Biomarker signatures associated with ageing free of major chronic diseases: results from a population-based sample of the EPIC-Potsdam cohort.

BACKGROUND: A number of biomarkers denoting various pathophysiological pathways have been implicated in the aetiology and risk of age-related diseases. Hence, the combined impact of multiple biomarkers in relation to ageing free of major chronic diseases, such as cancer, cardiovascular disease and type 2 diabetes, has not been sufficiently explored. METHODS: We measured concentrations of 13 biomarkers in a random subcohort of 2,500 participants in the European Prospective Investigation into Cancer and Nutrition Potsdam study. Chronic disease-free ageing was defined as reaching the age of 70 years within study follow-up without major chronic diseases, including cardiovascular disease, type 2 diabetes or cancer. Using a novel machine-learning technique, we aimed to identify biomarker clusters and explore their association with chronic disease-free ageing in multivariable-adjusted logistic regression analysis taking socio-demographic, lifestyle and anthropometric factors into account. RESULTS: Of the participants who reached the age of 70 years, 321 met our criteria for chronic-disease free ageing. Machine learning analysis identified three distinct biomarker clusters, among which a signature characterised by high concentrations of high-density lipoprotein cholesterol, adiponectin and insulin-like growth factor-binding protein 2 and low concentrations of triglycerides was associated with highest odds for ageing free of major chronic diseases. After multivariable adjustment, the association was attenuated by socio-demographic, lifestyle and adiposity indicators, pointing to the relative importance of these factors as determinants of healthy ageing. CONCLUSION: These data underline the importance of exploring combinations of biomarkers rather than single molecules in understanding complex biological pathways underpinning healthy ageing.

Risks of misinterpretation of biomarker measurements in spot urine adjusted for creatinine - A problem especially for studies comparing plant based with omnivorous diets.

Biomarker measurements in spot urine are often adjusted for creatinine to control for dilution resulting from individual hydration. We here report on results of a study involving age- and sex-matched vegans and omnivores (n = 36 each). The daily urinary excretion of 2,3-dihydroxypropylmercapturic acid (DHPMA, a diet-independent endogenous C3-metabolite used as an example compound) was found not to be different in vegans and omnivores (median 433 µg/24 h each), however, creatinine-adjusted levels were 26% lower in omnivores (median 285 µg/g creatinine) than in vegans (median 383 µg/g creatinine, p = 0.003). This difference results from the higher urinary excretion of creatinine in the omnivores compared to vegans (median 1.51 vs. 1.21 g/24 h, p = 0.009). Linear regression showed - besides the fat-free mass - a significant impact of the factor diet (vegans vs. omnivores). This may be due to the consumption of meat and fish as exogenous sources of creatinine. A literature search revealed broad evidence for this interpretation, as creatinine is formed from creatine during heating of meat and fish. Accordingly, consumption leads to temporary increase of serum/plasma creatinine and urinary creatinine excretion, resulting in higher levels in omnivores compared to vegans/vegetarians. An adjustment of the urinary DHPMA concentrations using specific gravity revealed 13% lower values in omnivores (median 225 µg/L) than in vegans (median 260 µg/L, p = 0.07). Compared to creatinine-adjustment, adjustment for specific gravity introduces a smaller but still obvious difference between omnivores and vegans. Especially with respect to future studies comparing vegans, vegetarians and omnivores, researchers should be aware of the risks of severe misinterpretations if biomarker measurements in spot urine are adjusted for creatinine.

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.

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.

Knowledge and awareness about and use of iodised salt among students in Germany and Greece.

BACKGROUND: Iodine is an essential trace element, which is important for human metabolism, growth and mental development. Iodine deficiency may still occur in Europe and the use of iodised salt is an effective measure to enhance iodine intake. Knowledge and awareness about the importance of iodine in nutrition and health can have a positive impact on the use of iodised salt. Therefore, the aim of this study was to assess the knowledge about and use of iodised salt among university students in two European countries. METHOD: Data from two countries (Germany and Greece) were extracted from a multi-centre cross-sectional survey, conducted among non-nutrition science/non-medical students from October 2018 to April 2019. RESULTS: Among the 359 participants in Germany (35% females, median age: 22 years) and the 403 participants in Greece (51% females, median age: 21 years), 41% and 37%, respectively, reported use of iodised salt at home. Users and non-users did not differ by age, gender and Body Mass Index or general interest in nutrition in both cohorts. However, those who had a better knowledge about iodine and (iodised) salt or had previously attended nutrition classes were more likely to report iodised salt usage. CONCLUSION: The results suggest that strengthening the imparting of nutritional information and additional education of young adults are needed and may improve knowledge about and usage of iodised salt.

