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 However, previous studies investigating the relationship between vegetarian diets and sports are outdated, questionnaire-based and did not include nutritional or sports medical diagnostics, had a very low sample size or included only vegetarians and omnivores.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

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

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

Characterization, dietary habits and nutritional intake of omnivorous, lacto-ovo vegetarian and vegan runners – a pilot study

Background The number of people preferring plant-based nutrition is growing continuously in the western world. Vegetarianism and veganism are also becoming increasingly popular among individuals participating in sport. However, whether recreationally active vegetarian and vegan populations can meet their nutritional needs is not clear. Methods The purpose of this cross-sectional study was to compare the nutrient intake of omnivorous (OMN, n = 27), lacto-ovo vegetarian (LOV, n = 25) and vegan (VEG, n = 27) recreational runners (two to five training sessions per week) with intake recommendations of the German, Austrian and Swiss Nutrition Societies (Deutsche, Österreichische und Schweizerische Gesellschaften für Ernährung, D-A-CH) for the general population. Lifestyle factors and supplement intake were examined via questionnaires; dietary habits and nutrient intake were determined based on 3-day dietary records. Results More than half of each group did not reach the recommended energy intake (OMN: 10.4, 8.70–12.1; LOV: 9.67, 8.55–10.8; VEG: 10.2, 9.12–11.3 MJ). Carbohydrate intake was slightly below the recommendations of > 50 EN% in OMN (46.7, 43.6–49.8 EN%), while LOV (49.4, 45.5–53.3 EN%) and VEG (55.2, 51.4–59.0 EN%) consumed adequate amounts (p = 0.003). The recommended protein intake of 0.8 g/kg body weight (D-A-CH) was exceeded in all three groups (OMN: 1.50, 1.27–1.66; LOV: 1.34, 1.09–1.56; VEG: 1.25; 1.07–1.42 g/kg BW; p = 0.047). Only VEG (26.3, 22.7–29.8 EN%) did not achieve the recommended fat intake of 30 EN%. The supply of micronutrients, such as vitamin D and cobalamin, was dependent on supplement intake. Additionally, female OMN and LOV achieved the recommended daily intake of 15 mg iron only after supplementation, while VEG consumed adequate amounts solely via food. Conclusion All three groups were sufficiently supplied with most nutrients despite the exceptions mentioned above. The VEG group even showed advantages in nutrient intake (e.g. carbohydrates, fiber and iron) in comparison to the other groups. However, the demand for energy and several macro- and micronutrients might be higher for athletes. Thus, it is also necessary to analyze the endogenous status of nutrients to evaluate the influence of a vegetarian and vegan diet on the nutrient supply of athletes

Exercise-induced oxidative stress, nitric oxide and plasma amino acid profile in recreational runners with vegetarian and non-vegetarian dietary patterns

This study investigated the exercise-induced changes in oxidative stress, nitric oxide (NO) metabolism and amino acid profile in plasma of omnivorous (OMN, n = 25), lacto-ovo-vegetarian (LOV, n = 25) and vegan (VEG, n = 23) recreational runners. Oxidative stress was measured as malondialdehyde (MDA), NO as nitrite and nitrate, and various amino acids, including homoarginine and guanidinoacetate, the precursor of creatine. All analytes were measured by validated stable-isotope dilution gas chromatographic-mass spectrometric methods. Pre-exercise, VEG had the highest MDA and nitrate concentrations, whereas nitrite concentration was highest in LOV. Amino acid profiles differed between the groups, with guanidinoacetate being highest in OMN. Upon acute exercise, MDA increased in the LOV and VEG group, whereas nitrate, nitrite and creatinine did not change. Amino acid profiles changed post-exercise in all groups, with the greatest changes being observed for alanine (+28% in OMN, +21% in LOV and +28% in VEG). Pre-exercise, OMN, LOV and VEG recreational runners differ with respect to oxidative stress, NO metabolism and amino acid profiles, in part due to their different dietary pattern. Exercise elicited different changes in oxidative stress with no changes in NO metabolism and closely comparable elevations in alanine. Guanidinoacetate seems to be differently utilized in OMN, LOV and VEG, pre- and post-exercise

Effects of Exercise Combined with a Healthy Diet or Calanus finmarchicus Oil Supplementation on Body Composition and Metabolic Markers : A Pilot Study

