Vegetarian diets and sports : nutritional status and exercise performance in recreational runners

Background and aim: The proportion of vegetarian diets has increased in recent years. The beneficial effects of a lacto-ovo vegetarian diet on various diseases such as type 2 diabetes and cardiometabolic disorders are well documented. In contrast, there are also potentially critical nutrients such as vitamin B12, D, and iron. The popularity of vegetarian diets is increasing in endurance sports as well. However, previous studies investigating the relationship between vegetarian diets and sports are outdated, questionnaire-based and did not include nutritional or sports medical diagnostics, had a very low sample size or included only vegetarians and omnivores. There are no significant data on vegan athletes. In addition, data on exercise-induced metabolic changes do not exist. The validity of the current knowledge is therefore low. As a result, the aim of this thesis was to study the nutrient intake, status of selected biomarkers, exercise capacity and exercise-induced changes in energy metabolism (sirtuins), oxidative stress (malondialdehyde), amino acid profile (AA profile), and nitric oxide (NO) (nitrate, nitrite). Methods: In a cross-sectional study 81 ambitious male and female recreational runners (18-35 years, BMI 20-25 kg / m², 2-5 training sessions per week) with an omnivorous (OMN, n=27), lacto-ovo vegetarian (LOV, n=26) or vegan (VEG, n=28) diet were included in the study and were matched according to age and gender. Initially, anthropometric examinations, recording of nutrient intake (incl. supplements) based on 3-day dietary records as well as fasting blood samples to determine the status of vitamin B12, D, and iron, and folic acid as well as of zinc, magnesium, and calcium, were carried out. In addition, performance diagnostics and measurement of the lactate and glucose concentration by means of an incremental step test until exhaustion took place. The short-term food intake was conducted on the day of the performance diagnostics using a 24-hours dietary recall. In addition, blood samples were taken before and after exercise to analyze exercise-induced changes in sirtuins, malondialdehyde, AA profile, nitrate, and nitrite. Results: On average, dietary nutrient intake was adequate for all three groups, which was in part due to supplementation. Despite partially quantitatively different nutrient intake, a comparable and adequate status of vitamin B12, D, and iron biomarkers could be determined. The performance diagnostics revealed no differences between the groups in maximum power output related to body weight (OMN: 4.15 ± 0.48, LOV: 4.20 ± 0.47, VEG: 4.16 ± 0.55 watt/kg BW, p=0.917) and lactate and glucose concentrations. In addition, the study showed that the groups differ in terms of oxidative stress, NO metabolism, and AA profile. Exercise induced an increase in MDA in all three groups, no significant changes in nitrate and nitrite, and comparable increases in alanine, while there were differences in AA metabolism as well. Conclusion: Ambitious recreational runners with vegetarian diets have an adequate status even with otherwise critical nutrients and thus show a high health awareness. Especially in VEG, there seem to exist adaptational mechanisms in energy metabolism, as shown by sirtuin activity and AA metabolism. However, these only partially affect performance. Factors such as exercise and genetic aspects seem to have a greater impact on performance than avoiding meat. In addition, it can be assumed that increased antioxidant intake has no additive effects on exercise-induced oxidative stress. The study shows that both vegetarian and vegan diets are an adequate alternative for ambitious recreational athletes. Further studies are needed to examine the influence of vegetarian diets on health and physical performance

Plant-based diets and cardiovascular risk factors: a comparison of flexitarians, vegans and omnivores in a cross-sectional study

