BETHESDA, Md. — Drinking more water each day could be the secret to aging slower and living longer. A new study has found that people who stay hydrated suffer from fewer chronic illnesses and have longer lifespans than those who don’t get enough fluids.
The findings come from a 30-year review of 11,255 adults, who had their serum sodium levels measured at various points over that period. Serum sodium goes up when a person’s fluid intake goes down. Simply put, if you’re dehydrated, your serum sodium levels increase.
The team from the National Heart, Lung, and Blood Institute found that serum sodium levels at the higher end of the normal range for people showed signs of accelerated biological aging. They were also more likely develop chronic conditions such as heart and lung disease. Additionally, these individuals were more likely to die at younger ages.
“The results suggest that proper hydration may slow down aging and prolong a disease-free life,” says study author Natalia Dmitrieva, Ph.D., a researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute (NHLBI), in a media release.
When does serum sodium reach a danger point?
Researchers say elevated levels fall between 135 and 146 milliequivalents per liter (mEq/L). People in this higher-but-still-normal range displayed signs of aging faster than those with lower serum sodium levels and those who regularly drank more water.
For participants with a serum sodium level above 142 mEq/L, they had a 10 to 15-percent higher chance of being biologically older than their chronological age (their actual birthdate) than those with levels between 137 and 142 mEq/L. Those who had a serum sodium level above 144 mEq/L had a 50-percent chance of aging faster.
Concerningly, participants with serum sodium levels between 144.5 and 146 mEq/L had a 21-percent higher risk of premature death. For anyone above 142 mEq/L, there was a 64-percent higher risk of developing heart disease, suffering a stroke, or having atrial fibrillation and peripheral artery disease. These individuals also had a higher risk of developing chronic lung disease, diabetes, and dementia.
Study authors arrived at these findings after assessing five medical visits by each participant. The first two took place when each person was in their 50s. The last took place between the ages of 70 and 90. The team excluded individuals with abnormally high serum sodium levels and those with underlying health conditions, such as obesity. From there, they compared serum sodium levels to 15 markers of biological aging — including systolic blood pressure, cholesterol, and blood sugar.
How many glasses of water do you need?
Although researchers say their results can’t prove there’s a causal link between hydration and aging, the study still provides good insight that can help people live healthier.
“People whose serum sodium is 142 mEq/L or higher would benefit from evaluation of their fluid intake,” Dmitrieva says.
The study authors add that fluids include water, juices, and hydration coming from vegetables and fruits with a high water content. Moreover, the National Academies of Medicine recommends that women consume between six and nine cups of fluid per day (1.5-2.2 liters). For men, the number is eight to 12 cups (2-3 liters).
“The goal is to ensure patients are taking in enough fluids, while assessing factors, like medications, that may lead to fluid loss,” says Manfred Boehm, M.D., the director of the Laboratory of Cardiovascular Regenerative Medicine. “Doctors may also need to defer to a patient’s current treatment plan, such as limiting fluid intake for heart failure.”
Researchers note that half of the world’s population doesn’t stay properly hydrated.
“On the global level, this can have a big impact,” Dmitrieva concludes. “Decreased body water content is the most common factor that increases serum sodium, which is why the results suggest that staying well hydrated may slow down the aging process and prevent or delay chronic disease.”
The study is published in the journal eBioMedicine.