A Vegan Diet Is Associated with a Significant Reduction in Dietary Acid Load: Post Hoc Analysis of a Randomized Controlled Trial in Healthy Individuals

The composition of diet strongly affects acid–base homeostasis. Western diets abundant in acidogenic foods (meat and cheese) and deficient in alkalizing foods (fruits and vegetables) increase dietary acid load (DAL). A high DAL has been associated with numerous health repercussions, including cardiovascular disease and type-2-diabetes. Plant-based diets have been associated with a lower DAL; however, the number of trials exploring this association is limited. This randomized-controlled trial sought to examine whether an isocaloric vegan diet lowers DAL as compared to a meat-rich diet. Forty-five omnivorous individuals were randomly assigned to a vegan diet (n = 23) or a meat-rich diet (n = 22) for 4 weeks. DAL was determined using potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores at baseline and after 3 and 4 weeks, respectively. After 3 weeks, median PRAL (−23.57 (23.87)) and mean NEAPR (12.85 ± 19.71) scores were significantly lower in the vegan group than in the meat-rich group (PRAL: 18.78 (21.04) and NEAPR: 60.93 ± 15.51, respectively). Effects were mediated by a lower phosphorus and protein intake in the vegan group. Our study suggests that a vegan diet is a potential means to reduce DAL, whereas a meat-rich diet substantially increases the DAL burden.

Body composition assessment of vegetarian-vegan and omnivore young women – an exploratory study

Diet is commonly accepted as a determinant of body composition, especially when related to specific lifestyles. Vegetarian-vegan diets, which involve a reduction or elimination of animal product consumption, are believed to be more “healthy,” facilitating weight control and reducing the incidence and clinical course of different diseases, in particular those related to overweight and obesity. Global reviews and metanalysis on these issues, however, are still insufficient. Our preliminary approach addresses the total body composition differences among vegetarians-vegans and omnivorous individuals. This cross-sectional study involved ten healthy women, five vegetarian-vegan, and five omnivores (mean 28.10 years old). Body composition was assessed using a dual-energy x-ray absorptiometry (DXA Lunar Prodigy Advance - General Electric Healthcare®). Other general and sociodemographic variables were also collected by trained dietitians. Our results have shown that the vegetarian-vegan group had a non-significantly lower volume of all types of body mass (total bone, fat, lean, tissue, and fat-free) evaluated. Additionally, the vegetarian-vegan group presented higher values of visceral adipose tissue and subcutaneous adipose tissue (286.20 and 11138.40 cm3, respectively, p > 0.05) compared to the omnivore group. These differences will be further confirmed in subsequent studies.

Abstract 15565: Long-term Dietary and Weight Changes Following a Short-term Dietary Intervention Study: 4-year Follow-up of the Evade Cad Trial

Introduction: The randomized EVADE CAD trial demonstrated greater reduction in high sensitivity C-reactive protein and LDL-cholesterol with a vegan vs. AHA-recommended diet in patients with coronary artery disease on guideline-directed medical therapy. The 8-week intervention included provision of groceries, cooking tools, and regular contact with a registered dietitian. Methods: Trial participants underwent telephone follow-up to obtain self-reported dietary adherence, 24-hour dietary recall, self-reported weight, and major adverse cardiovascular events (MACE). Supporting medical documents for MACE were reviewed by investigators. Results: Two participants in the vegan arm withdrew during the trial leaving 98 participants available for follow-up. The vegan group reported significantly lower dietary adherence at all follow-ups when compared to the AHA group; however, adherence rates were numerically higher in both groups when assessed by 24-hour dietary recall vs. self-report (F1A-B). The two groups did not differ in self-reported rating of the healthiness of their current diet (F1C). Both groups continued to have significantly lower weight when compared to baseline up to 3 years follow-up, but only the vegan group remained lower at year 4. Percent weight lost from baseline did not differ between groups. Cumulative MACE incidence also did not differ between groups (F2). Conclusions: Although the vegan diet was not sustainable long-term when compared to the AHA-recommended diet, both groups did not differ in self-reported rating of the healthiness of their current diet or incidence of MACE and had sustained weight loss after the active intervention was complete.

Effects of a Low-Fat Vegan Diet on Gut Microbiota in Overweight Individuals and Relationships with Body Weight, Body Composition, and Insulin Sensitivity. A Randomized Clinical Trial