Background: The growing trend towards conscious and sustainable dietary choices has led to increased adoption of flexitarian diets, characterised by plant-based eating habits with occasional consumption of meat and processed meat products. However, the cardiovascular disease (CVD) risk factors associated with flexitarian diets compared to both vegans and omnivores remain underexplored. Methods: In this cross-sectional study, 94 healthy participants aged 25–45 years, categorized into long-term flexitarians (FXs ≤ 50 g/day of meat and meat products, n = 32), vegans (Vs, no animal products, n = 33), and omnivores (OMNs ≥ 170 g/day of meat and meat products, n = 29) were included. Various CVD risk factors were measured, including fasting blood samples for metabolic biomarkers, body composition analysis via bioimpedance, blood pressure measurements, arterial stiffness evaluated through pulse wave velocity (PWV) and metabolic syndrome (MetS) severity was determined using browser-based calculations (MetS-scores). Dietary intake was assessed using a Food Frequency Questionnaire (FFQ), diet quality was calculated with the Healthy Eating Index-flexible (HEI-Flex), while physical activity levels were recorded using the validated Freiburger questionnaire. Results: The data showed that FXs and Vs had more beneficial levels of insulin, triglycerides, total cholesterol, and LDL cholesterol compared to OMNs. Notably, FXs revealed the most favorable MetS-score results based on both BMI and waistline, and better PWV values than Vs and OMNs. In addition, FXs and Vs reported higher intake rates of vegetables, fruit, nuts/seeds and plant-based milk alternatives. Conclusion: The flexitarian diet appears to confer cardiovascular benefits. While Vs had the most favorable results overall, this study supports that reducing meat and processed meat products intake, as in flexitarianism, may contribute to CVD risk factor advantages

Nutritional status of flexitarians compared to vegans and omnivores - a cross-sectional pilot study

Background: In the Western world, there has been a notable rise in the popularity of plant-based, meat-reduced flexitarian diets. Nevertheless, there is insufficient data on the nutritional status of individuals following this dietary pattern. The aim of this study was to investigate the intake and endogenous status of various nutrients in a healthy German adult study population consisting of flexitarians (FXs), vegans (Vs) and omnivores (OMNs). Methods: In this cross-sectional study, dietary intake of 94 non-smoking adults (32 FXs, 33 Vs, 29 OMNs) between 25 and 45 years of age was assessed using 3-day dietary records. In addition, blood samples were collected to determine different endogenous nutrient status markers. Results: 32%, 82% and 24% of the FXs, Vs, and OMNs respectively reported using dietary supplements. In the FXs, intake of total energy as well as macronutrients and most micronutrients were within the reference range. FXs had higher intakes of fiber, retinol-equ., ascorbic acid, folate-equ., tocopherol-equ., calcium, and magnesium compared to OMNs. However, cobalamin intake in FXs (2.12 µg/d) was below the reference (4 µg/d). Based on 4cB12, 13% of FXs showed a cobalamin undersupply [< -0.5 to -2.5] compared to 10% of OMNs, and 9% of Vs. The median 25(OH)D serum concentrations in FXs, Vs and OMNs were 46.6, 55.6, and 59.6 nmol/L. The prevalence of an insufficient/deficient vitamin-D status [< 49.9 nmol 25(OH)D/L] was highest in FXs (53%), followed by Vs (34%) and OMNs (27%). In FXs and Vs, the supplement takers had better cobalamin and vitamin-D status than non-supplement takers. Anemia and depleted iron stores were found only occasionally in all groups. In women, the prevalence of pre-latent iron deficiency and iron deficiency was highest in FXs (67%) compared to Vs (61%) and OMNs (54%). Conclusion: Our findings indicated that all three diets delivered sufficient amounts of most macro- and micronutrients. However, deficiencies in cobalamin, vitamin-D, and iron status were common across all diets. Further studies are needed to investigate the nutrient supply status and health consequences of meat-reduced plant-based diets. The study was registered in the German Clinical Trial Register (number: DRKS 00019887, data: 08.01.2020)

