Sleep and Circadian Function

BRP has identified sleep health as a priority area of research given the emerging evidence of its role in the prevention, treatment, and management of cancer. Research with populations suffering from sleep deprivation (e.g., military personnel), occupational sleep disruptions (e.g., shift workers), and sleep disorders (e.g. sleep apnea patients) demonstrates the influence of sleep on day-to-day functioning, as well as long term health outcomes, including cancer risk.

Possible mechanisms linking sleep health and cancer include immune functioning and inflammatory processes, both of which can be modulated by sleep quality, timing, and duration. Epidemiologic studies involving healthy populations have most commonly studied one aspect of sleep health – average sleep duration. These studies have found clear associations between self-reported short sleep duration and long-term health outcomes such as cancer, diabetes, obesity, depression, hypertension, and all-cause mortality. 

Research also points to possible mediating and moderating effects of sleep on health determinants (e.g., physical activity, diet, tobacco use, and alcohol consumption). For instance, poor sleep may lead to poor decision making around behaviors that increase (e.g., smoking) or decrease (e.g., exercise) cancer risk.

The effects of sleep on daily decision making may influence a wide range of cancer outcomes, including decisions about information sharing, genetic testing, treatment, and palliative care. Conversely, other health behaviors will affect sleep health, so it is important to understand the bi-directional relationship.

It is also important to take a longitudinal approach to sleep health because sleep varies within individuals over time. Studying these processes as they unfold over time within individuals will yield a richer understanding of the relationship between sleep health and cancer. Research that improves our understanding of the relationship between sleep health and cancer will allow us to better support the development and implementation of cancer prevention and control interventions for healthy populations, cancer patients and survivors.