Evaluation of plant and animal protein consumption within the scope of sustainable nutrition and ıts relationship with depression, anxiety and stress

Abstract

Introduction and Aim: Depressive disorder is seen in 4.4% and anxiety disorder in 3.6% of adults in the world. As a result of the rapid increase in the population, there has been a serious increase in the rates of depression, anxiety and stress, especially at young ages (1). Although there are various treatment methods such as pharmacotherapy and psychotherapy for these psychiatric disorders, it is known that they are effective in only less than half of the disease burden. Therefore, additional strategies are needed for treatment (2,3). It is thought that the diet of individuals affects their psychological and mental state. In this context, various amino acids, which act as precursors of neurotransmitters, have significant effects on brain functions and mood at the same time (4). When the literature is examined, it is seen that the results of the studies investigating the relationship between protein consumption and depression, anxiety and stress are not clear. In the literature, studies evaluating the effects of plant or animal protein on depression, anxiety and stress levels are insufficient. In addition, the study of the effect of dietary protein (plant or animal) on the psychological state is also interesting in terms of the concept of sustainable nutrition, which has attracted a lot of attention in recent years. Within the scope of sustainable nutrition, it is recommended to limit the consumption of animal-based foods that increase greenhouse gas emissions, and instead prefer plant-based foods to meet their needs. In the study, it was aimed to evaluate the effect of plant and animal protein on depression, anxiety and stress levels within the scope of sustainable nutrition.

Material and Method: The research was carried out with 225 students studying at Biruni University Faculty of Health Sciences in Istanbul. The "Data Collection Form", which includes questions about sociodemographic information, general health and eating habits, "Short Form of Depression-Anxiety-Stress Scale" to determine depression, anxiety and stress level, "Sustainable and Healthy Eating Behaviors Scale" to determine sustainable eating behaviors, “Food Consumption Frequency” to determine the consumption frequency of food groups, and “24-Hour Retrospective Food Consumption Record” forms were applied to evaluate the food consumption of the previous day. All data were analyzed with SPSS 27.0.1 statistical program.

Results: In the study, it was found that individuals with severe depression levels had lower scores in the "healthy and balanced nutrition" sub-dimension of the sustainable and healthy eating behaviors scale compared to normal individuals, and also individuals with extremely severe depression levels had lower scores in the "Quality marks (local and organic)" and "Animal health" sub-dimensions compared to normal individuals (p<0.05). It was observed that the individuals in the severe stress group had a lower level of knowledge in the "Local food" sub-dimension compared to the individuals in the mild stress and normal group (p<0.05). According to the frequency of food consumption data, it was determined that the consumption of dairy did not have a significant effect on depression, anxiety and stress levels (p>0.05). It was found that those who consumed fish every day had lower depression, anxiety and stress scores compared to those who consumed fish less frequently and/or those who never consumed fish (p<0.05). It was determined that individuals who consumed chickpeas once a month had a higher depression score compared to individuals who consumed chickpeas 4-6 times a week (p<0.05).

Discussion and Conclusion: In this study, it was determined that individuals with severe depression and stress levels had lower levels of knowledge in various sustainable and healthy eating behavior sub-dimensions compared to normal individuals. It has been determined that fish, among animal-based proteins, is effective in reducing depression, anxiety and stress. It was also found that consuming chickpeas, which is a source of plant based protein, more frequently was effective in reducing depression levels. It has been determined that the frequency of consumption of foods such as dairy products, lentils, beans and peas, red meat, chicken, processed meats such as salami, sausage, has no effect on depression, anxiety and stress. Smith et al. found that young women who ate two or more fish per week had a 25% lower risk of depression during the follow-up period compared to those who ate less than two fish per week (5). In a study conducted in Turkey, it was observed that the frequency of consumption of fish and legumes decreased significantly in healthcare workers with high levels of burnout (6). Aucoin et al. reported that legume and fish consumption did not have a statistically significant effect on depression symptoms (7). Anjom-Shoae et al. reported that legume consumption was associated with lower anxiety rates in men, but no significant effects were observed in women (8). In another study, it was stated that there is a significant relationship between moderate legume consumption and depression (9). As in our study, another study reported that a diet rich in milk and dairy products did not have a statistically significant effect on the risk of depression symptoms (10). However, there are also studies in the literature showing that total protein intake and protein from milk and dairy products can reduce the risk of depression symptoms in adults (11-14). In conclusion, in our study, individuals with severe depression and stress levels have lower levels of knowledge of sustainable eating behavior. In addition to animal proteins such as fish and plant-based proteins such as chickpeas are also effective in reducing depression. Considering the importance of both preventing depression and sustainable nutrition, it is recommended to encourage adequate consumption of fish and legumes.