Diet modulates gut microbiota and plays an important role in human health. The aim of this study was to test the effect of a low-fat vegan diet on gut microbiota and its association with weight, body composition, and insulin resistance in overweight men and women. We enrolled 168 participants and randomly assigned them to a vegan (n = 84) or a control group (n = 84) for 16 weeks. Of these, 115 returned all gut microbiome samples. Gut microbiota composition was assessed using uBiome Explorer™ kits. Body composition was measured using dual energy X-ray absorptiometry. Insulin sensitivity was quantified with the predicted clamp-derived insulin sensitivity index from a standard meal test. Repeated measure ANOVA was used for statistical analysis. Body weight decreased in the vegan group (treatment effect −5.9 kg [95% CI, −7.0 to −4.9 kg]; p < 0.001), mainly due to a reduction in fat mass (−3.9 kg [95% CI, −4.6 to −3.1 kg]; p < 0.001) and in visceral fat (−240 cm3 [95% CI, −345 to −135 kg]; p < 0.001). PREDIcted M, insulin sensitivity index (PREDIM) increased in the vegan group (treatment effect +0.83 [95% CI, +0.48 to +1.2]; p < 0.001). The relative abundance of Faecalibacterium prausnitzii increased in the vegan group (+5.1% [95% CI, +2.4 to +7.9%]; p < 0.001) and correlated negatively with changes in weight (r = −0.24; p = 0.01), fat mass (r = −0.22; p = 0.02), and visceral fat (r = −0.20; p = 0.03). The relative abundance of Bacteroides fragilis decreased in both groups, but less in the vegan group, making the treatment effect positive (+18.9% [95% CI, +14.2 to +23.7%]; p < 0.001), which correlated negatively with changes in weight (r = −0.44; p < 0.001), fat mass (r = −0.43; p < 0.001), and visceral fat (r = −0.28; p = 0.003) and positively with PREDIM (r = 0.36; p < 0.001), so a smaller reduction in Bacteroides fragilis was associated with a greater loss of body weight, fat mass, visceral fat, and a greater increase in insulin sensitivity. A low-fat vegan diet induced significant changes in gut microbiota, which were related to changes in weight, body composition, and insulin sensitivity in overweight adults, suggesting a potential use in clinical practice.

A Vegan Athlete’s Heart—Is It Different? Morphology and Function in Echocardiography

Plant-based diets are a growing trend, including among athletes. This study compares the differences in physical performance and heart morphology and function between vegan and omnivorous amateur runners. A study group and a matched control group were recruited comprising N = 30 participants each. Eight members of the study group were excluded, leaving N = 22 participants. Members of both groups were of similar age and trained with similar frequency and intensity. Vegans displayed a higher VO2max (54.08 vs. 50.10 mL/kg/min, p < 0.05), which correlated positively with carbohydrate intake (ρ = 0.52) and negatively with MUFA (monounsaturated fatty acids) intake (ρ = −0.43). The vegans presented a more eccentric form of remodelling with greater left ventricular end diastolic diameter (LVEDd, 2.93 vs. 2.81 cm/m2, p = 0.04) and a lower relative wall thickness (RWT, 0.39 vs. 0.42, p = 0.04) and left ventricular mass (LVM, 190 vs. 210 g, p = 0.01). The left ventricular mass index (LVMI) was similar (108 vs. 115 g/m2, p = NS). Longitudinal strain was higher in the vegan group (−20.5 vs. −19.6%, p = 0.04), suggesting better systolic function. Higher E-wave velocities (87 vs. 78 cm/s, p = 0.001) and E/e′ ratios (6.32 vs. 5.6, p = 0.03) may suggest better diastolic function in the vegan group. The results demonstrate that following a plant-based diet does not impair amateur athletes’ performance and influences both morphological and functional heart remodelling. The lower RWT and better LV systolic and diastolic function are most likely positive echocardiographic findings.

Differences in Taste Sensitivity between Vegans and Non-Vegetarians in Palembang, Indonesia

Introduction: Many studies have shown that nutritional deficiencies can affect taste sensitivity. One group at high risk of nutritional deficiencies is vegans. Objective: The aim of the present study was to investigate the differences in taste sensitivity between vegans and non-vegetarians in Palembang, Indonesia. Methods: This was an observational analytic study with a quasi-experimental approach. A total of 60 subjects aged 21–45 years were included in this study. The subjects were divided into two groups: vegans (n = 30) and non-vegetarians (n = 30). Taste sensitivity was measured using the filter paper disc method. Five taste qualities (sweet, salt, sour, bitter, and umami) were tested using four different concentrations for each taste quality. The lowest concentrations identified correctly by the subjects were recorded as the taste sensitivity scores. The taste sensitivity scores were subsequently summed to form the taste scores. The data were analyzed using the Mann–Whitney U test. Results: The mean values of the sweet, bitter, and umami taste sensitivity scores and the taste score in the vegan group were lower than those in the non-vegetarian group. The mean value of the salt taste sensitivity score in the vegan group was higher than that of the non-vegetarian group, while the mean value in the sour taste sensitivity score was the same for both groups. There were no significant differences in the sweet, salt, sour, bitter, and umami taste sensitivity scores and taste scores of the vegan and non-vegetarian groups (p>0.05). Conclusion: The vegans and non-vegetarians in Palembang in this study have differences in taste sensitivity, but these results are not significant.