Retinol and Retinol Binding Protein 4 Levels and Cardiometabolic Disease Risk.

BACKGROUND: Despite mechanistic studies linking retinol and RBP4 (retinol binding protein 4) to the pathogenesis of cardiovascular diseases (CVD) and type 2 diabetes (T2D), epidemiological evidence is still conflicting. We investigated whether conflicting results of previous studies may be explained by differences in the association of retinol and RBP4 with cardiometabolic risk across subgroups with distinct sex, hypertension state, liver, or kidney function. METHODS: We used case-cohorts nested in the EPIC (European Prospective Investigation Into Cancer and Nutrition)-Potsdam cohort (N=27 548) comprising a random sample of participants (n=2500) and all physician-verified cases of incident CVD (n=508, median follow-up time 8.2 years) and T2D (n=820, median follow-up time 6.3 years). We estimated nonlinear and linear multivariable-adjusted associations between the biomarkers and cardiometabolic diseases by restricted cubic splines and Cox regression, respectively, testing potential interactions with hypertension, liver, and kidney function. Additionally, we performed 2-sample Mendelian Randomization analyses in publicly available data. RESULTS: The association of retinol with cardiometabolic risk was modified by hypertension state (P interaction CVD<0.001; P interaction T2D<0.001). Retinol was associated with lower cardiometabolic risk in participants with treated hypertension (hazard ratioper SD [95% CI]: CVD, 0.71 [0.56-0.90]; T2D, 0.81 [0.70-0.94]) but with higher cardiometabolic risk in normotensive participants (CVD, 1.32 [1.06-1.64]; T2D, 1.15 [0.98-1.36]). Our analyses also indicated a significant interaction between RBP4 and hypertension on CVD risk (P interaction=0.04). Regarding T2D risk, we observed a u-shaped association with RBP4 in women (P nonlinearity=0.01, P effect=0.02) and no statistically significant association in men. The biomarkers' interactions with liver or kidney function were not statistically significant. Hypertension state-specific associations for retinol concentrations with cardiovascular mortality risk were replicated in National Health and Nutrition Examination Survey III. CONCLUSIONS: Our findings suggest a hypertension-dependent relationship between plasma retinol and cardiometabolic risk and complex interactions of RBP4 with sex and hypertension on cardiometabolic risk.

Dietary and Plasma Phospholipid Profiles in Vegans and Omnivores-Results from the RBVD Study.

Over the last few years, the vegan diet has become increasingly popular in Germany. It has been proposed that this diet is generally lower in fat, but less is known about the impact on fatty acid (FA) profiles. Therefore, the cross-sectional "Risks and Benefits of a Vegan Diet" (RBVD) study (n = 72) was used to investigate dietary FA intake as well as plasma phospholipid FA in vegans (n = 36) compared to omnivores (n = 36). Vegans had a significantly lower dietary intake of total fat (median 86 g/day, IQR 64−111) in comparison to omnivores (median 104 g/day, IQR 88−143, p = 0.004). Further, vegans had a lower intake of saturated fatty acids (SFA) (p < 0.0001) and monounsaturated fatty acids (MUFA) (p = 0.001) compared to omnivores. Vegans had a higher intake in total polyunsaturated fatty acids (PUFA), omega-3 and omega-6 PUFA compared to omnivores, but without statistical significance after Bonferroni correction. According to plasma phospholipid profiles, relatively lower proportions of SFA (p < 0.0001), total trans fatty acids (TFA) (p = 0.0004) and omega-3-FA (p < 0.0001), but higher proportions of omega-6-FA (p < 0.0001) were observed in vegans. With the exception of omega-3 PUFA, a vegan diet is associated with a more favorable dietary fat intake and more favorable plasma FA profiles and therefore may reduce cardiovascular risk.

