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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.

Background: Consumption of foods of insect origin is encouraged, since insect consumption is seen as one of the responses to the environmental impact of meat production. This study examines the attitude (A), subjective norm (SN), perceived behavioral control (PC), and food neophobia (FN) toward the consumption of foods of insect origin, as well as the conditions for eating insect-based foods among vegans, vegetarians, and omnivores., Methods: The data was obtained by using an online survey and convenience sampling ( n = 567, of whom omnivores represented 74%, vegans 5%, and non-vegan vegetarians 22%)., Results: The three dietary groups exhibited significantly different intention (I) to eat foods of insect origin. Vegans held the most rigid negative attitude (A), and their subjective norm (SN) to eat insects was weaker compared to that of omnivores ( p < 0.001) and non-vegan vegetarians ( p < 0.001). Vegans' perceived behavioral control (PC) over their eating of insects was stronger compared to that of omnivores ( p < 0.001) and non-vegan vegetarians p < 0.001), and they were more neophobic than omnivores ( p < 0.001) and non-vegan vegetarians ( p < 0.001). Non-vegan vegetarians held the most positive attitude toward eating insects, and both non-vegan vegetarians and omnivores thought that insect consumption is wise and offers a solution to the world's nutrition problems. In contrast, vegans regarded insect consumption as immoral and irresponsible., Conclusions: Vegans' weak intention, negative attitude, and low willingness to eat insects in the future exhibit their different dietarian identity compared to that of omnivores and non-vegan vegetarians.

Background: Vegetarian and vegan diets have become more popular among adolescents and young adults. However, few studies have investigated the nutritional status of vegans, who may be at risk of nutritional deficiencies., Objective: To compare dietary intake and nutritional status of Finnish long-term vegans and non-vegetarians., Methods: Dietary intake and supplement use were estimated using three-day dietary records. Nutritional status was assessed by measuring biomarkers in plasma, serum, and urine samples. Vegans' (n = 22) data was compared with those of sex- and age-matched non-vegetarians (n = 19)., Results: All vegans adhered strictly to their diet; however, individual variability was marked in food consumption and supplementation habits. Dietary intakes of key nutrients, vitamins B12 and D, were lower (P < 0.001) in vegans than in non-vegetarians. Nutritional biomarker measurements showed lower concentrations of serum 25-hydroxyvitamin D3 (25(OH)D3), iodine and selenium (corrected for multiple comparisons, P < 0.001), Vegans showed more favorable fatty acid profiles (P < 0.001) as well as much higher concentrations of polyphenols such as genistein and daidzein (P < 0.001). Eicosapentaenoic acid proportions in vegans were higher than expected. The median concentration of iodine in urine was below the recommended levels in both groups., Conclusions: Long-term consumption of a vegan diet was associated with some favorable laboratory measures but also with lowered concentrations of key nutrients compared to reference values. This study highlights the need for nutritional guidance to vegans.