Effects of mineral waters on acid–base status in healthy adults

Background: The ‘Western diet’ typically consumed in industrialized countries is characterized by high amounts of processed cereal grains and animal products while being low in vegetables, tubers, and fruits. This dietary behavior leads to imbalances of acid–base status in favor of the acids and may cause low-grade metabolic acidosis (LGMA) that is associated with negative effects on health in the long run, including urolithiasis, bone loss, and even cardiometabolic diseases. Therefore, it has become of great interest to find dietary strategies that can be used to neutralize the acid load associated with Western diets. Objective: The aim of this study was to investigate whether the diet-dependent net acid load can be reduced by the daily consumption of mineral waters with different bicarbonate content and different potential renal acid load (PRAL). Methods: A single-centered, randomized trial including 129 healthy men and women aged from 18 to 75 years was conducted. Participants consumed 1,500–2,000 mL of one of four mineral waters with different bicarbonate content and different PRAL values daily for 4 weeks: low bicarbonate, high PRAL (LBHP, HCO3 −: 403.0 mg/L, PRAL: 10.7); medium-high bicarbonate, medium PRAL (MBMP, HCO3 − : 1816.0 mg/L, PRAL: −10.8); high bicarbonate, low PRAL (HBLP, HCO3 −: 2451.0 mg/L, PRAL: −19.3); medium-high bicarbonate, low PRAL (MBLP, HCO3 −: 1846.0 mg/L, PRAL: −22.1). Throughout the study, participants were asked to maintain their usual dietary habits. The primary outcome was the net acid excretion (NAE) measured in the 24-h urine output. Results: Consumption of the three mineral waters: MBMP, HBLP, and MBLP led to a significant decrease in NAE values. Within the MBMP group, the NAE could be reduced by 48% (P = 0.001), while consumption of HBLP led to a reduction of 68% (P < 0.001) and MBLP to a reduction of 53% (P = 0.001). Moreover, a slight increase in serum bicarbonate could also be observed in the groups that drank HBLP (P = 0.057) and MBLP (P = 0.001). Conclusion: Daily consumption of at least 1,500–2,000 mL of mineral water rich in bicarbonate (>1800.0 mg/L) with medium or low PRAL (<−11 mEq/L) can effectively reduce the NAE level by reducing the dietary acid load under free-living conditions in healthy adults

Exercise capacity of vegan, lacto-ovo-vegetarian and omnivorous recreational runners

Background In search of the right nutrition for the athlete, numerous nutritional strategies and diets were discussed over time. However, the influence of plant-based diets, especially veganism, on exercise capacity has not been clarified. Methods We conducted a cross-sectional study to compare the exercise capacity of vegan (VEG, n = 24), lacto-ovo-vegetarian (LOV, n = 26) and omnivorous (OMN, n = 26) recreational runners. To determine maximal exercise capacity, participants performed an incremental exercise test on a bicycle ergometer until voluntary exhaustion. During the test capillary blood samples were taken at several time points for the measurement of arterial lactate [lac] and glucose [glc] concentrations. To determine nutrient intake, a 24 h dietary recall was conducted. Results The groups showed comparable training habits in terms of training frequency (mean 3.08 ± 0.90 time/wk., p = 0.735), time (mean 2.93 ± 1.34 h/wk., p = 0.079) and running distance (mean 29.5 ± 14.3 km/wk., p = 0.054). Moreover, similar maximum power output (PmaxBW) was observed in all three groups (OMN: 4.15 ± 0.48 W/kg, LOV: 4.20 ± 0.47 W/kg, VEG: 4.16 ± 0.55 W/kg; p = 0.917) and no differences regarding [lac] throughout the exercise test and maximum lactate could be observed between the groups (OMN: 11.3 ± 2.19 mmol/l, LOV: 11.0 ± 2.59 mmol/l, VEG: 11.9 ± 1.98 mmol/l; p = 0.648). Conclusion The data indicate that each examined diet has neither advantages nor disadvantages with regard to exercise capacity. These results suggest that a vegan diet can be a suitable alternative for ambitious recreational runners

Assessment of the Mate Retention Inventory-Short Form Using Item Response Theory

The mate retention inventory (MRI) has been a valuable tool in the field of evolutionary psychology for the past 30 years. The goal of the current research is to subject the MRI to rigorous psychometric analysis using item response theory to answer three broad questions. Do the individual items of the MRI fit the scale well? Does the overall function of the MRI match what is predicted? Finally, do men and women respond similarly to the MRI? Using a graded response model, it was found that all but two of the items fit acceptable model patterns. Test information function analysis found that the scale acceptably captures individual differences for participants with a high degree of mate retention but the scale is lacking in capturing information from participants with a low degree of mate retention. Finally, discriminate item function analysis reveals that the MRI is better at assessing male than female participants, indicating that the scale may not be the best indicator of female behavior in a relationship. Overall, we conclude that the MRI is a good scale, especially for assessing male behavior, but it could be improved for assessing female behavior and individuals lower on overall mate retention behavior. It is suggested that this paper be used as a framework for how the newest psychometrics techniques can be applied in order to create more robust and valid measures in the field of evolutionary psychology

