Water-Only Fasting May Reduce Chemo Modifications, Hospital Admissions

April 3, 2020 10:00 am

The following article is provided by The Clearity Foundation to support women with ovarian cancer and their families. Learn more about The Clearity Foundation and the services we provide directly to women as they make treatment decisions and navigate emotional impacts of their diagnosis.

By Neil Osterweil


Patients with gynecologic malignancies who consumed only water for 24 hours before and 24 hours after each chemotherapy cycle had fewer dose delays and reductions compared with patients who didn’t fast, results of a small study showed.

The study included 23 women with ovarian, uterine, or cervical cancer, most of whom received platinum-based chemotherapy and taxanes. Fewer treatment modifications were required among the 11 patients randomized to a 24-hour water-only fast before and after each chemotherapy cycle than among the 12 patients randomized to standard care. Furthermore, there were no hospital admissions in the fasting group and two admissions in the control group, according to study author Courtney J. Riedinger, MD, of the University of Tennessee Medical Center in Knoxville.

She and her colleagues detailed the rationale and results of this study in an abstract that had been slated for presentation at the Society of Gynecologic Oncology’s Annual Meeting on Women’s Cancer. The meeting was canceled because of the COVID-19 pandemic. Data have been updated from the abstract.


“We decided to test water-only fasting because there’s not much data about the cell-fitness effects of fasting” on chemotherapy outcomes, she said.

Pre-chemotherapy fasting is based on the concept of differential stress resistance intended to protect normal cells but not cancer cells from the effects of chemotherapy. Fasting decreases levels of insulin-like growth factor 1, which leads healthy cells to enter a protective state by decreasing cell growth and proliferation. Cancer cells, in contrast, cannot enter the protective state, and are therefore more vulnerable than healthy, quiescent cells when exposed to drugs that target the cell cycle, Dr. Riedinger and colleagues noted.

The second study showed that breast and ovarian cancer patients had improved quality of life scores and decreased fatigue when they fasted for 36 hours before and 24 hours after a chemotherapy cycle (BMC Cancer;18: article 476).

Study details

Dr. Riedinger and colleagues conducted a nonblinded, randomized trial of fasting in women, aged 34-73 years, who had gynecologic malignancies treated with a planned six cycles of chemotherapy. The patients were instructed to maintain a water-only fast for 24 hours before and 24 hours after each cycle. Controls did not fast.

In all, 92% of chemotherapy cycles were completed with fasting as directed.

There were no significant differences in any of the study measures between patients who fasted and those who did not. However, this study was not powered to detect a difference, according to Dr. Riedinger.

Still, there were trends suggesting a benefit to fasting. Fasting patients had a higher mean change in NCCN-FACT FOSI-18 score compared with controls – increases of 5.11 and .22, respectively.

Five patients in the fasting group required changes to their treatment regimen, compared with eight patients in the control group. In addition, there were no hospital admissions in the fasting group and two admissions in the control group.

Patients tolerated the fast well without significant weight loss, and there were no grade 3 or 4 toxicities among patients who fasted.

The investigators are planning a larger study to further evaluate the effect of fasting on quality of life scores and treatment, and to evaluate the effects of fasting on hematologic toxicities. Future studies will focus on the optimal duration of fasting and the use of fasting-mimicking diets to allow for longer fasting periods, Dr. Riedinger said.

The study was internally funded. The authors reported no conflicts of interest.

SOURCE: Riedinger CJ et al. SGO 2020. Abstract 22.

This article was published by MDedge.

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