S-equol is a compound formed in the gut after consuming soy products. This metabolite plays a role in the body’s processes.
The Production of S-equol in the Body
S-equol is a metabolite of daidzein, a soy isoflavone. It is produced in the human gut by specific bacteria. This conversion highlights the gut microbiota’s influence on how the body uses soy compounds.
Only 25% to 50% of the global population can metabolize daidzein into S-equol. This ability varies, with approximately 50% to 60% of adults in Asian countries like Japan, Korea, and China being producers, compared to 25% to 30% in Western countries. Dietary habits and geographical location influence this ability. Higher daidzein intake may be associated with an increase in specific intestinal bacteria responsible for equol production.
How S-equol Functions
S-equol is a non-steroidal compound that structurally resembles estrogen, enabling it to interact with estrogen receptors. These receptors act as “docks” on cells where hormones like estrogen attach to trigger cellular responses. S-equol can fit into these docks, initiating its own effects.
S-equol is recognized as a selective estrogen receptor modulator (SERM) or a phytoestrogen. Phytoestrogens are plant-derived compounds that can exert estrogen-like effects. S-equol exhibits a strong affinity for estrogen receptor beta (ERβ), binding more strongly than to estrogen receptor alpha (ERα). This preferential binding contributes to its selective actions in different body tissues.
Researched Health Effects
Research has explored several potential health effects of S-equol, particularly in areas influenced by hormonal balance. Its impact on menopausal symptoms is a key area of study. Clinical trials, including randomized, placebo-controlled studies, indicate that S-equol supplementation may help alleviate hot flashes and night sweats, common symptoms during menopause. For example, a 12-week trial reported that 90% of women experienced improvement in menopausal symptoms, including hot flashes and night sweats.
S-equol has also been investigated for skin health. A pilot randomized placebo-controlled trial involving postmenopausal Japanese women examined S-equol’s impact on skin aging. After 12 weeks, participants receiving 10 mg or 30 mg of S-equol daily showed significant reductions in crow’s-feet wrinkles and wrinkle depth compared to the placebo group. These findings suggest a potential role for S-equol in supporting skin appearance.
In the context of bone density, S-equol offers benefits, especially for postmenopausal women. A one-year double-blind, placebo-controlled trial found that 10 mg of S-equol per day significantly inhibited bone resorption, a process of bone breakdown, and prevented a decrease in whole-body bone mineral density in postmenopausal women. This effect is partly attributed to S-equol’s interaction with estrogen receptor beta (ERβ), which is abundant in bone tissues.
S-equol has shown promise in prostate health research. Studies suggest it can act as an anti-androgen by binding to dihydrotestosterone (DHT), a potent male hormone, preventing DHT from binding to androgen receptors. This mechanism may contribute to its observed ability to reduce prostate growth and decrease prostate-specific antigen (PSA) levels.
S-equol Supplements
For individuals who do not naturally produce S-equol from soy isoflavones, supplementation offers a way to obtain this compound. S-equol supplements are available, typically derived through the fermentation of soy germ using specific bacteria to produce the biologically active form.
Dosages in S-equol supplement studies have varied, with many trials using 10 mg daily, though some research suggests greater benefits at higher doses, such as 40 mg or up to 200 mg. Given its half-life of 7 to 10 hours, S-equol is often recommended for twice-daily administration to maintain consistent levels. S-equol’s safety profile has been assessed; it is generally well-tolerated, with no serious adverse events reported in clinical studies lasting up to one year. Mild side effects such as constipation and bloating have been noted.