Research Results

A population-based case-control study in Spain (2008-2013) including 621 prostate cancer cases, 1,205 breast cancer cases, and 2,193 controls who never worked night shifts examined whether meal timing is associated with cancer risk while accounting for lifestyle factors and chronotype (morning vs. evening preference). Participants who waited two or more hours between supper and sleep had a 20% reduced risk of breast and prostate cancer combined (OR = 0.80; 95% CI: 0.67-0.96) compared to those sleeping immediately after eating, with individual reductions of 26% for prostate cancer and 16% for breast cancer; similarly, eating supper before 9 pm versus after 10 pm showed protective effects, with stronger associations among those adhering to cancer prevention recommendations (OR = 0.65) and morning chronotypes (OR = 0.66). These findings suggest that adhering to diurnal eating patterns—particularly maintaining a long interval between the last meal and sleep—is associated with lower breast and prostate cancer risk, independent of diet quality and other lifestyle factors. The study highlights the emerging importance of meal timing and circadian rhythm alignment in cancer prevention, indicating that when we eat may be as important as what we eat, and suggesting that late-night eating close to bedtime may disrupt metabolic and hormonal processes that influence cancer development.