Poor hydration may be linked to early aging and chronic disease, a 25-year study finds

Adults who aren’t sufficiently hydrated may age faster, face a higher risk of chronic diseases and be more likely to die younger than those who stay well-hydrated, according to a new study from the National Institutes of Health.

The results, published Monday, are based on data collected over 25 years from more than 11,000 adults in the U.S. The participants attended their first medical visits at ages 45 to 66, then returned for follow-ups through at ages 70 to 90.

The researchers looked at levels of sodium in the participants’ blood as a proxy for hydration, because higher concentrations are a sign that they most likely weren’t consuming enough fluids. The researchers found that the participants with high blood-sodium levels aged faster physiologically than those with lower levels, which was reflected in health markers associated with aging, like high blood pressure, cholesterol and blood sugar.

The study participants all had blood-sodium concentrations considered to be within the normal range: 135 to 146 millimoles per liter. But the findings suggested that people with levels at the higher end of that normal range — above 144 millimoles per liter — were 50% more likely to show signs of physical aging beyond what would be expected for their years compared to people with lower blood-sodium levels. They also had a roughly 20% increased risk of premature death.

Even people with blood-sodium levels above 142 millimoles per liter had elevated risks of developing certain chronic diseases, including heart failure, stroke, chronic lung disease, diabetes and dementia, the study found.

“Risk to develop these diseases increases as we age and accumulate damages in various tissues in the body,” one of the study’s authors, Natalia Dmitrieva, a researcher at the NIH’s National Heart, Lung, and Blood Institute, said in an email.

Dmitrieva’s previous research similarly found that higher blood sodium may be a risk factor for heart failure.

Just as regular physical activity and proper nutrition are considered part of a healthy lifestyle, she said, “emerging evidence from our and other studies indicate that adding consistent good hydration to these healthy lifestyle choices may slow down the aging process even more.”

But the study authors cautioned that more research is needed to determine whether good hydration can help slow aging, prevent disease or lead to a longer life.

The relationship between drinking fluids and age-related chronic diseases remains “highly speculative,” said Dr. Lawrence Appel, the director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins University.

The NIH study “doesn’t prove that drinking more water will prevent chronic disease,” he said.