Bangkok: Concerns about the timing of water consumption affecting kidney health have been addressed by Dr. Bongkot Suratchaikul, a nephrologist at Bhumibol Adulyadej Hospital’s Kidney Institute.
According to Thai News Agency, Dr. Suratchaikul clarified that there is no evidence suggesting that drinking plain or cold water before or between meals has any negative impact on kidney function. While some studies have indicated that consuming cold water might stimulate the vagus nerve, potentially slowing the heart rate slightly, there is no direct effect on the kidneys.
The vagus nerve, the tenth cranial nerve, plays a crucial role in connecting the brain with various organs and controlling involuntary functions like digestion and heart rate. Some research suggests that drinking water before meals may dilute digestive juices but can aid in weight control by promoting a sense of fullness. Additionally, consuming water before bed may prevent dehydration and reduce the risk of kidney stones for susceptible individuals, though excessive intake might lead to frequent urination at night.
Dr. Suratchaikul emphasized that there are no reports linking specific timing of water consumption to adverse kidney effects, such as kidney pressure, chronic nephritis, or acute renal failure. The body’s circadian rhythm, a 24-hour cycle influenced by internal and external factors, affects organ functions, including the kidneys. The production of ADH (Antidiuretic Hormone), which helps retain water in the body, increases at night to prevent dehydration during sleep. Drinking an appropriate amount of water before bed can support this natural process.
The daily water intake requirement varies based on individual factors such as age, climate, physical activity, and health conditions. While the general recommendation is to consume at least 8 glasses of water per day, adjustments should be made according to personal needs and lifestyle. Monitoring urine color can be a useful indicator of hydration levels. For individuals with reduced renal function, especially those with end-stage renal disease, careful management of water intake is necessary, with emphasis on spreading consumption throughout the day rather than ingesting large quantities at once.