The influence of plant-based nutrition and level of oestrogen on life satisfaction

Previous studies have shown that people benefit more from vegetarian or vegan diets than from an omnivorous diet, not only in physical but also in mental health. Studies have also reported substantial evidence that particular disorders can be triggered by preferred food choices. For example, consumption of animal products increases the intake of arachidonic acid which can induce depressive moods. On the other hand, nutrition can have positive effects, e.g. polyunsaturated N-3 fatty acids have several somatic health benefits not only on cardiovascular diseases, but also on depression. Similarly, a diet with a high content of tryptophan (a serotonin predecessor) can change mood by altering the synthesis of different neurotransmitters. In this pilot study, (i) omnivores (n=45), (ii) vegetarians (n=13) and (iii) vegans (n=7) were compared for their levels of satisfaction in everyday life, as measured on the Oxford Happiness Scale. The effect of oestrogen was analysed as a confounding variable. Between the three styles of nutrition, only small differences were found. All groups achieved an average of more than 4 points on a 6-stage Likert-scale (1=not happy, 6 = very happy), which lies in the range of moderately happy. The mean score of all three groups was 4.30 ±0.84. The difference between the omnivore, (4.23 ±0.69) and the vegetarian groups, (4.29 ±1.24) was very small, but the vegan group achieved a score well above 5, (5.20 ±0.17). In an ANCOVA, the effect of nutrition style on happiness was close to being significant, [p=0.066]. In addition, estimated oestrogen level had significant effects on satisfaction in everyday life, [p=0.047]. Conclusion: Further research on a larger sample is justified to determine if life satisfaction is influenced by nutrition style when controlled for oestrogen levels.

A Plant-Based High-Carbohydrate, Low-Fat Diet in Overweight Individuals in a 16-Week Randomized Clinical Trial: The Role of Carbohydrates

The effects of carbohydrates on body weight and insulin sensitivity are controversial. In this 16-week randomized clinical trial, we tested the role of a low-fat, plant-based diet on body weight, body composition and insulin resistance. As a part of this trial, we investigated the role of changes in carbohydrate intake on body composition and insulin resistance. Participants (n = 75) were randomized to follow a plant-based high-carbohydrate, low-fat (vegan) diet (n = 38) or to maintain their current diet (n = 37). Dual-energy X-ray absorptiometry was used to measure body composition. Insulin resistance was assessed with the Homeostasis Model Assessment (HOMA-IR) index. A repeated measure ANOVA model was used to test the between-group differences from baseline to 16 weeks. A linear regression model was used to test the relationship between carbohydrate intake, and body composition and insulin resistance. Weight decreased significantly in the vegan group (treatment effect −6.5 [95% CI −8.9 to −4.1] kg; Gxt, p < 0.001). Fat mass was reduced in the vegan group (treatment effect −4.3 [95% CI −5.4 to −3.2] kg; Gxt, p < 0.001). HOMA-IR was reduced significantly in the vegan group (treatment effect −1.0 [95% CI −1.2 to −0.8]; Gxt, p = 0.004). Changes in consumption of carbohydrate, as a percentage of energy, correlated negatively with changes in BMI (r = −0.53, p < 0.001), fat mass (r = −0.55, p < 0.001), volume of visceral fat (r = −0.35, p = 0.006), and HOMA (r = −0.27, p = 0.04). These associations remained significant after adjustment for energy intake. Changes in consumption of total and insoluble fiber correlated negatively with changes in BMI (r = −0.43, p < 0.001; and r = −0.46, p < 0.001, respectively), fat mass (r = −0.42, p < 0.001; and r = −0.46, p < 0.001, respectively), and volume of visceral fat (r = −0.29, p = 0.03; and r = −0.32, p = 0.01, respectively). The associations between total and insoluble fiber and changes in BMI and fat mass remained significant even after adjustment for energy intake. Increased carbohydrate and fiber intake, as part of a plant-based high-carbohydrate, low-fat diet, are associated with beneficial effects on weight, body composition, and insulin resistance.

STUDY ON THE PREDICTION OF HYPERGLYCEMIA ACCORDING TO THE DURATION OF VEGAN DIET IN FEMALE

Objectives: To determine the prediction of hyperglycemia according to the duration of vegan diet in female. Materials and Methods: 144 female vegans aged from 20-75 with duration of vegan diet ranged 1070 years, mean 27.8±15.9 years that were screened for carbohydrate dysmetabolism. They were compared with 68 women with aged from 22-84 non-vegetarian diet. Results: The average fasting glucose in female Vegan group was higher than in control group (5.00 ±1.40 vs 4.67 ± 0.98 mmol/l, p<0.05). The prevalence of hyperglycemia (based on fasting glucose) in female Vegan group was higher than in control group (13.2% vs 10.3%, p < 0.05). Especially, there were significant differences in HbA1c levels between two groups. The average HbA1c in female Vegan group was higher than in control group (5.9 ±0.9 so với 4.3 ± 0.90%, p < 0.05). The prevalence of hyperglycemia (based on HbA1c) in vegan group was higher than in control group (45.1% vs 13.2%, p < 0.05); prediabetes was 34% in Vegan group and 10.3% in control group. There were correlations between duration of vegan diet and FG (r = 0.312), HbA1c (r = 0.403), in which the duration of vegan diet was considered as an independent risk factor for hyperglycemia. Prediabetes was 18 yrs and diabetes was 42 yrs of vegan diet duration. Conclusions: Vegan diets in women can predict hyperglycemia after an 18-year period. Key words: duration of vegan diet, hyperglycemia, HbA1c