Published in Critical Reviews in Food Science and Nutrition, a new review brings together the evidence behind phytoestrogens to layout their mechanisms of action, clinical benefits, research gaps and future health intervention opportunities.
“Phytoestrogens represent a promising non‑hormonal strategy for managing menopausal health, supported by evidence of benefits for vasomotor symptoms, bone metabolism, cardiovascular function and cognitive aging,” the researchers from the German Institute of Human Nutrition concluded.
However, they noted that the varying clinical outcomes underscore the need for more rigorous standardization of intervention material and clinical trial design as well as more personalized strategies informed by genetic, dietary and microbiome‑derived determinants of phytoestrogen metabolism.
“To advance clinical translation, future trials must incorporate standardized, bioavailable formulations, stratification by microbiome phenotype and metabolic status, longer durations with validated clinical endpoints, and factorial designs to isolate compound-specific effects,” they wrote. “Only through such rigor can phytoestrogens be positioned as precise, safe and effective alternatives to hormone therapy in postmenopausal health.”
Hormone mimicry
Phytoestrogens are renowned for their structural and functional resemblance to endogenous estrogen. This unique similarity allows them to interact with estrogen receptors (ERs), preferentially ER-β, which is widely expressed in skeletal, vascular, neural and gastrointestinal tissues.
Depending on the hormonal environment, they can mimic estrogen’s effects or counteract its activity, making them particularly promising in the menopausal and post-menopausal demographic, according to the review.
“By modulating estrogenic effects in tissues such as the brain, bones and cardiovascular system, phytoestrogens present a promising solution for maintaining overall health during the menopausal transition,” the authors wrote.
Beyond hormonal mimicry, research highlights the role of phytoestrogens in modulating gut microbiota, providing antioxidant benefits and influencing epigenetic regulation.
Modulating gut microbiota
The review notes research revealing a number of mechanisms behind phytoestrogens’ interaction with the gut microbiota. For example, the compounds undergo biotransformation by intestinal microflora into more bioactive metabolites.
One notable case is the soy isoflavone daidzein which is converted into equol by specific bacterial species (such as Slackia isoflavoniconvertens, Eggerthella spp., Bifidobacterium, and Lactobacillus strains). However, only a subset of individuals harbor these specific bacterial strains—people classified as “equol producers”.
Phytoestrogens can also exert prebiotic-like effects by selectively encouraging the growth of beneficial gut bacteria (such as Lactobacillus and Bifidobacterium) while suppressing harmful species. This microbial balance up-regulates tight junction proteins, strengthening the intestinal barrier, reducing permeability and preventing endotoxin leakage into blood circulation, thereby lowering systemic inflammation.
Further, microbial fermentation of phytoestrogens enhances the production of key SCFAs, including acetate, propionate and butyrate. The review noted these metabolites strengthen gut barrier tight junctions, attenuate systemic inflammation, upregulate brain-derived neurotrophic factor (BDNF) and suppress osteoclast RANKL signaling to protect bone density.
“Importantly, the gut–brain axis is also influenced by SCFAs. Butyrate has been shown to cross the blood–brain barrier, where it enhances neurotrophic signaling, specifically brain-derived neurotrophic factor (BDNF), and reduces neuroinflammation, suggesting a mechanistic link between phytoestrogen‑induced microbial shifts and cognitive health,” the authors wrote.
Antioxidant and anti-inflammatory benefits
Noting the compounds antioxidant and anti-inflammatory benefits, the review noted phytoestrogens have been found to maintain cellular redox balance by directly scavenging reactive oxygen species (ROS) and increasing the activity of key endogenous antioxidant enzymes.
“This function is particularly relevant in postmenopausal women, as estrogen deficiency leads to redox imbalance, increasing oxidative stress and accelerating age-related diseases such as cardiovascular disease, osteoporosis and neurodegenerative disorders,” the review noted.
Phytoestrogens can also stimulate Nrf2 (nuclear factor erythroid 2–related factor 2), the master transcription factor responsible for driving antioxidant gene expression and cellular resilience.
In addition, by modulating redox signaling, phytoestrogens block the activation and translocation of transcription factors such as NF-κB and AP-1. This suppresses the production of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α).
However, the authors noted prevailing concentration-dependent effects highlight the importance of dose optimization when assessing the biological and clinical activities of phytoestrogens.
Epigenetic regulation
Phytoestrogens like genistein can additionally inhibit DNA methyltransferases (DNMTs). The process reverses chemical changes that can silence tumour-suppressing genes, effectively switching on genes that help keep cell growth under control.
Isoflavones can additionally inhibit histone deacetylases (HDAC), thereby promoting hyperacetylation of certain histones and permitting the expression of genes involved in cellular homeostasis and apoptosis.
The authors said their ability to modulate epigenetic markers has been associated with reduced risks of chronic diseases, particularly hormone-dependent cancers, cardiovascular disease and metabolic disorders.
“The long-term impact of phytoestrogens on gene expression highlights their role as key dietary bioactives that can shape health outcomes through persistent molecular changes,” they wrote. “The epigenetic effects of phytoestrogens, albeit speculative, suggest that there could be transgenerational effects and this deserves more study.”
Future opportunities and white spaces
The authors noted one prevailing issue in this arena—study endpoints are frequently limited to surrogate measures, such as biomarkers or symptom-based scales, rather than hard clinical outcomes, including fracture incidence or cardiovascular events.
“This underscores the need for longer-duration, adequately powered investigations employing harmonized protocols and clinically meaningful endpoints,” they wrote.
The researchers argued the emergence of advanced validation tools will pave the way for tailored, phenotype-specific menopausal health supplement.
“As understanding of phytoestrogens evolves, integrating cutting-edge research methodologies, such as multi-omics technologies and advanced clinical trial designs, will be crucial to advancing their therapeutic potential,” they wrote, adding that the adoption of these advanced methodologies enhances the reliability of preclinical findings, facilitating the development of targeted and personalized phytoestrogen-based interventions.
“Bridging the gaps between scientific research, clinical practice, and policy will enable the full realization of phytoestrogens in promoting healthy aging, preventing chronic diseases and supporting sustainability goals,” they added.
Source: Critical Reviews in Food Science and Nutrition, https://doi.org/10.1080/10408398.2026.2728287, “Non-hormonal strategies for menopausal health: the role of phytoestrogens”, Authors: Harahap, I. A., Weber, D., & Grune, T.
