New findings suggest that proper hydration could be the key to slowing down ageing and prolonging a healthy life.
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, according to a National Institutes of Health study.
Using health data gathered from 11,255 adults over a 30-year period, researchers analysed links between serum sodium levels – which go up when fluid intake goes down – and various indicators of health.
They 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 ageing 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 study expands on research the scientists published in March 2022, which found links between higher ranges of normal serum sodium levels and increased risks for heart failure.
Both findings came from the Atherosclerosis Risk in Communities (ARIC) study, which includes sub-studies involving thousands of Black and white adults from throughout the United States. The first ARIC sub-study started in 1987 and has helped researchers better understand risk factors for heart disease, while shaping clinical guidelines for its treatment and prevention.
For this latest 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.
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.
They then evaluated how serum sodium levels correlated with biological ageing, 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.
They found that adults with higher levels of normal serum sodium were more likely to show signs of faster biological ageing. This was based on indicators like metabolic and cardiovascular health, lung function, and inflammation.
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 findings don’t prove a causal effect, the researchers noted. Randomised, controlled trials are necessary to determine if optimal hydration can promote healthy ageing, prevent disease, and lead to a longer life. However, the associations can still inform clinical practice and guide personal health behaviour.
The National Academies of Medicine, for example, suggest that most women consume around 6-9 cups (1.5-2.2 litres) of fluids daily and for men, 8-12 cups (2-3 litres).
The authors also cited research that finds about half of people worldwide don’t meet recommendations for daily total water intake, which often starts at 6 cups (1.5 litres).
Natalia Dmitrieva, PhD, a study author and researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, commented: “On the global level, this can have a big impact. 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 ageing process and prevent or delay chronic disease.”
