Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse models.
Level 5 - mechanism / opinion, no new human data
Animal research with no human participants.
PubMed 33495474 · doi:10.1038/s41467-020-20743-7
What was done
Researchers evaluated the effect of time-restricted feeding (TRF) on mouse models of obesity-driven postmenopausal breast cancer. They tested TRF in two orthotopic mammary tumor models and a transgenic model of mammary tumorigenesis (prior to obesity onset) to evaluate tumor growth, lung metastasis, and tumor initiation compared to controls. They also measured changes in insulin sensitivity, hyperinsulinemia, diurnal gene expression rhythms in tumors, and insulin signaling, and tested causality by administering the insulin-secretion inhibitor diazoxide or implanting insulin pumps to elevate insulin levels.
What was found
The abstract reports findings qualitatively without numeric data. TRF abrogated obesity-enhanced mammary tumor growth across two orthotopic models without causing calorie restriction or weight loss, reduced breast cancer metastasis to the lung, and delayed tumor initiation in the transgenic model. TRF increased whole-body insulin sensitivity, reduced hyperinsulinemia, restored diurnal gene rhythms in the tumor, and attenuated tumor growth and insulin signaling. Pharmacological inhibition of insulin secretion with diazoxide mimicked TRF effects, whereas artificial elevation of insulin via pump implantation reversed the protective effects of TRF.
Why it matters
This work demonstrates that hyperinsulinemia is a critical driver of obesity-associated mammary tumor growth and that TRF can mitigate tumor progression in preclinical models without requiring weight reduction. If translated to clinical settings, TRF could represent a feasible dietary strategy to lower breast cancer risk or improve outcomes in postmenopausal individuals.
Limits
This study was conducted entirely in mouse models, and findings may not directly translate to human postmenopausal breast cancer. The abstract does not provide sample sizes, quantitative effect sizes, duration of the daily fasting window, or survival data. Potential long-term adverse effects or feasibility in clinical populations were not assessed.
Cited by
- supports Tumors grow slower in mice subjected to time-restricted feeding compared to mice eating the same number of calories ad libitum.