We know that water is essential for life. But hydration may matter for more than avoiding thirst or dehydration.
Water helps maintain blood volume, regulate body temperature, transport nutrients and support normal kidney function. It is also necessary for removing metabolic waste through the kidneys and urine.
As we learn more about healthy aging, researchers are asking another question: could maintaining good hydration over many years also be related to how well we age?
Hydration May Be Linked to Long-Term Health
A large US population study followed adults for approximately 25 years.
Researchers found that people with higher levels of sodium in their blood during middle age had a greater likelihood of developing major chronic diseases and dying earlier.
Why is sodium relevant to hydration?
The concentration of sodium in the blood is partly influenced by the balance between water and dissolved substances. When less water is available, sodium concentration can rise — even while remaining within the conventional laboratory reference range.
In this study, higher-normal sodium was therefore used as an indirect indicator of potentially lower habitual hydration.
What About Biological Aging?
The researchers also estimated participants’ biological age using several clinical measures of how different body systems were functioning.
People with serum sodium above 142 mmol/L were more likely to have an estimated biological age greater than their chronological age.
Higher sodium was also associated with a greater long-term risk of chronic disease. At levels above 144 mmol/L, it was associated with a higher risk of premature death.
This does not mean that 142 mmol/L represents a new threshold for dehydration. Nor does it mean that drinking more water will automatically lower your biological age.
It does suggest that long-term water balance may be relevant to healthy aging and deserves further study.
Good Hydration Does Not Mean Drinking as Much as Possible
Hydration needs are individual.
They depend on body size, physical activity, climate, diet, age, kidney function, medications and medical conditions. Some people with heart or kidney disease may also require specific advice about fluid intake.
The goal is therefore not maximum water intake, but appropriate hydration.
Current research has not yet shown that simply increasing water intake makes people live longer. But maintaining normal water balance is fundamental to healthy physiology — and emerging evidence suggests it may also be relevant to maintaining health over the long term.
Based on Research
Dmitrieva NI, Gagarin A, Liu D, Wu CO, Boehm M. Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality. eBioMedicine. January 2023.