Comparison of Five Oxidative Stress Biomarkers in Vegans and Omnivores from Germany and Finland.

When the amount of reactive oxygen species produced by human metabolism cannot be balanced by antioxidants, this phenomenon is commonly referred to as oxidative stress. It is hypothesised that diets with high amounts of plant food products may have a beneficial impact on oxidative stress status. However, few studies have examined whether a vegan diet is associated with lower oxidative stress compared to an omnivorous diet. The present cross-sectional study aimed to compare the levels of five oxidative stress biomarkers in vegans and omnivores. Data of 36 vegans and 36 omnivores from Germany and of 21 vegans and 18 omnivores from Finland were analysed. HPLC coupled with mass spectrometry or fluorescence detection and ELISA methods were used to measure the oxidative stress biomarkers malondialdehyde (MDA), protein carbonyls and 3-nitrotyrosine in plasma and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin F2α (8-iso-PGF2α) in 24 h urine. Analyses of variance and covariance, considering potential confounders, were used. Vegans and omnivores showed no differences in MDA and protein carbonyl concentrations. In Finnish but not in German vegans, the concentrations of 3-nitrotyrosine were lower compared to those in omnivores (p = 0.047). In Germany, vegans showed lower excretion levels of 8-iso-PGF2α than omnivores (p = 0.002) and with a trend also of 8-OHdG (p = 0.05). The sensitivity analysis suggests lower 8-iso-PGF2α excretion levels in women compared to men, independently of the dietary group. The present study contributes to expanding our knowledge of the relationship between diet and oxidative stress and showed that 3-nitrotyrosine, 8-OHdG and 8-iso-PGF2α tended to be lower in vegans. Furthermore, studies are recommended to validate the present findings.

Nutritional Intake and Biomarker Status in Strict Raw Food Eaters.

Following a strict raw food diet (primarily based on fresh fruit and raw vegetables, waiving any consumption of heated or processed food) has the risk of undersupply of energy and certain macro- and micronutrients. In this cross-sectional study, we compared 16 non-smoking strict raw food eaters (5 women and 11 men, age 44.6 ± 12.3 years, duration of following the diet 11.6 ± 10.8 years) with the non-smoking participants (32 vegans, 27 omnivores) of the "Risk and Benefits of a Vegan Diet" (RBVD) study. We investigated body composition, dietary intake from 3-day weighed food records, and relevant fasting blood and serum parameters. Food choice and dietary behavior were very heterogenic in raw food eaters. They had lower mean values of BMI and percentage of body fat than the respective RBVD participants. The same holds true for energy supply and intakes of protein, carbohydrate, calcium and iodine. Serum levels revealed lower levels of HDL cholesterol, triglycerides, zinc, and vitamin D3. The raw food eaters with (n = 9) and without (n = 7) supplementation of vitamin B12 had median vitamin B12 levels of 399 and 152 ng/L, respectively. Accordingly, eight raw food eaters (50%) had homocysteine levels above 12 µmol/L. The study allows a close look at strict raw food eaters with respect to possible dietary deficiencies, but also provides insights into motivations and daily life.

A Critical Scoping Review of Pesticide Exposure Biomonitoring Studies in Overhead Cultures.

The exposure of operators, workers, residents and bystanders to pesticides is of high potential concern. Yet, reports on pesticide residues in the environment and near treated fields often spark debates if such findings might indicate a health risk. Although the underlying models are considered conservative, there are only limited field data on systemic exposure available. As a first step to improve the situation, we conducted a scoping review of state-of-the-art pesticide exposure biomonitoring studies in operators, workers, residents or bystanders. In contrast to existing reviews, we focused on target cultures of potential high pesticide exposure such as tree-grown produce, vine or hops. The search was conducted in Web of Science, Scopus and PubMed. Out of 17 eligible articles, a total of 11 studies met our search criteria, and 6 of them quantified the systemic exposure of humans. The analysis revealed that exposure was mainly driven by application of pesticides and reentry work, resulting in a higher exposure of operators and workers than of residents and bystanders. In nearly all cases, the systemic exposure was below the relevant toxicological reference values. The studies were subsequently analyzed to identify key criteria for a reliable design of a biomonitoring study on pesticide exposure.

Plasma Industrial and Ruminant Trans Fatty Acids and Incident Type 2 Diabetes in the EPIC-Potsdam Cohort.

