Influence of dietary interventions and nutrients on oestrogen dominance in males: A systematic review

As males age, declining testosterone levels may result in a relative hormonal imbalance, often described as “estrogen dominance.” Up to 30% of males aged ≥60 years experience low testosterone levels which can alter the testosterone-to-oestrogen ratio and contribute to associated symptoms. This systematic review examines the relationship between diet, nutrients, and oestrogen dominance in males exploring their potential as accessible interventions for chronic conditions linked to oestrogen imbalance in both males and females. The review focuses on identifying specific foods and nutrients influencing oestrogen dominance in males, while recognising that findings may have broader implications for females. Data sources included PubMed, AMED, SCOPUS, and CINAHL from 2000 to 2024. Twelve studies met the inclusion criteria. All studies were independently screened by two reviewers with discrepancies resolved by a third. Primary outcomes included: (1) evidence of reduced oestrogen levels, (2) evidence of increased oestrogen levels, (3) no significant change in oestrogen levels. Secondary outcomes included sex hormone binding-globulin, aromatase activity and progesterone levels. The protocol was prospectively registered in PROSPERO (registration number: CRD42024582893). A total of 766 citations were identified from which 12 relevant studies were analysed. Seven studies demonstrated reduced oestrogen levels following consumption of coffee, ergocalciferol, D-chiro-inositol, soy products, and tree nuts. Two studies reported increased oestrogen levels with higher macronutrient intake, particularly albumin and after supplementation with 107 mg of isoflavones. Three studies showed no notable effect. This review highlights that dietary components and nutrients can influence oestrogen dominance in males experiencing age-related declines in testosterone levels and increased conversion of testosterone to oestrogen, with potential implications for cardiovascular, prostate and metabolic health. • As males age, declining testosterone levels can lead to a relative hormonal imbalance. • This systematic review aims to shed light on the relationship between food, nutrients and oestrogen imbalance in males. • There are accessible potential treatment options for chronic conditions related to oestrogen imbalance in both males and females. • Food and nutrients can influence oestrogen dominance in males