietary information was collected at baseline (1993-2001) and at follow-up (≈ 2010). Participants were categorised into four diet groups at both time points (with 29,380 meat eaters, 8037 fish eaters, 15,499 vegetarians, and 1982 vegans at baseline in analyses of total fractures). Outcomes were identified through linkage to hospital records or death certificates until mid-2016. Using multivariable Cox regression, we estimated the risks of total (n = 3941) and site-specific fractures (arm, n = 566; wrist, n = 889; hip, n = 945; leg, n = 366; ankle, n = 520; other main sites, i.e. clavicle, rib, and vertebra, n = 467) by diet group over an average of 17.6 years of follow-up. RESULTS: Compared with meat eaters and after adjustment for socio-economic factors, lifestyle confounders, and body mass index (BMI), the risks of hip fracture were higher in fish eaters (hazard ratio 1.26; 95% CI 1.02-1.54), vegetarians (1.25; 1.04-1.50), and vegans (2.31; 1.66-3.22), equivalent to rate differences of 2.9 (0.6-5.7), 2.9 (0.9-5.2), and 14.9 (7.9-24.5) more cases for every 1000 people over 10 years, respectively. The vegans also had higher risks of total (1.43; 1.20-1.70), leg (2.05; 1.23-3.41), and other main site fractures (1.59; 1.02-2.50) than meat eaters. Overall, the significant associations appeared to be stronger without adjustment for BMI and were slightly attenuated but remained significant with additional adjustment for dietary calcium and/or total protein. No significant differences were observed in risks of wrist or ankle fractures by diet group with or without BMI adjustment, nor for arm fractures after BMI adjustment. CONCLUSIONS: Non-meat eaters, especially vegans, had higher risks of either total or some site-specific fractures, particularly hip fractures. This is the first prospective study of diet group with both total and multiple specific fracture sites in vegetarians and vegans, and the findings suggest that bone health in vegans requires further research.

The Effects of Vegetarian and Vegan Diet during Pregnancy on the Health of Mothers and Offspring.

Vegetarian and vegan diets have increased worldwide in the last decades, according to the knowledge that they might prevent coronary heart disease, cancer, and type 2 diabetes. Althought plant-based diets are at risk of nutritional deficiencies such as proteins, iron, vitamin D, calcium, iodine, omega-3, and vitamin B12, the available evidence shows that well planned vegetarian and vegan diets may be considered safe during pregnancy and lactation, but they require a strong awareness for a balanced intake of key nutrients. A review of the scientific literature in this field was performed, focusing specifically on observational studies in humans, in order to investigate protective effects elicited by maternal diets enriched in plant-derived foods and possible unfavorable outcomes related to micronutrients deficiencies and their impact on fetal development. A design of pregestational nutrition intervention is required in order to avoid maternal undernutrition and consequent impaired fetal growth.

Developing a Food Exchange System for Meal Planning in Vegan Children and Adolescents.

Vegan diets in children need to be adequately planned so they can safely meet children's requirements for growth and development. Adequate and realistic meal planning guidelines should not be difficult to achieve, thanks to the increasing number and availability of natural and fortified vegan foods, which can help children to meet all their nutrients requirements. In order to ensure an adequate supply of key nutrients, families and health professionals need accurate, reliable, and easy-to-use meal planning tools. The aim of this article is to provide a practical approach system to meal planning, based on the same food exchange methodology that has been already published in adults. Daily portions of each food exchange group have been calculated so the resulting menu provides at least 90% of the Dietary Reference Intakes (DRIs) of protein, iron, zinc, calcium, and n-3 fatty acids for each age group, sex, and physical activity level. These diets do not provide enough vitamin B-12 and vitamin D. Although fortified plant drinks, breakfast cereals or plant protein-rich products could provide variable amounts of these two vitamins, B12 supplementation is always recommended and vitamin D supplementation should be considered whenever sun exposure is limited. This tool can be used to plan healthful and balanced vegan diets for children and adolescents.

Vegan Nutrition for Mothers and Children: Practical Tools for Healthcare Providers.

As the number of subjects choosing vegan diets increases, healthcare providers must be prepared to give the best advice to vegan patients during all stages of life. A completely plant-based diet is suitable during pregnancy, lactation, infancy, and childhood, provided that it is well-planned. Balanced vegan diets meet energy requirements on a wide variety of plant foods and pay attention to some nutrients that may be critical, such as protein, fiber, omega-3 fatty acids, iron, zinc, iodine, calcium, vitamin D, and vitamin B12. This paper contains recommendations made by a panel of experts from the Scientific Society for Vegetarian Nutrition (SSNV) after examining the available literature concerning vegan diets during pregnancy, breastfeeding, infancy, and childhood. All healthcare professionals should follow an approach based on the available evidence in regard to the issue of vegan diets, as failing to do so may compromise the nutritional status of vegan patients in these delicate periods of life.

Turning the Waiting Room into a Classroom: Weekly Classes Using a Vegan or a Portion-Controlled Eating Plan Improve Diabetes Control in a Randomized Translational Study.

