Pilot study to assess prolonged overnight fasting in breast cancer survivors (longfast)
Elizabeth O'Donnell1, Yael Shapiro2, Amy Comander2
1Harvard Medical School, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA. ekodonnell@mgh.harvard.edu.
Purpose:
Retrospective analysis of nightly fasting among women with breast cancer suggests that fasting < 13 h may be associated with a higher risk of breast cancer recurrence. We sought to evaluate prolonged overnight fasting (POF), an accessible nonpharmacological intervention, in a prospective feasibility study.
Methods:
We designed a single-arm, pilot study to evaluate the feasibility of fasting for 13 h overnight for 12 weeks among women with a history of early-stage breast cancer survivors. Baseline and end of study assessments included measurements of body mass index (BMI), blood biomarkers, quality of life (QOL), mood, fatigue, and physical activity. Patient-reported outcome questionnaires were also administered at 6 weeks. Feasibility was defined as ≥ 60% of participants documenting fasting for 13 h on at least 70% of nights during the study period.
Results:
Forty women with a history of breast cancer were enrolled with a median age of 60 (range 35-76) and median time since diagnosis of 4.5 years (range 0.8-20.7). At baseline, BMI was ≥ 25 in 37.5%. Ninety-five percent of participants fasted ≥ 13 h for at least 70% of study days (95% CI 83-99%). There was a statistically significant improvement in anxiety (p = 0.0007) at 6 weeks and BMI (p = 0.0072), anxiety (p = 0.0141), depression (p = 0.0048), and fatigue (p = 0.0105) at 12 weeks. There was no significant change in overall QOL, physical activity levels, or blood biomarkers at 12 weeks.
Conclusions:
POF is feasible among patients with a history of breast cancer and may potentially improve BMI, mood, and fatigue without detrimental effects on overall QOL.
