While most people are aware of the standard recommendation to drink eight glasses of water per day, new research from the National Institute of Health suggests that adequate hydration can help to prevent chronic illness and extend one’s lifespan.
Researchers monitored 11,000 U.S. adults aged 45-66, who returned 25 years later for follow-up tests, and found that those with high blood-sodium levels in middle age — indicating insufficient fluid intake — had aged physically at an accelerated rate. As a result, they displayed a marked increase in health measures associated with aging, including blood pressure, cholesterol and blood sugar.
Those with a blood-sodium measure at the higher end of the normal range (above 142 millimoles per liter) were likely to be physiologically older, and exhibited a 39% higher risk of developing chronic diseases. Meanwhile, those with a measure exceeding 144 millimoles per liter experienced a 21% higher risk of mortality. The study, published in eBioMedicine in on January 2, 2023, built on earlier research in which scientists linked higher blood sodium levels with a greater risk of heart failure.
“The results suggest that proper hydration may slow down aging and prolong a disease-free life,” said study author and NIH researcher Natalia Dmitrieva in a press release. “On the global level, this can have a big impact.”
More Research Needed — but Hydration Can’t Hurt
Dr. Lawrence Appel, director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins University, told NBC that the study “doesn’t prove that drinking more water will prevent chronic disease.” Appel suggested that much more extreme rates of hydration would be necessary to produce negative health outcomes, and noted that diuretic medications and other factors could impact blood sodium levels.
Regardless, hydration has been shown to benefit short-term and long-term health in numerous ways, including regulating body temperature, preventing infections and improving sleep quality.
So, how much water is enough?
While eight glasses a day is a reasonable standard, according to the Mayo Clinic, individuals may need more or less depending on their physiology, environment, rate of exercise and overall health (not to mention, herbal teas, fruits, and other foods and beverages can also boost water intake). If you’re rarely thirsty, and your urine is clear or light yellow in color, you’re likely hydrated enough.