Overnight Fasting May Reduce Breast Cancer Risk in Women
A decrease in the amount of time spent eating and an increase in overnight fasting reduces glucose levels and may reduce the risk of breast cancer among women. Researchers at the University of California, San Diego School of Medicine reported these findings in Cancer Epidemiology, Biomarkers & Prevention.
The findings were also presented at the American Association for Cancer Research (AACR) Annual Meeting 2015 (Abstract 1874).
Preclinical studies have shown that daily fasting schedules aligned with sleep-wake cycles may have favorable effects on cancer risk factors and may reduce cell proliferation.
“Increasing the duration of overnight fasting could be a novel strategy to reduce the risk of developing breast cancer,” said Catherine Marinac, lead author and UC San Diego doctoral candidate. “This is a simple dietary change that we believe most women can understand and adopt. It may have a big impact on public health, without requiring complicated counting of calories or nutrients.”
Glucose Control
Women who fasted for longer periods of time overnight had significantly better control over blood glucose concentrations. The data shows that each 3-hour increase in nighttime fasting was associated with a 4% lower postprandial glucose level, regardless of how much women ate.
“The dietary advice for cancer prevention usually focuses on limiting consumption of red meat, alcohol, and refined grains, while increasing plant-based foods,” said coauthor Ruth Patterson, PhD, UC San Diego Moores Cancer Center Associate Director for Population Sciences and Program Leader of the Cancer Prevention Program. “New evidence suggests that when and how often people eat can also play a role in cancer risk.”
Women in the study reported eating five times per day with a mean nighttime fasting period of 12 hours. Those who reported longer fast durations also indicated they consumed fewer calories per day, ate fewer calories after 10:00 PM, and had fewer eating episodes.
The researchers recommended large-scale clinical trials to confirm that nighttime fasting results in favorable changes to biomarkers of glycemic control and breast cancer risk.
This study was supported by the National Cancer Institute and the NCI Centers for Transdisciplinary Research on Energetics and Cancer.
Dr. Patterson is the corresponding author for the Cancer Epidemiology, Biomarkers & Prevention article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
