Kang Lai, Class of 2026

Sleep is an important controlling factor of many regulatory and restorative functions of the human body. However, many conditions have impacted sleep quality, the most prevalent being insomnia. A study conducted by Dr. Muteber Gizen Keser and colleagues at KTO Karatay University examined certain biochemical parameters and behavioral analyses to determine whether banana and milk lead to the improved sleep quality in insomnia patients. These researchers aimed to determine the effects of banana and milk on sleep quality and levels of Brain Derived Neurotrophic Factor (BDNF), leptin, and ghrelin in patients with insomnia over six weeks. BDNF and ghrelin, two good indicators of food intake and body weight, are factors that ultimately affect sleep quality. Similarly, leptin concentration in the body fluctuates with sleep deprivation. 

21 patients diagnosed with insomnia by the American Sleep Medicine Academy were randomized into either a banana group, milk group, or a control group. Based on the group assignment, participants were instructed to consume 85-100g of banana, 200ml of milk, or neither at bedtime. Venous blood samples were taken to analyze serum BDNF, leptin and ghrelin concentrations. The Pittsburgh Sleep Quality Index (PSQI) was then used as a subjective sleep assessment method. After 6 weeks of intervention, the PSQI score of the milk and banana group was significantly lower than that of the control group, suggesting that milk and banana led to improved sleep quality. Only the milk group affected sleep time significantly. All groups showed an overall change, but no significant difference in total sleep time or sleep efficiency was measured. While there was overall change in BDNF and leptin concentrations, ANOVA tests revealed these changes were insignificant in regards to baseline and post intervention concentrations. 

Bananas and milk are rich in tryptophan, an amino acid involved in the release of insulin. Due to the sugar in bananas and milk, the release of insulin may be promoted–allowing larger amino acids into muscle tissue and tryptophan to cross the blood brain barrier. This signals the synthesis of serotonin and melatonin, key hormones that improve sleep quality. In addition, a significant decrease in ghrelin concentrations in the milk group may imply an indirect influence on better sleep quality by positively regulating one’s diet. This study provides promising information regarding the role of certain foods in affecting sleep disorders. Future directions may include the study of differing diets and their effects on the aforementioned biomolecules, in hopes to attain a better understanding of sleep quality and disorders.

Figure 1: A banana next to a glass of milk.

Works Cited:

[1] Keser, M. G., Yuksel, A., Ekmekci, A. H., & Vatansev, H. (2024). Bedtime banana and milk intake on sleep and biochemical parameters. Asia Pacific journal of clinical nutrition, 33(4), 481–489. https://doi.org/10.6133/apjcn.202412_33(4).0002

[2] Image retrieved from: https://commons.m.wikimedia.org/wiki/File:Bananamilk_1.jpg