Short overnight fasting linked to increased risk of breast cancer recurrence

http://www.eurekalert.org/pub_releases/2016-03/uoc--sof032916.php

Public Release: 31-Mar-2016
Short overnight fasting linked to increased risk of breast cancer recurrence
Researchers suggest increasing duration of nightly fasting may improve prognosis
University of California - San Diego

In patients with breast cancer, a short overnight fast of less than 13 hours was associated with a statistically significant, 36 percent higher risk of breast cancer recurrence and a non-significant, 21 percent higher probability of death from the disease compared to patients who fasted 13 or more hours per night, report University of California, San Diego School of Medicine researchers.

The study, publishing online in the Journal of the American Medical Association Oncology on March 31, also found a non-significant, 22 percent higher risk of mortality from any cause among patients with breast cancer who fasted for shorter periods compared to those who fasted for 13 hours or more overnight.

Researchers also reported that fasting fewer hours per night was associated with significantly less sleep and higher levels of glycated hemoglobin (HbA1c), which is a measure of average blood sugar levels over a period of months. These findings are relevant to cancer prevention and control efforts because elevated HbA1c and poor sleeping habits have been linked to an increased risk of breast cancer. These findings corroborate a paper published in April 2015, in which researchers demonstrated that shorter overnight fasts were associated with worse blood sugar control.

"Prolonging the overnight fasting interval may be a simple, non-pharmacological strategy for reducing a person's risk of breast cancer recurrence and even other cancers," said Catherine Marinac, lead author and doctoral candidate at UC San Diego Moores Cancer Center. "Previous research has focused on what to eat for cancer prevention, but when we eat may also matter because it appears to affect metabolic health."

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Randomized trials to test whether prolonging overnight fasting reduces the risk of chronic diseases are needed, said the authors.