# The Role of Fermented Vegetables as a Sustainable and Health-Promoting Nutritional Resource
## 2 Determinants for Environmentally Responsible and Healthy Food Systems
### Vegetarian Diets  
Vegetarianism consists of a diet free of all animal flesh, including terrestrial species, aquatic species, birds, and even insects [37]. There are different variants of vegetarian diets, such as lacto-ovo-vegetarianism (includes the consumption of dairy products and eggs), lacto-vegetarianism (includes only dairy products), ovo-vegetarianism (includes only eggs), and veganism, which does not include any derivative of animal origin [13; 38; 39]. In industrialized nations, the prevalence of individuals adopting plant-based diets has significantly increased in recent years, driven by a combination of ethical, cultural, economic, health, and environmental factors [40]. These key influences include growing concerns over animal welfare, an enhanced sense of moral satisfaction and vegetarian community belonging, heightened awareness of sustainability and therapeutic benefits, and the broader availability of information and vegan products, all of which contribute to this ongoing dietary transition, a trend expected to persist moving forward [21; 41; 42; 43; 44; 45; 46].  
Several studies have positively correlated vegetarian diets with various physiological health indicators [47; 48; 49; 50], such as a lower risk of blood cholesterol [51], type 2 diabetes [52], metabolic syndrome [53], ischemic heart disease [54], coronary artery disease [55], chronic kidney disease progression [56], prostate cancer [57], or colorectal cancer [58]. Furthermore, it has been established that vegetarian diets provide important health benefits due to their antioxidant, anti-inflammatory, immunomodulatory, anti-proliferative, and antihypertensive capacity, as well as their potential for inducing the microbial synthesis of short-chain fatty acids (SCFAs) and postbiotics, such as equal, urolithin, enterolignans, vitamins, isothi cyanates, coprostanol, and secondary bile acids [59]. However, the relationship between vegetarian diets and mental health has been studied to a lesser extent [60], and the evidence obtained to date is contradictory, which may be due to several limitations not addressed within the studies conducted [37]. In this regard, it has been suggested that this type of diet is linked to a higher incidence of anxiety, stress, and depression [61; 62; 63; 64; 65], but different findings associate this diet with higher levels of psychological well-being [67; 68; 69; 70]. In contrast, additional studies report that there is no evidence to support the causal role of vegetarian diets in mental health [71; 72; 73; 74; 75].  
Vegetarian diets are more environmentally sustainable than meat-based diets, requiring fewer resources and reducing greenhouse gas emissions, deforestation, and biodiversity loss [13; 20]. However, to promote a sustainable transition from current dietary habits to plant-based diets, it is essential to identify and address potential barriers. Important measures and interventions to promote plant-based diets include updating dietary guidelines, establishing urban gardens, fortifying foods, developing plant-based alternatives, and imposing taxes on unhealthy food products [49]. Additionally, incorporating organic and sustainable farming practices, as well as emphasizing the benefits of vegetable fermentation processes, may constitute pivotal strategies for enhancing the environmental impact and preserving the nutritional quality of plant-based foods.