Could fasting revolutionize breast cancer treatment? A new study sparks hope—and debate.
A groundbreaking study published in Nature on December 10, 2025, explores how fasting might enhance hormone therapy for breast cancer—but here’s where it gets controversial: the research, conducted primarily in mice, raises as many questions as it answers. The findings suggest that metabolic changes during fasting could amplify the effectiveness of hormone therapy in estrogen-receptor-positive breast cancer, a development that has experts both excited and cautious.
Dr. Charlie Birts, Lecturer in Antibody Therapeutics at the University of Southampton, praised the study’s design and depth. He highlighted its use of genomic and functional approaches, particularly the consistent activation of glucocorticoid and progesterone receptor pathways across models. ‘This opens the door to exciting possibilities,’ Dr. Birts noted, ‘like fasting-mimicking strategies or glucocorticoid-based treatments.’ But he also sounded a note of caution: ‘This is preclinical work, and the human data, though promising, is preliminary and lacks control groups.’
One of the most intriguing—and debated—aspects of the study is its use of immuno-deficient mouse models. While these models provide valuable insights, they limit our understanding of how fasting or glucocorticoid signaling interacts with the immune system in real-world cancer patients. ‘And this is the part most people miss,’ Dr. Birts added, ‘key variables like estrogen levels and tamoxifen metabolite exposure weren’t measured, leaving us to wonder how much of the effect is due to direct mechanisms versus broader hormonal changes.’
Dr. Dimitrios Koutoukidis, Associate Professor in Diet, Obesity, and Behavioural Sciences at the University of Oxford, echoed these concerns. ‘While the study provides a foundation for future research on dietary restrictions in cancer patients, it’s too early to draw conclusions about fasting-mimicking diets in humans,’ he said. ‘The human data is simply too limited.’
The study, titled ‘Fasting boosts breast cancer therapy efficacy via glucocorticoid activation’ by Nuno Padrão et al., has already sparked discussions about the potential of fasting mimetics in cancer treatment. But the big question remains: Will these findings translate into tangible benefits for patients? Both experts agree that clinical recommendations should stay put until robust human trials are completed.
Controversy Alert: Should we be cautiously optimistic about fasting as a complementary cancer therapy, or is it too soon to even consider it? Let’s hear your thoughts in the comments—do you think fasting could play a role in future cancer treatments, or is this just another overhyped trend?
Publication Details:
‘Fasting boosts breast cancer therapy efficacy via glucocorticoid activation’ by Nuno Padrão et al. was published in Nature at 16:00 UK time on Wednesday, December 10, 2025. DOI: 10.1038/s41586-025-09869-0.
Declared Interests:
- Dr. Dimitrios Koutoukidis: No conflicts of interest.
- Dr. Charlie Birts: ‘I have no conflicts of interest to declare.’
For all other experts, no response to our request for conflict declarations was received.