BACKGROUND: In research settings, plant-based (vegan) eating plans improve diabetes management, typically reducing weight, glycemia, and low-density lipoprotein (LDL) cholesterol concentrations to a greater extent than has been shown with portion-controlled eating plans. OBJECTIVE: The study aimed to test whether similar benefits could be found using weekly nutrition classes in a typical endocrinology practice, hypothesizing that a vegan eating plan would improve glycemic control, weight, lipid concentrations, blood pressure, and renal function and would do so more effectively than a portion-controlled eating plan. DESIGN: In a 20-week trial, participants were randomly assigned to a low-fat vegan or portion-controlled eating plan. PARTICIPANTS/SETTING: Individuals with type 2 diabetes treated in a single endocrinology practice in Washington, DC, participated (45 starters, 40 completers). INTERVENTION: Participants attended weekly after-hours classes in the office waiting room. The vegan plan excluded animal products and added oils and favored low-glycemic index foods. The portion-controlled plan included energy intake limits for weight loss (typically a deficit of 500 calories/day) and provided guidance on portion sizes. MAIN OUTCOME MEASURES: Body weight, hemoglobin A1c (HbA1c), plasma lipids, urinary albumin, and blood pressure were measured. STATISTICAL ANALYSES PERFORMED: For normally distributed data, t tests were used; for skewed outcomes, rank-based approaches were implemented (Wilcoxon signed-rank test for within-group changes, Wilcoxon two-sample test for between-group comparisons, and exact Hodges-Lehmann estimation to estimate effect sizes). RESULTS: Although participants were in generally good metabolic control at baseline, body weight, HbA1c, and LDL cholesterol improved significantly within each group, with no significant differences between the two eating plans (weight: -6.3 kg vegan, -4.4 kg portion-controlled, between-group P=0.10; HbA1c, -0.40 percentage point in both groups, P=0.68; LDL cholesterol -11.9 mg/dL vegan, -12.7 mg/dL portion-controlled, P=0.89). Mean urinary albumin was normal at baseline and did not meaningfully change. Blood pressure changes were not significant. CONCLUSIONS: Weekly classes, integrated into a clinical practice and using either a low-fat vegan or portion-controlled eating plan, led to clinical improvements in individuals with type 2 diabetes.

Examining the Impact of Adherence to a Vegan Diet on Acid-Base Balance in Healthy Adults.

Acidogenic diets, commonly measured by the potential renal acid load (PRAL), have been linked with metabolic diseases including insulin resistance, hepatic dysfunction, and cardiometabolic risk. Vegan diets are linked to low dietary acid loads, but the degree of adherence to a vegan diet to demonstrate this benefit is unknown. This study compared the change in PRAL and urine pH of omnivores who followed a vegan diet for either 2, 3, or 7 days over one week. Healthy adults were recruited from a campus population and randomly assigned to one of the three groups: VEG7 (vegan diet followed for seven consecutive days); VEG3 (vegan diet followed for three evenly spaced days over one week); or VEG2 (vegan diet followed for two evenly spaced days over one week). Gender, age, and body mass index did not differ between groups (overall: 21.8 ± 2.4 y and 24.4 ± 5.6 kg/m2). Following the one week intervention, outcome measures did not vary between the VEG2 and VEG3 groups, and these groups were collapsed for the final analyses. The 24-h urine pH was raised after seven consistent days of vegan diet adherence and was unchanged after 2-3 days of vegan diet adherence over the course of a week (+0.52 ± 0.69 and -0.02 ± 0.56 respectively, p = 0.048). However, dietary PRAL scores fell significantly in both dietary groups during the 7-day trial. Since low dietary PRAL scores have been related to improve metabolic parameters, adoption of a vegan diets for several days per week should be explored as a diet strategy to lower disease risk.

Consumption of a high-fat meal containing cheese compared with a vegan alternative lowers postprandial C-reactive protein in overweight and obese individuals with metabolic abnormalities: a randomised controlled cross-over study.

Dietary recommendations suggest decreased consumption of SFA to minimise CVD risk; however, not all foods rich in SFA are equivalent. To evaluate the effects of SFA in a dairy food matrix, as Cheddar cheese, v. SFA from a vegan-alternative test meal on postprandial inflammatory markers, a randomised controlled cross-over trial was conducted in twenty overweight or obese adults with metabolic abnormalities. Individuals consumed two isoenergetic high-fat mixed meals separated by a 1- to 2-week washout period. Serum was collected at baseline, and at 1, 3 and 6 h postprandially and analysed for inflammatory markers (IL-6, IL-8, IL-10, IL-17, IL-18, TNFα, monocyte chemotactic protein-1 (MCP-1)), acute-phase proteins C-reactive protein (CRP) and serum amyloid-A (SAA), cellular adhesion molecules and blood lipids, glucose and insulin. Following both high-fat test meals, postprandial TAG concentrations rose steadily (P < 0·05) without a decrease by 6 h. The incremental AUC (iAUC) for CRP was significantly lower (P < 0·05) in response to the cheese compared with the vegan-alternative test meal. A treatment effect was not observed for any other inflammatory markers; however, for both test meals, multiple markers significantly changed from baseline over the 6 h postprandial period (IL-6, IL-8, IL-18, TNFα, MCP-1, SAA). Saturated fat in the form of a cheese matrix reduced the iAUC for CRP compared with a vegan-alternative test meal during the postprandial 6 h period. The study is registered at clinicaltrials.gov under NCT01803633.