Nutritional intervention rich in tryptophan enhances sleep duration and reduces wakefulness during breast cancer treatment

Background: Sleep disorders are highly prevalent among women undergoing treatment for breast cancer, often exacerbated by the side effects of chemotherapy. Nutritional strategies using foods rich in tryptophan and precursors of melatonin may help regulate sleep, but evidence in cancer populations remains limited.Objective: To evaluate the effect of a tryptophan-rich dietary intervention on sleep parameters in women undergoing chemotherapy for breast cancer.Methods: Fifty women were randomized into a Sleep Diet Group (SDG) that received a tryptophan-rich meal plan (>3000 mg/day) or a Control Group (CG) that received a diet without specific foods to facilitate sleep. Sleep was monitored daily for six weeks using actigraphy (Mi Band 4C®), assessing total sleep time (TST), light sleep, deep sleep and wake after sleep onset (WASO). Fatigue and insomnia severity were assessed before and after the intervention.Results: The SDG had significantly higher TST compared to the CG in weeks 4 and 5 (p = 0.007 and p = 0.010, respectively). WASO was significantly lower in the SDG during weeks 2 and 4 (p = 0.011 and p = 0.035). No significant differences in deep sleep were observed between groups (p = 0.214). Both groups showed subjective improvements in insomnia severity, with no differences between groups. Fatigue scores remained unchanged.Conclusion: A dietary intervention with tryptophan-rich foods improved total sleep time and reduced nighttime awakenings in women undergoing breast cancer treatment. These findings suggest that targeted nutritional strategies may support sleep regulation during chemotherapy.