Drinking eight glasses of water a day has almost become common knowledge, and many people believe that drinking more water can help with weight loss. But is drinking so much water really good for us? A study shows that drinking too much water activates a mechanism in the brain that suppresses swallowing. Once this suppression mechanism is exceeded, we risk water intoxication, which is medically known as "hyponatremia." Hyponatremia is a condition caused by an excess of water in the body, leading to low sodium levels in the blood. It can symptoms such as drowsiness, nausea, seizures, and even coma, and if not treated promptly, it can lead to death within a few hours.
Feeling thirsty is a healthier way to know when to drink water
Dr. Michael Farrell, the lead researcher from Monash University in Melbourne, said, "The correct way to drink water is according to your body's needs. Feeling thirsty and then drinking is healthier than following a precise drinking schedule. We found that after drinking excessive amounts of water, swallowing becomes more effortful, meaning we have to overcome a certain resistance. Marathon athletes have died in certain situations from drinking too much water because they blindly followed the advice to drink large quantities, ultimately consuming far more than their bodies needed."
Functional magnetic resonance imaging (fMRI) was used to measure the activity of different parts of the brain, primarily reflecting the brain's immediate reaction before a person swallows. Researchers had participants drink water in two scenarios after exercise: one when they were very thirsty, and the other when they were asked to drink excessive amounts of water. The results showed that the brain's swallowing mechanism's workload increased threefold after over-hydration. However, the scans showed that when participants drank excessive water, the prefrontal cortex of the brain was more active than usual. Researchers believe that people can only drink water when the prefrontal cortex intervenes to overcome the swallowing mechanism. Dr. Farrell noted that it's important to be aware that older people often do not consume enough water and should be monitored for their fluid intake.
If water enters the body faster than it is expelled, the electrolytes in the blood become diluted. This allows water to move from the blood into cells and organs like the brain, thereby affecting their function.