OBJECTIVE: Although dietary intake of trans fatty acid (TFA) is a major public health concern because of the associated increase in the risk of cardiovascular events, it remains unclear whether TFAs also influence risk of type 2 diabetes (T2D) and whether industrial TFAs (iTFAs) and ruminant TFAs (rTFAs) exert the same effect on health. RESEARCH DESIGN AND METHODS: To investigate the relationship of 7 rTFAs and iTFAs, including 2 conjugated linoleic acids (CLAs), plasma phospholipid TFAs were measured in a case-cohort study nested within the European Prospective Investigation Into Cancer and Nutrition-Potsdam cohort. The analytical sample was a random subsample (n = 1,248) and incident cases of T2D (n = 801) over a median follow-up of 6.5 years. Using multivariable Cox regression models, we examined associations of TFAs with incident T2D. RESULTS: The TFA subtypes were intercorrelated with each other, with other fatty acids, and with different food sources. After controlling for other TFAs, the iTFAs (18:1n-6t, 18:1n-9t, 18:2n-6,9t) were not associated with diabetes risk. Some rTFA subtypes were inversely associated with diabetes risk: vaccenic acid (18:1n-7t; hazard ratio [HR] per SD 0.72; 95% CI 0.58-0.89) and t10c12-CLA (HR per SD 0.81; 95% CI 0.70-0.94), whereas c9t11-CLA was positively associated (HR per SD 1.39; 95% CI 1.19-1.62). Trans-palmitoleic acid (16:1n-7t) was not associated with diabetes risk when adjusting for the other TFAs (HR per SD 1.08; 95% CI 0.88-1.31). CONCLUSIONS: The TFAs' conformation plays an essential role in their relationship to diabetes risk. rTFA subtypes may have opposing relationships to diabetes risk. Previous observations for reduced diabetes risk with higher levels of circulating trans-palmitoleic acid are likely due to confounding.

Mycotoxins in Serum and 24-h Urine of Vegans and Omnivores from the Risks and Benefits of a Vegan Diet (RBVD) Study.

SCOPE: Vegans might have a higher exposure to mycotoxins due to their heightened consumption of typical mycotoxin containing food sources. Yet, data on internal exposure among vegans in comparison to omnivores are currently lacking. METHODS AND RESULTS: This cross-sectional study includes 36 vegans and 36 omnivores (50% females, 30-60 years). A set of 28 and 27 mycotoxins is analyzed in 24-h urine and serum samples, respectively, by validated multi-mycotoxin methods (HPLC-MS/MS). Ochratoxin A (OTA), 2'R-OTA, and enniatin B in serum as well as deoxynivalenol-glucuronide in 24-h urine are quantified in 57-100% of the samples. Serum OTA levels are twofold higher in vegans than in omnivores (median 0.24 ng mL-1 vs 0.12 ng mL-1 ; p < 0.0001). No further significant differences were observed. Serum OTA levels are associated with intake of "vegan products" (r = 0.50, p < 0.0001) and "pasta & rice" (r = 0.33, p = 0.006). Sensitivity analyses advise cautious interpretation. Furthermore, serum levels of 2'R-OTA are related to coffee consumption (r = 0.64, p < 0.0001). CONCLUSION: The results indicate a higher exposure of vegans to OTA, but not to other mycotoxins. However, larger studies with repeated measurements are required to better evaluate the exposure to mycotoxins from plant-based diets.

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.

A newly developed and externally validated non-clinical score accurately predicts 10-year cardiovascular disease risk in the general adult population.