Quality of life among Syrian refugees in Germany: a cross-sectional pilot study

Background: More than 10 million Syrians have left their homes and sought refuge in neighboring countries, including Europe, since the beginning of the Syrian conflict in March 2011, and immigration continues to this day. This cross-sectional study included Syrian refugees residing in and around Hannover, Germany. We investigated whether general socioeconomic factors (e.g. age, sex, housing, asylum duration) were predictive factors for the quality of life (QOL) of Syrian refugees in Germany. Methods: The QOL of Syrian refugees was assessed using the WHOQOL-BREF tool, a questionnaire assessing the QOL in four domains: Physical health, psychological, social relationships and environment. A total of 114 Syrian refugees, aged between 18 and 45 years, who obtained one of the following statuses, asylum, refugee protection or subsidiary protection, were included. The QOL domain and total scores of Syrian refugees in Germany were compared with a Western norm and Sub-Saharan population. Data were analyzed with the Spearman Rho correlation coefficient, Kruskal–Wallis and Mann–Whitney U test and multivariate linear regression. Results: More than 65% of the participants (62.3% male, 37.7% female) were between 18 and 29 years old, and 45% had lived in Germany for less than four years. The lowest QOL score was reported in the social relationship’s domain (60.5%), while the psychological score was lowest in participants aged 40–45 years (P = 0.011). The age was significantly negatively associated with physical health (P = 0.010), psychological (P <  0.001) and the total QOL (P = 0.005). Asylum duration was associated with the environment domain (P = 0.040), the short-time refugees were less satisfied than the longtime refugees, and with aspects of the psychological domain in Enjoying life and Concentration ability (P <  0.001 and P = 0.033, respectively), yet was not associated with total QOL or total domain scores. There were significant associations between housing and the psychological domain (P = 0.032) and housing and the social relationship domain (P <  0.001). The refugees who living in camps registered a lower score in psychological than residents of apartments and houses, and the single refugees had a higher score than those married and divorced (P = 0.032 and P = 0.035, respectively). Conclusions: The Syrian refugees participating in this study showed a low QOL score in the assessment of all domains compared to the normal population, especially regarding social relations and psychological; it was associated with socioeconomic factors, such as housing, asylum duration and marital status. This calls for urgent societal and political efforts to strengthen the social living conditions of Syrian refugees in Germany

Intake of Calanus finmarchicus oil for 12 weeks improves omega-3 index in healthy older subjects engaging in an exercise programme

The n-3 PUFA, EPA and DHA, play an important role in human health. As the intake of EPA and DHA from the diet is often inadequate, supplementation of those fatty acids is recommended. A novel source of n-3 PUFA is Calanus finmarchicus oil (CO) which contains fatty acids mainly bound in wax esters. To date, no data are available on the effects of long-term intake of this marine oil on n-3 PUFA blood levels. Therefore, the aim of this study was to evaluate the effect of CO on the n-3 PUFA blood levels using the omega-3 index (O3I). The data originate from a larger randomised controlled trial. For this analysis, samples from seventy-two participants (59·2 (sd 6·2) years, BMI 27·7 (sd 5·28) kg/m2) were analysed. Of those, thirty-six performed 2×/week exercise and received 2 g of CO, which provided 124 mg stearidonic acid (SDA), 109 mg EPA and 87 mg DHA daily (EXCO group), while the other group performed exercise only (EX group) and served as a control for this analysis. The O3I increased from 6·07 (sd 1·29) % at baseline to 7·37 (sd 1·10) % after 12 weeks within the EXCO group (P < 0·001), while there were no significant changes in the EX group (6·01 (sd 1·26)–6·15 (sd 1·32) %, P = 0·238). These data provide first evidence that wax ester-bound n-3 PUFA from CO can significantly increase the O3I despite relatively low EPA + DHA amounts. Further, the effects of exercise could be excluded