Staying well-hydrated may help prevent serious heart conditions, according to a new study from Bar-Ilan University. Researchers found that people with higher blood sodium levels—still within the medically accepted “normal” range—are more likely to develop high blood pressure and heart failure.
The study, published in the European Journal of Preventive Cardiology, analyzed 20 years of data from over 407,000 healthy adults enrolled in Leumit Healthcare Services. Those with sodium levels at the higher end of the normal range (140–146 mmol/L) faced a significantly greater risk of cardiovascular problems. Specifically, individuals with sodium levels above 143 mmol/L were 29% more likely to develop hypertension and 20% more likely to develop heart failure.
Rethinking What "Normal" Means
Current clinical guidelines consider sodium levels between 135 and 146 mmol/L to be normal. However, the Bar-Ilan findings suggest that even within this range, higher values may signal health risks. The researchers emphasize that sodium levels reflect hydration status—when people are underhydrated, sodium becomes more concentrated in the blood.
Nearly 60% of participants had sodium levels in the higher-risk range, highlighting how common the issue may be even among healthy individuals.
Small Changes, Big Impact
Lead researcher Prof. Jonathan Rabinowitz says these findings point to hydration as a simple but overlooked part of disease prevention. “A basic blood test could help identify people who would benefit from drinking more water,” he said.
While hydration needs vary based on factors like age, activity level, and climate, U.S. guidelines recommend about 3.7 liters of fluids per day for men and 2.7 liters for women.
By paying closer attention to hydration, people may be able to lower their long-term risk for heart disease with minimal effort.