Inclusion of clinical parameters limits the application of most cardiovascular disease (CVD) prediction models to clinical settings. We developed and externally validated a non-clinical CVD risk score with a clinical extension and compared the performance to established CVD risk scores. We derived the scores predicting CVD (non-fatal and fatal myocardial infarction and stroke) in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort (n = 25,992, cases = 683) using competing risk models and externally validated in EPIC-Heidelberg (n = 23,529, cases = 692). Performance was assessed by C-indices, calibration plots, and expected-to-observed ratios and compared to a non-clinical model, the Pooled Cohort Equation, Framingham CVD Risk Scores (FRS), PROCAM scores, and the Systematic Coronary Risk Evaluation (SCORE). Our non-clinical score included age, gender, waist circumference, smoking, hypertension, type 2 diabetes, CVD family history, and dietary parameters. C-indices consistently indicated good discrimination (EPIC-Potsdam 0.786, EPIC-Heidelberg 0.762) comparable to established clinical scores (thereof highest, FRS: EPIC-Potsdam 0.781, EPIC-Heidelberg 0.764). Additional clinical parameters slightly improved discrimination (EPIC-Potsdam 0.796, EPIC-Heidelberg 0.769). Calibration plots indicated very good calibration with minor overestimation in the highest decile of predicted risk. The developed non-clinical 10-year CVD risk score shows comparable discrimination to established clinical scores, allowing assessment of individual CVD risk in physician-independent settings.

Detection of a Hemoglobin Adduct of the Food Contaminant Furfuryl Alcohol in Humans: Levels of N-((Furan-2-yl)methyl)-valine in Two Epidemiological Studies.

SCOPE: Furfuryl alcohol is a heat-induced food contaminant, classified as possibly carcinogenic to humans. The proximal carcinogen 2-sulfoxymethylfuran leads to adduct formation in DNA and proteins (e.g., N-((furan-2-yl)methyl)-Val (FFA-Val) in hemoglobin). METHODS AND RESULTS: This study analyzed human erythrocyte samples from two studies for the presence of FFA-Val: the Risks and Benefits of a Vegan Diet study (RBVD; 72 adults) and the ENVIRonmental influence ON early AGEing birth cohort study (ENVIRONAGE; 100 mother-newborn pairs). In the RBVD study, FFA-Val levels are lower in vegans compared to omnivores (median 13.0 vs 15.8 pmol g-1 hemoglobin, p = 0.008), and lower in non-smokers compared to smokers (median 14.1 vs 17.0 pmol g-1 hemoglobin, p = 0.003). In the birth cohort, FFA-Val levels are distinctly higher in maternal compared to newborn samples (median 15.2 vs 2.2 pmol g-1 hemoglobin, p < 0.001). CONCLUSIONS: FFA-Val, hitherto detected only in blood samples of mice, is quantifiable in all human samples, indicating a general exposure to furfuryl alcohol. The low adduct levels in blood samples from newborn children suggested that the placenta is a barrier to furfuryl alcohol. Dietary habits and tobacco smoking are two main influencing factors on the formation of FFA-Val, which may be of use as a biomarker of exposure to furfuryl alcohol.

Determinants of elevated chemerin as a novel biomarker of immunometabolism: data from a large population-based cohort.

OBJECTIVE: Chemerin is a novel inflammatory biomarker suggested to play a role in the development of metabolic disorders, providing new avenues for treatment and prevention. Little is known about the factors that predispose elevated chemerin concentrations. We therefore aimed to explore a range of lifestyle-associated, dietary, and metabolic factors as potential determinants of elevated chemerin concentrations in asymptomatic adults. DESIGN: We used cross-sectional data from a random subsample of 2433 participants (1494 women and 939 men) aged 42-58 years of the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort. METHODS: Random forest regression (RFR) was applied to explore the relative importance of 32 variables as statistical predictors of elevated chemerin concentrations overall and by sex. Multivariable-adjusted linear regression was applied to evaluate associations between selected predictors and chemerin concentrations. RESULTS: Results from RFR suggested BMI, waist circumference, C-reactive protein, fatty liver index, and estimated glomerular filtration rate as the strongest predictors of chemerin concentrations. Additional predictors included sleeping duration, alcohol, red and processed meat, fruits, sugar-sweetened beverages (SSB), vegetables, dairy, and refined grains. Collectively, these factors explained 32.9% variation of circulating chemerin. Multivariable-adjusted analyses revealed linear associations of elevated chemerin with metabolic parameters, obesity, longer sleep, higher intakes of red meat and SSB, and lower intakes of dairy. CONCLUSIONS: These findings come in support of the role of chemerin as a biomarker characterizing inflammatory and metabolic phenotypes in asymptomatic adults. Modifiable dietary and lifestyle-associated determinants of elevated chemerin concentrations require further evaluation in a prospective study setting.

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.

Short- and Branched-Chain Fatty Acids as Fecal Markers for Microbiota Activity in Vegans and Omnivores.

