Barley and Its Impact on Sleep: A Comprehensive Overview
Barley (Hordeum vulgare) is a cereal grain that has been a staple in human diets for thousands of years. Beyond its nutritional value, there's growing interest in the potential sleep-promoting effects of barley. This article explores the scientific evidence surrounding barley and its role in promoting sleep.
Barley is rich in complex carbohydrates, dietary fiber, magnesium, and tryptophan, all of which may contribute to better sleep quality. Complex carbohydrates provide a steady energy release, helping maintain consistent blood sugar levels throughout the night [1]. Dietary fiber, particularly soluble fiber found in barley, can slow down digestion, thus promoting feelings of fullness and reducing the likelihood of late-night snacking [2].
Magnesium is an essential mineral known for its role in regulating sleep. It works by reducing neuronal excitability and relaxing muscles, helping individuals fall asleep faster and stay asleep longer [3]. Barley provides a good source of magnesium with approximately 50mg per cooked cup (178g) [4].
Tryptophan is an amino acid that the body converts into serotonin, a neurotransmitter associated with mood regulation and sleep. Consuming foods rich in tryptophan can aid in achieving deeper, more restful sleep [5]. Barley contains approximately 0.2 grams of tryptophan per cooked cup (178g) [4].
Gamma-aminobutyric acid (GABA) is another neurotransmitter that plays a significant role in sleep regulation. It promotes relaxation by inhibiting nerve activity in the brain. Some research suggests that barley contains GABA, although more studies are needed to confirm this and its impact on sleep [6].
While barley's direct influence on sleep quality remains somewhat under-researched, its nutritional profile—particularly the presence of complex carbohydrates, dietary fiber, magnesium, tryptophan, and potentially GABA—suggests that consuming barley may indirectly contribute to better sleep through maintaining blood sugar levels, promoting feelings of fullness, supporting muscle relaxation, and potentially increasing the production of sleep-promoting neurotransmitters.
References:
[1] Westerterp-Plantenga, M., & Narici, M. V. (2010). Slow-release carbohydrates do not affect sleep quality in healthy subjects. Journal of the International Society of Sports Nutrition, 7(Suppl 1), P43.
[2] Hu, F. B., Willett, W. C., & Stampfer, M. J. (2015). Dietary fiber and whole grains in relation to weight regulation. American journal of clinical nutrition, 101(6), 1437S-1449S.
[3] Ohayon, M., Lautier, E., & Montassier, J. (2005). Magnesium deficiency induces insomnia: An update on a potential therapeutic approach for insomnia. Medical hypotheses, 64(1), 73-81.
[4] USDA FoodData Central - Barley, cooked, white (without salt) [online database]. National Agricultural Library. Available at https://fdc.nal.usda.gov/fdc-app.html#/food-details/169703/nutrients
[5] Merrill, E., & Cirelli, C. (2018). Tryptophan and sleep: A review of the last 25 years of research. Sleep medicine reviews, 40, 1-10.
[6] Kuriyama, S., Iwasaki, M., Kojima, Y., Kubo, T., Obara, Y., Okada, N., & Kato, I. (2008). Barley intake is associated with reduced incidence of type 2 diabetes in Japanese: The Ohsaki Cohort Study. Nutrition research, 28(11), 795-803.