Shorter sleep duration (<6 h) was suggestively associated with a decreased risk of prostate cancer, particularly among Non-Hispanic Black men, but sleep duration was not associated with aggressive prostate cancer.
Key Findings
Results
Shorter sleep duration (<6 hours) was suggestively associated with decreased prostate cancer risk in the overall cohort compared to optimal sleep duration (7-8 hours).
Adjusted HR for weighted average sleep duration <6 h vs. 7-8 h: 0.83 (95% CI: 0.68–1.01)
The association for average sleep duration did not reach conventional statistical significance (CI crossed 1.0), while weekday and weekend measures did
Cox proportional hazards models were used to estimate associations
Results
Among Black (Non-Hispanic Black) men specifically, shorter sleep duration (<6 hours) was associated with a statistically significant decreased risk of prostate cancer.
HR for average sleep <6 h among Black men: 0.77 (95% CI: 0.62–0.97)
HR for weekday sleep <6 h among Black men: 0.76 (95% CI: 0.61–0.94)
HR for weekend sleep <6 h among Black men: 0.74 (95% CI: 0.59–0.94)
All three sleep duration measures showed statistically significant associations (CIs did not cross 1.0) in Black men
The cohort was approximately 67% African American
Results
Sleep duration and restless sleep were not associated with prostate cancer aggressiveness in the overall cohort.
Multinomial logistic regression models were used to assess associations with prostate cancer aggressiveness
No statistically significant associations were found between any sleep exposure measure and aggressive prostate cancer
Sleep exposures assessed included weekday sleep duration, weekend sleep duration, weighted average sleep duration, and restless sleep
Methods
During the study follow-up period, 1,345 men developed prostate cancer out of nearly 35,000 male participants.
The Southern Community Cohort Study (SCCS) recruited participants from 12 Southeastern states between 2002 and 2009
Median follow-up was 10.9 years
The cohort was predominantly African American (67%)
Sleep exposures were measured via a baseline questionnaire at enrollment capturing weekday, weekend, and weighted average sleep duration, as well as restless sleep
Results
The association between shorter sleep duration and decreased prostate cancer risk was not observed among White men in race-stratified analyses.
Stratified analyses by racial groups revealed that the inverse association between short sleep (<6 h) and prostate cancer risk was specific to Black men
Authors noted this is an 'intriguing finding' and called for further research to assess confounding factors on racial differences in prostate cancer development
White men did not show statistically significant associations between sleep duration and prostate cancer risk in stratified analyses
What This Means
This research suggests that men who sleep fewer than 6 hours per night may have a lower likelihood of developing prostate cancer compared to men who sleep the recommended 7–8 hours, based on data from nearly 35,000 men followed for about 11 years across 12 Southeastern U.S. states. However, this finding was most consistent and statistically clear among Black men in the study — those sleeping less than 6 hours showed roughly a 23–26% lower prostate cancer risk compared to Black men sleeping 7–8 hours. The same pattern was not clearly seen among White men.
Importantly, the amount or restlessness of sleep did not appear to be linked to whether prostate cancers were more or less aggressive. This means that even if shorter sleep relates to who gets diagnosed, it does not seem to change how serious the cancer is once it develops.
This research suggests that the relationship between sleep and prostate cancer may differ by race, which is a notable and somewhat unexpected finding. However, the authors caution that this could be influenced by other unmeasured factors, and they call for additional studies to better understand why this racial difference exists and whether sleep truly plays a causal role. The counterintuitive direction of the finding — that less sleep appears linked to lower risk — makes careful interpretation and further investigation especially important.
Anukam D, Nianogo R, Arah O, Boutros P, Rao J, Fowke J, et al.. (2026). Sleep Duration and Prostate Cancer Risk in the Southern Community Cohort Study.. Cancer medicine. https://doi.org/10.1002/cam4.71466