A vegan diet could impact microbiota composition and bacterial metabolites like short-chain (SCFA) and branched-chain fatty acids (BCFA). The aim of this study was to compare the concentrations of SCFA, BCFA, ammonia, and fecal pH between vegans and omnivores. In this cross-sectional study (vegans n = 36; omnivores n = 36), microbiota composition, fecal SCFA, BCFA, and ammonia concentrations and pH were analyzed in complete stool samples. A random forest regression (RFR) was used to identify bacteria predicting SCFA/BCFA concentrations in vegans and omnivores. No significant differences in SCFA and BCFA concentrations were observed between vegans and omnivores. Fecal pH (p = 0.005) and ammonia concentration (p = 0.01) were significantly lower in vegans than in omnivores, while fiber intake was higher (p < 0.0001). Shannon diversity was higher in omnivores compared to vegans on species level (p = 0.04) only. In vegans, a cluster of Faecalibacterium prausnitzii, Prevotella copri, Dialister spp., and Eubacterium spp. was predictive for SCFA and BCFA concentrations. In omnivores, Bacteroides spp., Clostridium spp., Ruminococcus spp., and Prevotella copri were predictive. Though SCFA and BCFA did not differ between vegans and omnivores, the results of the RFR suggest that bacterial functionality may be adapted to varying nutrient availability in these diets.

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

Scientific evidence suggests that a vegan diet might be associated with impaired bone health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the investigation of differences in the concentrations of nutrition- and bone-related biomarkers between vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores: 118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate, and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression, 12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids, urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may contribute to bone health. Further studies are needed to confirm these findings.

BMI and BMI change following incident type 2 diabetes and risk of microvascular and macrovascular complications: the EPIC-Potsdam study.

AIMS/HYPOTHESIS: Studies suggest decreased mortality risk among people who are overweight or obese compared with individuals with normal weight in type 2 diabetes (obesity paradox). However, the relationship between body weight or weight change and microvascular vs macrovascular complications of type 2 diabetes remains unresolved. We investigated the association between BMI and BMI change with long-term risk of microvascular and macrovascular complications in type 2 diabetes in a prospective cohort study. METHODS: We studied participants with incident type 2 diabetes from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort, who were free of cancer, cardiovascular disease and microvascular disease at diagnosis (n = 1083). Pre-diagnosis BMI and relative annual change between pre- and post-diagnosis BMI were evaluated in multivariable-adjusted Cox models. RESULTS: There were 85 macrovascular (myocardial infarction and stroke) and 347 microvascular events (kidney disease, neuropathy and retinopathy) over a median follow-up of 10.8 years. Median pre-diagnosis BMI was 29.9 kg/m2 (IQR 27.4-33.2), and the median relative annual BMI change was -0.4% (IQR -2.1 to 0.9). Higher pre-diagnosis BMI was positively associated with total microvascular complications (multivariable-adjusted HR per 5 kg/m2 [95% CI]: 1.21 [1.07, 1.36], kidney disease 1.39 [1.21, 1.60] and neuropathy 1.12 [0.96, 1.31]) but not with macrovascular complications (HR 1.05 [95% CI 0.81, 1.36]). Analyses according to BMI categories corroborated these findings. Effect modification was not evident by sex, smoking status or age groups. In analyses according to BMI change categories, BMI loss of more than 1% indicated a decreased risk of total microvascular complications (HR 0.62 [95% CI 0.47, 0.80]), kidney disease (HR 0.57 [95% CI 0.40, 0.81]) and neuropathy (HR 0.73 [95% CI 0.52, 1.03]), compared with participants with a stable BMI; no clear association was observed for macrovascular complications (HR 1.04 [95% CI 0.62, 1.74]). The associations between BMI gain compared with stable BMI and diabetes-related vascular complications were less apparent. Associations were consistent across strata of sex, age, pre-diagnosis BMI or medication but appeared to be stronger among never-smokers compared with current or former smokers. CONCLUSIONS/INTERPRETATION: Among people with incident type 2 diabetes, pre-diagnosis BMI was positively associated with microvascular complications, while a reduced risk was observed with weight loss when compared with stable weight. The relationships with macrovascular disease were less clear.