Drink up: Large study finds that not consuming enough water increases risk of death by 20%

Drink less, age more.

That’s the key takeaway from a study published Monday in the medical journal the Lancet. It found that adults who aren’t hydrated enough may age faster and even have a higher risk for chronic diseases that could result in early death.

Researchers from the National Institutes of Health conducted the study over a 25-year period, analyzing the medical visits of more than 11,000 adults in the US from ages 45 to 66 and then their follow-up visits at ages 70 through 90. 

“Emerging evidence from our and other studies indicate[s] that adding consistent good hydration to [other] healthy lifestyle choices may slow down the aging process,” the study’s lead author, Natalia Dmitrieva, said in an email to NBC news.

During the study, researchers tracked hydration in subjects by monitoring how much sodium was found in their blood – the higher the sodium levels, the less hydrated participants are.

The analysis showed that all 11,000 participants’ hydration was within a normal range, with blood-sodium concentrations between 135 to 146 millimoles per liter. However, those individuals with levels on the higher end of that range — greater than 144 millimoles per liter — were 50% more likely to show signs of physiological aging. Those includes high cholesterol, blood pressure and surging sugar levels along with physical signs such as sunken eyes, cheeks and dry skin.

“People whose middle-age serum sodium exceeds 142 mmol/l have increased risk to be biologically older,” researchers wrote in the study.

Most shockingly, that cohort also had a near 20% increase in the risk of premature death, the study suggested. They showed a greater likelihood for developing fatal diseases such as heart failure, stroke, diabetes, dementia and chronic lung diseases.

“Risk to develop these diseases increases as we age and accumulate damages in various tissues in the body,” Dmitrieva, a researcher at the National Institutes of Health’s Heart, Lung and Blood Institute, told NBC.

In previous research, Dmitrieva has found that dehydration can lead to an increased risk for heart failure.

The USDA recommends drinking eight to 10 glasses of water per day, but a 2020 study of 2,000 US adults found that just 20% of people are meeting that goal. As people age, the thirst response weakens, making them less likely to realize they need more water.