BETHESDA, Md. — It’s no secret that drinking lots of water and staying hydrated is essential for robust, strong health in general. Now, researchers from the National Heart, Lung, and Blood Institute reports consistently staying well-hydrated may also lower your risk for heart failure.

We’re not just talking about a single day or week of extra H2O. Scientists clarify that a lifetime’s worth of hydration not only supports overall essential body functioning but also appears to reduce one’s risk of developing any severe heart problems in the future.

Heart failure, which refers to when the heart is unable to pump enough blood to meet the body’s needs, impacts over 6.2 million Americans – just over two percent of the entire U.S. population. It is also more common in older adults (ages 65+).

“Similar to reducing salt intake, drinking enough water and staying hydrated are ways to support our hearts and may help reduce long-term risks for heart disease,” says lead study author Natalia Dmitrieva, Ph.D., a researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, in a media release.

Serum sodium levels are the key

Initially, a round of preclinical research pointed to a connection between dehydration and cardiac fibrosis (the hardening of the heart’s muscles). So, study authors decided to search for similar associations across various large-scale population studies. This process began with a dataset encompassing over 15,000 adults (ages 45-66). All of those individuals had signed up for the Atherosclerosis Risk in Communities (ARIC) study between 1987 and 1989. Since then, they periodically shared information from medical visits over a 25-year period.

Study authors placed special emphasis on adults who displayed healthy hydration levels and did not have heart failure, diabetes, or obesity at the start of the research period. That resulted in about 11,814 adults taking part in the final analysis. Among that group, 11.56 percent (1,366) ended up developing a form of heart failure.

The team measured “hydration status” among participants via several clinical measures, such as serum sodium levels, which tend to increase as the body’s fluid levels decrease. Researchers report that keeping track of serum sodium levels proved quite useful in terms of identifying those at an increased risk of heart failure. Levels of serum sodium also helped zero in on older adults at risk of both heart failure and left ventricular hypertrophy (enlargement and thickening of the heart).

More specifically, adults with serum sodium levels beginning around 143 milliequivalents per liter (mEq/L) in middle age had a 39 percent associated increased risk of heart failure in comparison to others with lower levels. Doctors consider a normal range of serum sodium to be 135-146 mEq/L. Moreover, for every single 1 mEq/L increase in serum sodium within the normal range of 135-146 mEq/L, the chances of a person developing heart failure increased by a full five percent.

How many cups of water do you need?

Additionally, among a group of 5,000 older adults (ages 70-90), individuals with serum sodium levels measuring 142.5-143 mEq/L during middle age were 62 percent more at risk of developing left ventricular hypertrophy. Serum sodium levels starting at 143 mEq/L also correlated with an astounding 102 percent increase in left ventricular hypertrophy risk and a 54 percent jump in heart failure risk.

With all of these findings in hand, the research team concludes a serum sodium level above 142 mEq/L in middle age leads to an elevated risk of both left ventricular hypertrophy and heart failure later on in life.

Moving forward, the research team says a randomized, controlled trial is needed to confirm these promising but ultimately preliminary results. Still, the findings speak for themselves: Drink more water more often and your heart will thank you in the long run.

“Serum sodium and fluid intake can easily be assessed in clinical exams and help doctors identify patients who may benefit from learning about ways to stay hydrated,” adds Manfred Boehm, M.D., who leads the Laboratory of Cardiovascular Regenerative Medicine.

For reference, study authors generally recommend that adult men drink eight to 12 cups (2-3 liters) of water daily. Women should consume at least six to eight cups (1.5-2.1 liters) on a daily basis.

The study is published in the European Heart Journal.