Longevity & AgingFasting Supercharges Breast Cancer Treatment Through a Hidden Hormone Switch
Researchers discovered that periodic fasting enhances tamoxifen efficacy in estrogen receptor-positive breast cancer by triggering a large-scale epigenetic shift that activates glucocorticoid receptor (GR) and progesterone receptor signaling inside tumors. Using mouse xenograft models, multiomics profiling, and clinical patient data, the team showed GR nuclear translocation is a key driver of fasting's anti-tumor effect. Crucially, administering exogenous GR ligands (corticosteroids) replicated fasting's tumor-suppressing benefits without requiring dietary restriction. Patients on a fasting-mimicking diet showed elevated blood cortisol and progesterone, and their tumor biopsies confirmed GR activation correlated inversely with proliferation markers—bridging animal findings to human biology.
