Red clover is a perennial herb found in Europe, the United States and New Zealand. Red clover has traditionally been considered a respiratory antispasmodic. The estrogenic effect of red clover species was observed during livestock farming, and after research, the isoflavonoid-related effects of red clover were discovered, which stimulated the development and marketing of dietary supplements from the red clover plant.
Red clover is rich in isoflavones, flavonoids and flavonols, of which isoflavones are the more concerned efficacy component. Plant isoflavones are almost entirely produced in legumes, and the more common one is soy isoflavones.
Compared with soy isoflavones, the monomeric composition of red clover isoflavones seems to be more comprehensive, with prickly mangosteen and chickpea A (a type of isoflavone) being higher than soy isoflavones, while the content of luteolin and genistein is lower. Meanwhile, red clover isoflavones basically do not contain protein, which also avoids allergic reactions during practical application.
Estrogen plays an important role in women at all ages, and during the perimenopause, the decline of estrogen, especially 17β-estradiol, produces various menopausal symptoms such as bone loss, hot flashes, and accompanying metabolic disorders of blood lipids or blood pressure, and phytoestrogen replacement becomes a good option for nutritional care.
Phytoestrogens are secondary metabolites that induce biological responses in vertebrates and can mimic or modulate the effects of endogenous estrogens, usually by binding to estrogen receptors (ERs).
ERs are steroid receptors and ERs consist of two subtypes ERα and ERβ on the cell membrane, similar to the body's own steroidal estrogens. ERβ plays an important regulatory role in the metabolism of the body's bones, while mammary and uterine tissues are influenced by ERα estrogens, thus the different distribution of estrogen receptors offers the possibility to target specific tissues.
Red clover isoflavones are structurally similar to endogenous 17β-estradiol, which has a higher affinity for ER-β compared to ER-α. In addition, several non-hormonal effects of isoflavones have been reported, including inhibition of tyrosine kinases, antioxidant activity and effects on ion transport.
The United Nations World Health Organization estimates that there will be 1.2 billion menopausal or post-menopausal women worldwide by 2030, and the global nutraceutical market for women with menopausal symptoms is expected to exceed $50 billion in 2025, growing at a CAGR of 16.4% from 2016-2025.
The top-ranked ingredients for food use are soy isoflavones, estradiol, red clover, and black asclepias extract, but in China people use more soy isoflavones and compound some traditional medicinal ingredients, such as angelica and Pueraria Mirifica.
According to Global information, Inc. survey, the global isoflavones market will reach $1.3 billion in 2020 and is forecast to maintain a CAGR of 4.7%, mainly in the dietary supplement and cosmeceutical markets.
And DATAINTELO expects the global red clover market to grow at a rate of 13.7% from 2020-2026, exceeding the growth of the isoflavones market, indicating that the growth of red clover isoflavones is driving the global isoflavones market, with its growth attributed to its nutritional health and medical purposes.
Red clover isoflavones have been used for a long time in Europe and the United States, but due to geographical and regulatory reasons, they are not widely used in China and are in the emerging stage. However, its composition is similar to that of soy isoflavones, and its application range is more extensive, which can provide product designers with more differentiated options.
