Adults maintaining adequate hydration levels exhibit healthier profiles, face a reduced incidence of chronic ailments such as heart and lung disease, and generally enjoy a longer lifespan than those who might not consume enough fluids. This conclusion stems from a study by the National Institutes of Health published in eBioMedicine, which scrutinized health information from 11,255 adults over three decades. The research examined the relationship between serum sodium levels—which rise with decreased fluid consumption—and various health metrics. It was discovered that adults at the upper spectrum of the normal serum sodium range were at a higher risk of developing chronic diseases and showed more pronounced signs of biological ageing than their counterparts with serum sodium levels in the mid-range. Furthermore, those with elevated levels faced an increased likelihood of earlier mortality.
Natalia Dmitrieva, PhD, a principal investigator in this study and a researcher at the National Heart, Lung, and Blood Institute (NHLBI), part of the NIH, suggested that staying adequately hydrated might decelerate the ageing process and extend life free from disease. This analysis builds upon findings published in March 2022, which identified a correlation between higher normal ranges of serum sodium and a heightened risk of heart failure. Both insights originate from the Atherosclerosis Risk in Communities (ARIC) study, which has been instrumental in understanding heart disease risk factors and influencing clinical protocols for its management and prevention.
For this study, researchers delved into data from five medical check-ups of study participants, initially in their 50s and later between 70 and 90 years old. To ensure a reliable comparison of hydration’s impact on health outcomes, individuals with high baseline serum sodium levels or pre-existing conditions affecting serum sodium, like obesity, were excluded. The study assessed serum sodium’s correlation with biological ageing through 15 health markers, such as blood pressure, cholesterol, and blood sugar levels, offering insights into the functionality of cardiovascular, respiratory, metabolic, renal, and immune systems. Adjustments were made for demographic and health-related variables, including age, race, sex, smoking status, and hypertension presence.
Findings indicated that adults within the higher spectrum of normal serum sodium levels (135-146 milliequivalents per litre) exhibited accelerated biological ageing. Indicators pointed to deteriorated metabolic and cardiovascular health, impaired lung function, and increased inflammation. Specifically, serum sodium levels above 142 mEq/L were associated with a 10-15% higher likelihood of advanced biological age compared to levels between 137-142 mEq/L, and levels above 144 mEq/L corresponded with a 50% increase. Additionally, serum sodium levels ranging from 144.5 to 146 mEq/L were linked with a 21% heightened risk of premature death relative to the 137-142 mEq/L range.
Moreover, individuals with serum sodium levels above 142 mEq/L were found to have up to a 64% greater risk of developing chronic conditions such as heart failure, stroke, atrial fibrillation, peripheral artery disease, chronic lung disease, diabetes, and dementia. On the contrary, those with serum sodium levels between 138-140 mEq/L demonstrated the lowest risk of chronic disease development.
While these findings do not establish a direct cause-and-effect relationship, they underscore the necessity for further research through randomized, controlled trials to ascertain whether optimal hydration can foster healthy ageing, avert disease, and extend lifespan. Nonetheless, the associations observed can guide clinical practices and inform personal health decisions.
Dmitrieva emphasized the importance of evaluating fluid intake for individuals with serum sodium of 142 mEq/L or higher. Increasing fluid intake to meet recommended levels through water, juices, or high-water-content fruits and vegetables is feasible and safe for most. The National Academies of Medicine advises that most women consume about 6-9 cups (1.5-2.2 litres) of fluids daily, while men should aim for 8-12 cups (2-3 litres). Specific individuals may require medical advice due to underlying health conditions. Ensuring adequate fluid intake while considering factors like medication-induced fluid loss is crucial, especially for patients with specific treatment plans, such as those limiting fluid intake for heart failure management.
This research highlights a global concern: approximately half of the world’s population needs to meet daily water intake recommendations, typically starting at 6 cups (1.5 litres). The pervasive issue of inadequate hydration, which leads to increased serum sodium levels, underscores the potential of proper hydration in slowing the ageing process and preventing or delaying the onset of chronic diseases. This study, supported by the Division of Intramural Research at NHLBI and the ARIC study funded by NHLBI, NIH, and the Department of Health and Human Services, contributes significantly to our understanding of hydration’s role in promoting health and longevity.
More information: Dmitrieva NI, Gagarin A, Liu D, et al, Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality, EBioMedicine. DOI: 10.1016/j.ebiom.2022.104404
Journal information: EBioMedicine Provided by National Heart, Lung, and Blood Institute
