Published: December 8, 2016

    Does Your Body Tell You How Much Water You Should Drink?

    How much water should you drink every day? The old colloquial standard is eight glasses of water per day (roughly 64 ounces), but as most people very widely in size, body weight, and body mass index, this is far from an exact number. Dehydration causes several unwanted health problems, like constipation and high blood pressure. It’s obviously important to stay hydrated throughout the day, but how do you know when enough is enough?

    A new study conducted by Michael Farrell (Monash University, Melbourne, Australia) has determined that the human body plays a much more active part in regulating our fluid intake than previously believed. According to Farrell and his team, the body demonstrates “swallowing inhibition” shortly after a large intake of water, limiting our chances of becoming overhydrated.

    In the abstract of the study Farrell describes his team’s methodology: using functional magnetic resonance imaging (fMRI) to measure regional responses in the brain when participants attempted to swallow small volumes of water. The measurements were taken when participants were adequately thirsty and when they had just consumed a large amount of water.

    When participants had “overdrank” prior to swallowing the water, the amount of effort needed to swallow the water increased threefold. Repeatedly, it was more difficult for participants to swallow water when they were properly (or over) hydrated. This brain activity supports the notion of an involuntary swallowing inhibition in the brain that regulates water levels in the body.

    The scientists measured brain waves in several regions of the brain, including the prefrontal cortex, the motor cortex, the brainstem, and the posterior parietal cortex in order to reach their conclusions. The evidence overwhelming supports the theory that your mind works with your body to make it harder to swallow when you’ve had enough to drink.

    So if you’re body seems clued in on your optimal water levels, should you stick to that recommended eight glasses of water a day? According to Farrell, only if your body is in sync with that decision. His study, he claims, is evidence that the average person should not deliberately try to consume fluids if they do not feel thirsty.

    As far as Farrell is concerned, the body is the ultimate measuring tool. His study seems to confirm these beliefs. “It shows we have several very subtle mechanisms for regulating the amount we drink,” he stated. “If left to your own devices, you will drink the requisite amount of water to maintain balance.”

    Farrell also advises that this trust in your body should extend to periods of physical exertion. According to Farrell those who are exercising should still rely on thirst instead of drinking fluids simply because they’re active. “These are well refined mechanisms forged on the anvil of evolution,” he said.

    So maybe the “eight glasses a day” rule is open to some interpretation. But regardless of how much you drink, you should always fuel your body with cleaner, purer filtered water. Invest in a whole house filter to provide your family with refreshing water free of contaminants. Stay hydrated and happy with reliable filtered water.