Drinking eight glasses a water a day throughout your life could reduce the risk of heart failure 25 years later, according to new research.

The findings, presented on August 24 at the European Society of Cardiology Congress 2021, suggest that maintaining good hydration can slow down or even prevent changes within the heart that lead to heart failure, said study author Natalia Dmitrieva, PhD, a researcher at the National Heart, Lung, and Blood Institute, part of the National Institutes of Health (NIH) in Bethesda, Maryland, in press release.

“The findings indicate that we need to pay attention to the amount of fluid we consume every day and take action if we find that we drink too little,” said Dr. Dmitrieva.

How much water is enough? The recommended amount of fluid for men is about 15.5 cups (3.7 liters) for men and 11.5 cups (2.7 liters) of fluids a day for women, according to the National Academies of Sciences, Engineering, and Medicine. That includes all beverages (not just water) and even food; about 20 percent of your fluid intake comes from food.

Serum sodium level is a measurement of how much sodium is your body — the more hydrated you are, the lower your serum sodium will be. This test is a part of routine yearly bloodwork, says Maria Mountis, DO, cardiologist and heart failure specialist at Cleveland Clinic in Ohio, who was not involved in this research. “We use this along with other lab markers that look at kidney function to assess someone’s hydration status,” she says.

Lack of Fluids May Set Off Processes That Lead to the Development of Heart Failure

According to the authors, when people drink less fluid and the concentration of serum sodium goes up, the body attempts to conserve water, which then activates processes known to contribute to the development of heart failure.

Heart failure is when the heart isn’t pumping as well as it should be. When a person has heart failure, the cells in the body don’t get enough blood, which can cause fatigue and shortness of breath, according to the American Heart Association (AHA).

To determine if hydration (measured by the level of serum sodium in the body) could be a predictor of heart failure 25 years, researchers looked at 15,972 people between the ages of 44 and 66 years old. Participants were evaluated over five visits until age 70 to 90.

Subjects were placed into one of four groups according their average serum sodium concentration level, which was based on two visits during the first three years of the study: 135 to 139.5, 140 to 141.5, 142 to 143.5, and 144 to 146 millimoles per liter (mmol/L). For each sodium group, the researchers then analyzed the proportion of people who developed heart failure and left ventricular hypertrophy at visit five (25 years later). The left ventricle is the heart’s main pumping chamber, and when the walls of the chamber get thicker (called hypertrophy) it can be a precursor to a heart failure diagnosis.

After controlling for factors that can contribute to heart failure, such as age, blood pressure, body mass index (BMI), and smoking status, higher serum sodium level concentration in midlife was associated with both heart failure and left ventricular hypertrophy.

Every 1 mmol/L increase in serum sodium concentration was associated with a 20 percent increased risk of developing left ventricular hypertrophy and an 11 percent increased risk of heart failure, 25 years later.

Drinking Plenty of Water and Limiting Salt Just One Component of Heart Health

“I recommend that my patients drink water compared to other liquids and certainly limit salt consumption. Our bodies are certainly very adept at maintaining all of these electrolytes in balance, but we have to also provide what the body needs by drinking enough water and limiting salt intake,” says Dr. Mountis. It’s also important to check in with your physician who review your lab work and health status to give you appropriate guidance, she adds.

Although hydration may play a role, it’s just one aspect in how to prevent heart failure, says Mountis. “It’s important to note that the most common risk factors for developing heart failure are still high blood pressure and coronary artery disease. These are absolutely very modifiable with a healthy diet, management of blood pressure, and avoiding excess toxins to the body,” she says.

Need a little extra help getting enough water? Erin Coates, RD, a registered dietitian and health coach at the Cleveland Clinic in Ohio, suggests putting five rubber bands around a 16-ounce water bottle every morning. Every time you finish a bottle, take one of the bands off, with the goal of removing all five bands by the time you go to bed.