Insomnia is becoming increasingly common, affecting sleep quality and overall well-being. While melatonin and sleep-supporting functional foods are widely used, potassium may also play a role in healthy sleep. A recent Japanese study of 4,568 adults found that higher daily potassium intake was associated with lower insomnia scores, with potassium intake at dinner showing the strongest association. As an essential electrolyte, potassium supports nerve signaling, muscle function, and blood pressure regulation, suggesting potential links between adequate potassium intake and better sleep. Potassium can be obtained from foods such as mushrooms, legumes, potatoes, fruits, vegetables, and milk, while potassium supplements may be considered when dietary intake is insufficient.
Insomnia is becoming an increasingly widespread problem. Insomnia, frequent dreaming, and poor sleep quality have become major health concerns affecting consumers.
People struggling with sleep problems often turn to melatonin or functional foods with sleep-supporting properties. Yet few people pay attention to the low-profile macromineral potassium, which may be an important factor in supporting healthy sleep.
In recent years, a research article from a Japanese research team, The Association of Sodium or Potassium Intake Timing with Athens Insomnia Scale Scores: A Cross-Sectional Study, reported that potassium intake was significantly associated with improved insomnia status.
Higher Potassium Intake at Dinner May Be Associated with Better Sleep
The research team used Asken, a widely used dietary-recording mobile application in Japan, to collect data on sodium and potassium intake among 4,568 adult users at breakfast, lunch, dinner, and snack times. The severity of sleep disturbances was quantified using the Athens Insomnia Scale (AIS). The assessment revealed the following findings:
1) Higher Total Potassium Intake Was Associated with Fewer Insomnia Symptoms
Based on AIS scores, the researchers divided participants into three groups: normal sleep, subclinical insomnia, and clinical insomnia.
Statistical analysis of the average daily potassium intake in these three groups showed that total daily potassium intake was significantly negatively correlated with the logarithmically transformed AIS score. In other words, higher total potassium intake was associated with less severe insomnia symptoms.
2) Potassium Intake at Dinner Showed the Strongest Association with Sleep
However, potassium intake at breakfast, lunch, and snack times did not show significant associations with insomnia scores. In contrast, potassium intake at dinner was independently and significantly negatively associated with AIS scores.
Moreover, the absolute value of the standardized regression coefficient for potassium intake at dinner was greater than that for total daily potassium intake. This suggests that, when considering the potential relationship between potassium intake and sleep, when potassium is consumed may be more relevant than simply how much potassium is consumed in total.
Exploring the Potential Mechanisms Behind Potassium and Sleep
Potassium (chemical symbol K) is an essential macromineral and one of the body's most important electrolytes. It contributes to maintaining cellular osmotic balance, nerve signal transmission, muscle contraction, and heart rhythm, and therefore performs multiple important physiological functions in the human body.
Further research by Japanese scientists has explored how potassium may be related to sleep through its effects on several physiological processes.
1) Relieving Muscle Tension and Reducing Sleep Disturbances
As a key element involved in neuromuscular signal transmission, adequate potassium intake helps maintain normal muscle contraction and relaxation. This may help the body transition more smoothly from a state of daytime tension to nighttime relaxation, potentially reducing sleep disturbances associated with nighttime muscle cramps and muscle tension.
2) Regulating Neuronal Excitability and Supporting Deep Sleep
At the central nervous system level, potassium ion channels in the brain are important components in regulating neuronal excitability. They are directly involved in the transition between sleep and wakefulness as well as the generation of slow-wave activity, which forms the physiological basis of the restorative functions of deep sleep.
3) Regulating Nighttime Blood Pressure and Supporting Sleep Quality
Previous meta-analysis research has demonstrated that abnormal nighttime blood pressure patterns, including non-dipping patterns, are closely associated with sleep quality.
Potassium may exert blood-pressure-lowering effects through several pathways, including promoting sodium excretion, improving vascular endothelial function, and regulating baroreceptor sensitivity. Consuming potassium at dinner may coincide with a key period for nighttime blood pressure regulation, thereby potentially supporting sleep indirectly.
From a mechanistic perspective, the potential pathways through which potassium may influence blood pressure and sleep overlap to a considerable extent. This also suggests that a potassium-rich diet may provide potential benefits for both sleep and blood pressure regulation: when blood pressure becomes more stable and normal nighttime blood pressure rhythms are maintained, sleep quality may also improve. These two physiological processes may influence each other and potentially form a positive cycle.
Inadequate Potassium Intake Highlights the Importance of Daily Intake
Although everyday foods such as bananas, oranges, spinach, and broccoli are rich sources of potassium, some populations may still fail to reach recommended potassium intake levels and therefore need to increase potassium consumption through their daily diet.
In addition, inadequate dietary potassium intake and an imbalance between sodium and potassium are important modifiable risk factors associated with cardiovascular disease, which remains the leading cause of death globally. Adequate potassium intake may help regulate blood pressure and support cardiovascular health.
Given the important role of adequate potassium intake in overall health, how can potassium be obtained scientifically in daily life?
Dietary Sources of Potassium
Mushrooms such as shiitake mushrooms, fresh legumes such as edamame, tubers such as potatoes, and dried legumes such as soybeans and kidney beans are all notable dietary sources of potassium.
Milk is also a good dietary source of potassium. One 250 mL cup of milk can provide approximately 275 mg of potassium.
Potassium Supplements and Functional Foods
If dietary intake remains insufficient, additional potassium supplementation may be considered. There are various types of potassium supplements currently available on the market. Common forms include potassium citrate, potassium gluconate, potassium aspartate, potassium chloride, and potassium lactate.
Potassium citrate: Also known as potassium citras, potassium citrate is one of the most commonly used potassium supplements. In addition to providing potassium ions, it can alkalinize urine and may help support the prevention of kidney stones.
Potassium aspartate: Aspartic acid is an amino acid involved in energy metabolism in the human body. Potassium aspartate may help promote the entry of potassium ions into cells and is commonly used to support myocardial energy metabolism and help relieve fatigue.
Conclusion
Sleep is a complex physiological process influenced by multiple factors, including nutrition, lifestyle, neurological regulation, and cardiovascular function. The findings from the Japanese cross-sectional study provide an interesting perspective on the potential relationship between potassium intake and insomnia, particularly the timing of potassium intake at dinner.
At the same time, these findings should be interpreted with appropriate scientific caution. The study was cross-sectional in design, meaning that an association between potassium intake and insomnia scores does not by itself establish a causal relationship. Nevertheless, potassium remains an essential nutrient with important physiological functions, and maintaining adequate dietary potassium intake is an important part of a balanced diet and overall health.
For consumers seeking to support sleep and cardiovascular health, potassium-rich foods can be incorporated into a balanced daily diet. When supplementation is considered, the appropriate potassium form and intake level should be selected according to individual nutritional needs and health circumstances.
References
[1] Okamoto T, Lo YP, Khaing IK, et al. The Association of Sodium or Potassium Intake Timing with Athens Insomnia Scale Scores: A Cross-Sectional Study. Nutrients. 2025, 17(1): 148.
[2] Aburto NJ, Hanson S, Gutierrez H, et al. Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses. BMJ. 2013, 346: f1378.