Physiologically Active Molecules and Functional Properties of Soybeans in Human Health—A Current Perspective

Abstract

In addition to providing nutrients, food can help prevent and treat certain diseases. In particular, research on soy products has increased dramatically following their emergence as functional foods capable of improving blood circulation and intestinal regulation. In addition to their nutritional value, soybeans contain specific phytochemical substances that promote health and are a source of dietary fiber, phospholipids, isoflavones (e.g., genistein and daidzein), phenolic acids, saponins, and phytic acid, while serving as a trypsin inhibitor. These individual substances have demonstrated effectiveness in preventing chronic diseases, such as arteriosclerosis, cardiac diseases, diabetes, and senile dementia, as well as in treating cancer and suppressing osteoporosis. Furthermore, soybean can affect fibrinolytic activity, control blood pressure, and improve lipid metabolism, while eliciting antimutagenic, anticarcinogenic, and antibacterial effects. In this review, rather than to improve on the established studies on the reported nutritional qualities of soybeans, we intend to examine the physiological activities of soybeans that have recently been studied and confirm their potential as a high-functional, well-being food.

Current Perspectives on the Beneficial Effects of Soybean Isoflavones and Their Metabolites for Humans

“…Activation of NF-κB inhibits apoptosis, whereas inhibition of isoflavones-induced NF-κB enhances apoptosis in human cancer cells, suggesting that isoflavones play critical roles in the apoptotic pathway by inhibiting NF-κB signaling [147]. Figure adapted from Kim et al [8].…”

“…Asian countries consume isoflavones in tofu, tempeh, miso, natto, and cheonggukjang; in Western countries, it is mainly consumed in the form of dairy substitutes, such as soy milk, soy cheese, and soy yogurt [7,8]. Isoflavones occur in food as either sugarbound glycosides or as aglycones, without a sugar molecule; aglycones are known to be more bioavailable than glycosides [9].…”

Beneficial Effects of Soybean-Derived Bioactive Peptides

“…The soy amino acids are well absorbed by the body, and the hydrophobic amino acids are broken down at the C or N terminal ends, which reduces the bitter taste. Moreover, SPs have strong gel-forming properties that, in turn, reinforce its foaming and emulsifying activities [4]. By regulating bile acids reabsorption within digestive systems or organs SPs can effectively lower blood cholesterol levels and decrease low-density lipoprotein (LDL) and fat accumulation, which supports their use for the prevention and treatment of arteriosclerosis [39,40].…”

“…Soybeans contain phytochemicals that possess anticancer, antiaging, antirenal failure, antiobesity, and anticholesterolemic activities. These phytochemicals can also inhibit HIV; prevent gallstone formation, senile dementia, and hyperlipidemia; promote diuretic action; suppress arteriosclerosis, provide relief from constipation; and prevent cardiovascular disease [4][5][6][7]. Therefore, soybeans are involved in the prevention of chronic diseases.…”

“…Therefore, soybeans are involved in the prevention of chronic diseases. Soybeans also contain substances that contribute to intestinal regulation, exert antioxidative properties, prevent osteoporosis, lower blood pressure, exert antithrombotic effects, boost immunity, and promote liver function [4,8,9].…”