Dinner Hour and Sleep Habits Affect Risk of Breast, Prostate Cancers
Long-term disruptions of natural human cycles have been associated with increased risk of cancer.
Eating dinner earlier and going to bed at least 2 hours after eating were associated with decreasing the risk of breast and prostate cancers, according to study findings published in the International Journal of Cancer.
Evidence suggests that long-term disruptions of natural human cycles — such as circadian rhythm due to shift work — may lead to adverse outcomes such as diabetes, obesity, cardiovascular disease, and cancer, particularly of the breast and prostate. The effect of timing of eating on health risks, however, have yet to be fully understood.
For the MCC-Spain, population-based, case-control study, researchers analyzed 1205 patient with breast cancer and 621 patients with prostate cancer, also including 872 men and 1321 women as controls. Eligible patients had never worked night shifts, were interviewed on the timing of their meals, sleep, chronotype (a genetic basis for preference of daytime or nighttime activity), and completed a Food Frequency Questionnaire. Patient adherence to the World Cancer Research Fund/American Institute of Cancer Research recommendations for cancer prevention was also assessed.
Results showed that those who waited 2 or more hours after eating supper to sleep had a 20% reduced risk for breast and prostate cancers combined compared with participants who went to sleep immediately after dinner. Participants who reported eating dinner earlier — before 9 pm—also had similar reductions in risk compared with those who ate after 10 pm.
These benefits were more pronounced among patients who adhered to the cancer prevention recommendations, as well as in patients who were identified as morning chronotype.
The researchers concluded that “adherence to a more diurnal eating pattern and specifically a long interval between last meal and sleep is associated with a lower cancer risk. The hypothesis we tested is supported by experimental evidence and stresses the importance of evaluating circadian rhythms in studies on diet and cancer.”
Kogevinas M, Espinosa A, Castello A, et al. Effect of mistimed eating patterns on breast and prostate cancer risk (MCC‐Spain Study)[published online July 17, 2018]. Int J Cancer. doi: 10.1002/ijc.31649