Aging is accompanied by a progressive decline in muscle mass and an increase in fat mass, which are detrimental changes associated with the development of health conditions such as type-2 diabetes mellitus or chronic low-grade inflammation. Although both exercise as well as nutritional interventions are known to be beneficial in counteracting those age-related changes, data to which extent untrained elderly people may benefit is still sparse. Therefore, a randomized, controlled, 12-week interventional trial was conducted in which 134 healthy untrained participants (96 women and 38 men, age 59.4 ± 5.6 years, body mass index (BMI) 28.4 ± 5.8 kg/m2) were allocated to one of four study groups: (1) control group with no intervention (CON); (2) 2×/week aerobic and resistance training only (EX); (3) exercise routine combined with dietary counseling in accordance with the guidelines of the German Nutrition Society (EXDC); (4) exercise routine combined with intake of 2 g/day oil from Calanus finmarchicus (EXCO). Body composition (bioelectrical impedance analysis), as well as markers of glucose metabolism and blood lipids, were analyzed at the beginning and the end of the study. The highest decreases in body fat were observed within the EXCO group (−1.70 ± 2.45 kg, p < 0.001), and the EXDC (−1.41 ± 2.13 kg, p = 0.008) group. Markers of glucose metabolism and blood lipids remained unchanged in all groups. Taken together results of this pilot study suggest that a combination of moderate exercise and intake of oil from Calanus finmarchicus or a healthy diet may promote fat loss in elderly untrained overweight participants

Impact of Dietary Modifications on Plasma Sirtuins 1, 3 and 5 in Older Overweight Individuals Undergoing 12-Weeks of Circuit Training

Sirtuins are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases that regulate numerous pathways such as mitochondrial energy metabolism in the human body. Lower levels of these enzymes were linked to diseases such as diabetes mellitus and were also described as a result of aging. Sirtuins were previously shown to be under the control of exercise and diet, which are modifiable lifestyle factors. In this study, we analyzed SIRT1, SIRT3 and SIRT5 in blood from a subset of healthy elderly participants who took part in a 12-week randomized, controlled trial during which they performed, twice-weekly, resistance and aerobic training only (EX), the exercise routine combined with dietary counseling in accordance with the guidelines of the German Nutrition Society (EXDC), the exercise routine combined with intake of 2 g/day oil from Calanus finmarchicus (EXCO), or received no treatment and served as the control group (CON). In all study groups performing exercise, a significant increase in activities of SIRT1 (EX: +0.15 U/mg (+0.56/−[−0.16]), EXDC: +0.25 U/mg (+0.52/−0.06), EXCO: +0.40 U/mg (+0.88/−[−0.12])) and SIRT3 (EX: +0.80 U/mg (+3.18/−0.05), EXDC: 0.95 U/mg (+3.88/−0.55), EXCO: 1.60 U/mg (+2.85/−0.70)) was detected. Group comparisons revealed that differences in SIRT1 activity in EXCO and EXDC differed significantly from CON (CON vs. EXCO, p = 0.003; CON vs. EXDC, p = 0.010). For SIRT3, increases in all three intervention groups were significantly different from CON (CON vs. EX, p = 0.007; CON vs. EXDC, p < 0.001, CON vs. EXCO, p = 0.004). In contrast, differences in SIRT5-activities were less pronounced. Altogether, the analyses showed that the activity of SIRT1 and SIRT3 increased in response to the exercise intervention and that this increase may potentially be enhanced by additional dietary modifications

12-week combined strength and endurance exercise attenuates CD8+ T-cell differentiation and affects the kynurenine pathway in the elderly: a randomized controlled trial

Background: Age-related accumulation of highly differentiated CD8+ effector memory re-expressing CD45RA (EMRA) T-cells and disruption of the kynurenine (KYN) pathway are associated with chronic inflammation and the development of insulin resistance. In this study the aim was to investigate the effects of 12-week combined strength and endurance exercise on CD8+ T-cell differentiation and KYN pathway metabolites. Ninety-six elderly subjects (f/m, aged 50—70) were randomized to a control (CON) or exercise (EX) group. The EX group completed combined strength and endurance training twice weekly for one hour each time at an intensity of 60% of the one-repetition maximum for strength exercises and a perceived exertion of 15/20 for endurance exercises. The EX group was also randomly subdivided into two groups with or without a concomitant balanced diet intervention in order to examine additional effects besides exercise alone. Before and after the intervention phase, the proportions of CD8+ T-cell subsets and levels of KYN pathway metabolites in peripheral blood were determined. Results: The CD8+ EMRA T-cell subsets increased in the CON group but remained almost unchanged in the EX group (p =.02). Plasma levels of kynurenic acid (KA) increased in the EX group and decreased in the CON group (p =.03). Concomitant nutritional intervention resulted in lower levels of quinolinic acid (QA) compared with exercise alone (p =.03). Overall, there was a slight increase in the QA/KA ratio in the CON group, whereas it decreased in the EX group (p >.05). Conclusions: Combined strength and endurance training seems to be a suitable approach to attenuate CD8+ T-cell differentiation in the elderly and to redirect the KYN pathway towards KA. The clinical relevance of these effects needs further investigation