Drinking enough fluids is important for everyday health, from regulating body temperature to keeping joints cushioned. A study from the U.S. National Institutes of Health (NIH) suggests good hydration may also be linked to healthier aging, fewer chronic diseases and a longer life.

How the study worked

Researchers at the National Heart, Lung, and Blood Institute analyzed health data from about 11,000 adults who were followed for roughly 25 years as part of a long-running heart study. Instead of asking people how much they drank, the team looked at sodium levels in the blood. When people drink less fluid, blood sodium tends to rise, so it serves as a marker of hydration. The findings were published in eBioMedicine.

What the researchers found

• Higher sodium, faster aging. Adults whose blood sodium was in the upper part of the normal range were more likely to show signs of faster biological aging, based on measures such as blood pressure, cholesterol and blood sugar.
• More chronic disease. They also had a higher risk of developing chronic conditions such as heart failure, stroke, diabetes, chronic lung disease and dementia.
• Shorter lives. Higher sodium levels were linked to a greater risk of dying younger.

Lead researcher Natalia Dmitrieva said the results suggest proper hydration may slow aging and prolong a disease-free life. The study shows an association, not cause and effect, and the researchers called for clinical trials to confirm the link.

Previous research in animals had found that lifelong mild water restriction shortened lifespan, which led the team to look for a similar pattern in people.

How much fluid do you need?

Needs vary with age, body size, activity level, climate and health. The National Academies of Sciences suggest an adequate total daily fluid intake of about 2.7 liters (around 11.5 cups) for women and about 3.7 liters (around 15.5 cups) for men. This total includes water from food, which typically provides about 20% of daily intake, as well as all beverages. Thirst and pale yellow urine are useful everyday guides.

Easy tips to drink more

• Carry a water bottle. Having water with you makes it easier to sip throughout the day. A bottle you like, with volume markings, can help.
• Link it to routines. Drink a glass after brushing your teeth, with each meal or after using the bathroom.
• Set reminders. A phone alert or app can nudge you if you tend to forget.
• Add flavor. Infuse water with cucumber, citrus, berries or mint, or try sparkling water.
• Eat water-rich foods. Cucumbers, melons, berries, oranges, lettuce, tomatoes and soups all contribute.
• Drink before you’re thirsty during exercise or hot weather.
• Find a hydration buddy. Friendly reminders or challenges with a friend can help build the habit.

Who should be careful

Older adults may feel less thirsty, so planned drinking throughout the day is especially helpful. On the other hand, people with heart failure, kidney disease or certain other conditions may need to limit fluids. If you have a health condition or take diuretics, ask your doctor how much you should drink.

The bottom line

An NIH study linked good hydration to slower biological aging, fewer chronic diseases and a longer life. Simple habits, like carrying water and eating water-rich foods, make it easy to stay well hydrated.

This article is for general information and isn’t medical advice. Talk with your healthcare provider about your individual needs.

Sources

• Dmitrieva NI, et al. Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality. eBioMedicine, 2023.
• NIH National Heart, Lung, and Blood Institute: Good hydration linked to healthy aging, 2023.
• Mayo Clinic Health System: Tips for drinking more water.