Association of Soyfoods or Soybean Products Consumption with Psychological Symptoms: Evidence from a Cross-Sectional Study of Chinese University Students during the COVID-19 Pandemic

There is a strong association between soyfoods or soybean product consumption and adolescent health, but there are few studies on the association between soyfoods or soybean product consumption and psychological symptoms among university students. To this end, this study investigated the association between soyfoods or soybean products consumption and psychological symptoms among Chinese university students and analyzed the association between them. A three-stage stratified whole-group sampling method was used to administer questionnaires on soyfoods or soybean products consumption and psychological symptoms to 7742 university students in China. Self-assessment questionnaires were also administered to confounding variables such as basic demographic information, family status, parental education, body mass index (BMI), and moderate and vigorous physical activity (MVPA). The chi-square test, one-way ANOVA, and logistic regression analysis were used to explore the association and differences between soyfoods or soybean products consumption and psychological symptoms. The proportion of Chinese university students' soyfoods or soybean products consumption in ≤one time/week, two-four times/week, and ≥five times/week were 38.81%, 40.24%, and 20.95%, respectively. University students' psychological symptoms problem detection rate was 16.22%. The detection rate of psychological symptoms was lower among university male students (14.75%) than female students (17.35%), and the difference was statistically significant (χ² = 9.525, p < 0.01). After adjusting for relevant covariates, students with soyfoods or soybean products consumption ≤one time/week (OR = 1.83, 95% CI:1.52, 2.21) had a higher risk of psychological symptoms compared to university students with soyfoods or soybean products consumption ≥five time/week (p < 0.01). During the COVID-19 pandemic, Chinese university students had lower consumption of soyfoods or soybean products and a higher detection rate of psychological symptoms. There was a negative association between soyfoods or soybean products consumption and psychological symptoms. Our study provides a scientific reference for the government and educational decision-making authorities and suggests that education on eating behavior and dietary guidance should be emphasized among university students in the future to maintain a reasonable consumption of soyfoods or soybean products for better physical and mental health development.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

Perspective: Soybeans Can Help Address the Caloric and Protein Needs of a Growing Global Population

Feeding a growing global population with projected rising socioeconomic status will require additional sources of calories and especially protein. These sources need to align with the Sustainable Development Goals established by the Food and Agriculture Organization of the United Nations. The soybean is uniquely positioned to meet this challenge based on the following criteria: (1) Global soybean production exceeds by ~4 times the production of all pulses combined (2) Soybeans are higher in protein than other legumes and soy protein quality is similar to animal protein quality (3) Soybeans are an excellent source of healthy fat, including both essential fatty acids (4) Soybeans, like other legumes, symbiotically fix atmospheric nitrogen thereby reducing the need for fertilizer inputs (5) Greenhouse gas emissions per unit protein are lower than for nearly all other foods (6) Soybeans, like other legumes, are also recognized as an affordable food that can be incorporated into diverse diets regardless of economic standing and (7) The range of foods produced from soybeans constitutes an important position in historic and contemporary cuisines, cultures and emerging consumer trends for plant-based protein. Although most soybeans are currently used for animal feed, soybean use is dictated by consumer demand. Therefore, soybeans are well positioned to meet future global needs for energy and protein. Armed with this knowledge, health professionals can feel justified in encouraging greater consumption of soyfoods for both personal and planetary reasons.

Health impact of childhood and adolescent soy consumption

Soyfoods have been intensely researched, primarily because they provide such abundant amounts of isoflavones. Isoflavones are classified as both plant estrogens and selective estrogen receptor modulators. Evidence suggests that these soybean constituents are protective against a number of chronic diseases, but they are not without controversy. In fact, because soyfoods contain such large amounts of isoflavones, concerns have arisen that these foods may cause untoward effects in some individuals. There is particular interest in understanding the effects of isoflavones in young people. Relatively few studies involving children have been conducted, and many of those that have are small in size. While the data are limited, evidence suggests that soy does not exert adverse hormonal effects in children or affect pubertal development. On the other hand, there is intriguing evidence indicating that when soy is consumed during childhood and/or adolescence, risk of developing breast cancer is markedly reduced. Relatively few children are allergic to soy protein, and most of those who initially are outgrow their soy allergy by 10 years of age. The totality of the available evidence indicates that soyfoods can be healthful additions to the diets of children, but more research is required to allow definitive conclusions to be made.

Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature

Soyfoods have long been recognized as sources of high-quality protein and healthful fat, but over the past 25 years these foods have been rigorously investigated for their role in chronic disease prevention and treatment. There is evidence, for example, that they reduce risk of coronary heart disease and breast and prostate cancer. In addition, soy alleviates hot flashes and may favorably affect renal function, alleviate depressive symptoms and improve skin health. Much of the focus on soyfoods is because they are uniquely-rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. Despite the many proposed benefits, the presence of isoflavones has led to concerns that soy may exert untoward effects in some individuals. However, these concerns are based primarily on animal studies, whereas the human research supports the safety and benefits of soyfoods. In support of safety is the recent conclusion of the European Food Safety Authority that isoflavones do not adversely affect the breast, thyroid or uterus of postmenopausal women. This review covers each of the major research areas involving soy focusing primarily on the clinical and epidemiologic research. Background information on Asian soy intake, isoflavones, and nutrient content is also provided.