Drink up to slow down early aging and chronic disease, a new study suggests.

In results posted Monday from the National Institutes of Health, adults who aren't hydrated sufficiently might age faster, face a higher risk of chronic diseases, and be more likely to die younger than those who remain well-hydrated.

Researchers looked at levels of sodium in the participants' blood as a proxy for hydration — since higher concentrations are a sign they most likely weren't consuming enough fluids, according to NBC News, which reported the research.

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 researchers found.

Those in the study all had blood-sodium concentrations considered to be within the normal range. However, the findings suggested those with levels at the higher end of the normal range were 50% more likely to show signs of physical aging beyond what would be expected for their years compared with people with lower blood-sodium levels, the news outlet reported of the findings.

They also had a roughly 20% increased risk of premature death.

Even participants with blood-sodium levels that weren’t quite at the high end 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, told NBC News.

Just like regular physical activity and proper nutrition being part of a healthy lifestyle, "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,” she told the news outlet.

Not everyone is convinced, the news outlet noted.

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

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

Appel argued people would probably need much higher blood-sodium levels to see negative health outcomes — and factors beside hydration can influence someone’s blood-sodium level.

For example, Dr. Mitchell Rosner, chair of the University of Virginia Department of Medicine, told NBC News that some people with neurological issues or other disabilities may also have higher-than-average blood-sodium levels.

And Asher Rosinger, director of the Water, Health and Nutrition Lab at Penn State College of Health and Human Development, told the news outlet it’s more likely chronic dehydration speeds the aging process than that good hydration could help slow it down.

Proper hydration "will ensure kidneys work properly and extra stress isn't placed on the body physiologically," he told NBC News.

The National Academies of Medicine recommends six to nine 8-ounce cups of fluid per day for women, and eight to 12 for men. But the traditional recommendation is "really not based on any scientific evidence,” Appel told the outlet.

"Dehydration in the general population is just not a common issue," he added.

• Most Americans Don't Drink Enough Water
• Beyond Water: The Most Hydrating Foods and Drinks