Good hydration key to living longer, healthier life : Study

WASHINGTON DC: Scientists have found good levels of hydration may be key to living a longer and healthier life.

According to the National Institutes of Health (NIH) study, adults who stay well-hydrated appear to be healthier, develop fewer chronic conditions, such as heart and lung disease, and live longer than those who may not get sufficient fluids.

Using health data gathered from 11,255 adults over a 30-year period, researchers analyzed links between serum sodium levels - which go up when fluid intake goes down - and various indicators of health.

The researchers found that adults with serum sodium levels at the higher end of a normal range were more likely to develop chronic conditions and show signs of advanced biological aging than those with serum sodium levels in the medium ranges. Adults with higher levels were also more likely to die at a younger age.

The findings are published in the journal eBioMedicine.

''The results suggest that proper hydration may slow down aging and prolong a disease-free life,'' said Natalia Dmitrieva, a study author and researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute (NHLBI), part of NIH.

For the analysis, researchers assessed information study participants shared during five medical visits – the first two when they were in their 50s, and the last when they were between ages 70-90, the study said.

To allow for a fair comparison between how hydration correlated with health outcomes, researchers excluded adults who had high levels of serum sodium at baseline check-ins or with underlying conditions, like obesity, that could affect serum sodium levels, the study said.

The scientists then evaluated how serum sodium levels correlated with biological aging, which was assessed through 15 health markers. This included factors, such as systolic blood pressure, cholesterol, and blood sugar, which provided insight about how well each person's cardiovascular, respiratory, metabolic, renal, and immune system was functioning. They also adjusted for factors, like age, race, biological sex, smoking status, and hypertension, the study said.

They found that adults with higher levels of normal serum sodium - with normal ranges falling between 135-146 milliequivalents per liter (mEq/L) - were more likely to show signs of faster biological aging. This was based on indictors like metabolic and cardiovascular health, lung function, and inflammation.

For example, adults with serum sodium levels above 142 mEq/L had a 10-15 per cent associated increased odds of being biologically older than their chronological age compared to ranges between 137-142 mEq/L, while levels above 144 mEq/L correlated with a 50 per cent increase.

Likewise, levels of 144.5-146 mEq/L were associated with a 21 per cent increased risk of premature death compared to ranges between 137-142 mEq/L, the study said.

Similarly, adults with serum sodium levels above 142 mEq/L had up to a 64 per cent increased associated risk for developing chronic diseases like heart failure, stroke, atrial fibrillation and peripheral artery disease, as well as chronic lung disease, diabetes, and dementia.

Conversely, adults with serum sodium levels between 138-140 mEq/L had the lowest risk of developing chronic disease, the study said.

The findings do not prove a causal effect, the researchers noted. Randomized, controlled trials are necessary to determine if optimal hydration can promote healthy aging, prevent disease, and lead to a longer life. However, the associations can still inform clinical practice and guide personal health behaviour.

''The goal of providing medical guidance is to ensure patients are taking in enough fluids, while assessing factors, like medications, that may lead to fluid loss,'' said Manfred Boehm, a study author and 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,'' said Boehm.