Stevioside does not participate in physiological and biochemical reactions in the human body, but has certain antibacterial and antiseptic properties, making it highly safe. Numerous pharmaceutical studies have demonstrated that stevioside is non-toxic, non-carcinogenic, and safe to consume. Regular consumption can prevent hypertension, diabetes, obesity, heart disease, and dental caries, making it an ideal sweetener to replace sucrose.
Preventing Diabetes
Stevioside cannot be broken down and digested by enzymes in the human digestive tract. Ingested stevioside passes through the stomach and small intestine into the colon, where it is fermented and utilized by intestinal microorganisms to produce short-chain fatty acids. The calorific value of stevioside is indirectly generated by short-chain fatty acids, approximately 6.3 kJ/g. The indigestibility of stevioside means that its ingestion does not increase blood sugar levels or insulin levels, making it suitable for diabetic patients. Jeppesen PB et al., using diabetic mice as experimental subjects, found that stevioside has a direct insulinotropic effect on isolated pancreatic islets and β-cells, significantly lowering blood sugar levels and inhibiting glucagon secretion. Gregersen et al. administered steviol glycosides to patients with type 2 diabetes and observed changes in blood sugar. They found that stevioside significantly reduced the post-lunch blood sugar rise and believe it could be a beneficial treatment for type 2 diabetes. Steviosides may treat type 2 diabetes by correcting α-cell dysfunction.
Preventing Hypertension
Lee CN et al. injected 25 mg/kg of stevioside into mice with essential hypertension. The mice showed a dose-dependent relaxation of antidiuretic hormone-induced vasoconstriction, indicating that stevioside has a certain antihypertensive effect. They also demonstrated that this effect may be related to its inhibitory effect on calcium influx. Wong KL et al. found that isosteviol can act on potassium channels and relax the aortic muscles of mice. Hsieh MH et al. administered stevioside to adult patients with essential hypertension for two years and found that stevioside lowered both systolic and diastolic blood pressure.
Tumor Prevention
Coudray et al., using rainbow trout as experimental subjects, found that steviol glycosides protect against epithelial cell desquamation and proliferation caused by histamine damage to the gastric mucosa. This may be due to steviosides inhibiting gastric secretions or directly inhibiting pepsin secretion. A mixture of steviosides inhibited dimethylbenz(a)anthracene-induced skin cancer in mice, demonstrating its potential to prevent tumor development. The indigestibility and non-fermentability of steviosides promote the maintenance of normal intestinal ecology, increase stool volume, and lower stool pH, offering a preventive effect against constipation and anal and rectal diseases. Furthermore, increased stool volume dilutes toxic substances in the intestine, thereby preventing the development of cancer.
Blood Lipid Regulation
Steviosides have been reported to lower blood cholesterol and triglyceride levels, reducing low-density lipoprotein (LDL) concentrations without affecting high-density lipoprotein (HDL) concentrations, thereby increasing the HDL/LDL ratio. The hypothesized reason for this reduction in blood cholesterol is that steviol glycosides effectively increase bile acid excretion and inhibit 3-hydroxy-3-methylglutaryl-CoA activity, thereby reducing cholesterol biosynthesis in the liver. The reduction in triglycerides is related to reduced lipid absorption and fatty acid synthesis.
Inhibiting Pathogens
Numerous studies have shown that steviol glycosides can promote the proliferation of bifidobacteria and lactobacilli in the human body, while inhibiting the growth of pathogens such as Escherichia coli. This mechanism of action may be that the acetic and lactic acids produced by steviol glycoside fermentation lower the intestinal pH, inhibiting the proliferation of pathogens and putrefactive bacteria in the intestine. In addition, the short-chain fatty acids produced by fermentation also inhibit the production of bacterial toxins.
Promoting Mineral Absorption
Many researchers have found that steviol glycosides can enhance the absorption of minerals, particularly calcium. This is because the fermentability of steviol glycosides lowers the intestinal pH, making calcium and magnesium soluble and more easily absorbed through epithelial cells.
