isoflavoneclass

Isoflavones are a class of polyphenolic flavonoids found mainly in legumes, especially soy. They feature a C6–C3–C6 skeleton with a chromen-4-one backbone and a phenyl substituent at the 3-position, which contributes to their phytoestrogen activity. The best-known members are genistein, daidzein, and glycitein.

Dietary sources include soybeans and soy products, chickpeas, and clover. In foods they often occur as glycosides and must be hydrolyzed to absorbable aglycones. Gut microbiota influence metabolism; for example, some individuals produce equol from daidzein, which may affect biological activity.

Isoflavones act as weak phytoestrogens, binding preferentially to ERβ and producing estrogenic or antiestrogenic effects depending on context. They also exhibit antioxidant activity and can modulate signaling and gene expression. Pharmacokinetics vary with microbiome composition and food matrix.

Evidence on health effects is mixed. Some studies link high soy intake with lower risks of certain cancers and cardiovascular benefits, and others show modest relief of menopausal symptoms. Safety considerations include possible effects on thyroid function at very high intake and potential interactions with medications or hormone-sensitive conditions.

Research treats isoflavones as nutritionally relevant polyphenols with potential preventive effects; they are generally safe at typical dietary levels, while supplements require cautious evaluation of benefits and risks. Regulatory status varies by jurisdiction.