Dietary patterns and the testosterone–estrogen axis in men: evidence from osteoporotic fractures in men and a systematic review

Diet may influence circulating sex steroid hormones, but evidence for overall dietary patterns remains limited. We examined associations of dietary patterns reflecting lower inflammatory potential, lower insulinaemic potential and higher overall diet quality, with circulating sex steroids in older men and systematically reviewed the literature in apparently healthy men published through June 2024. We conducted cross-sectional analyses of 1622 men aged ≥65 years from the Osteoporotic Fractures in Men Study. Diet was assessed using FFQ and sex hormone-binding globulin (SHBG), total and free testosterone and total and free estradiol were measured. Dietary patterns included the reversed Empirical Dietary Inflammatory Pattern (rEDIP), reversed Empirical Dietary Index for Hyperinsulinaemia (rEDIH) and Healthy Eating Index-2020 (HEI-2020). Among older men, each 1-standard deviation increase in rEDIP was associated with higher total testosterone ( β = 2·15; 95 % CI 0·12, 4·18) and free testosterone ( β = 2·02 ng/dL; 95 % CI 0·29, 3·75), whereas rEDIH showed similar but non-significant associations with total testosterone ( β = 1·64; 95 % CI –0·28, 3·57) and free testosterone ( β = 1·43; 95 % CI –0·21, 3·08). Higher HEI-2020 scores were associated with higher free estradiol ( β = 2·46 pg/mL; 95 % CI 0·85, 4·07). Across twenty-one studies, healthier dietary patterns were generally associated with lower estradiol and higher concentrations of SHBG and total testosterone. Taken together, the individual-level analyses and systematic review suggest that anti-inflammatory, low-insulinaemic and overall healthy dietary patterns are associated with more favourable sex steroid hormone profiles in men, although prospective studies are needed to establish temporality.