A major study, led by the Radboud university medical center in the Netherlands, has shown that fluid restriction in people with stable heart failure offers no health benefits. On the contrary: it mainly causes thirst and discomfort. Whether patients drink less or not, there are no differences in overall health, hospital admissions, mortality, or medication use. The only
notable difference is that those on fluid restriction experience more thirst. This is the first
study to examine the effects and necessity of reduced fluid intake in heart failure. The
research was supported by the Dutch Heart Foundation.
Heart Failure
In the Netherlands, one in five people will develop heart failure during their lifetime. The
condition is most common in people over the age of sixty. Heart failure occurs either when
the heart muscle can’t contract effectively or when the heart chambers become stiff. In both cases, the heart has difficulty pumping blood around the body, often leading to fluid buildup in the lungs and elsewhere.
Never Proven
Many people at risk of heart failure are advised to limit their fluid intake to no more than 1.5
liters per day. Excess fluid is thought to put extra strain on the heart, but this has never been
scientifically proven. Fluid restriction, however, has many disadvantages. Study leader and
cardiologist Dr. Roland van Kimmenade explains: “Patients feel thirsty. They must track their fluid intake every day. It’s burdensome and a constant reminder of their illness.”
Drinking Based on Personal Need
A total of 506 men and women with stable heart failure participated in the study. Half were
advised to drink no more than 1.5 liters per day, while the other half could drink according
to their own needs. The researchers monitored the patients for three months, assessing
health status, quality of life, thirst, and safety. The study was conducted across seven Dutch
hospitals.
Fluid Restriction Not Necessary
Those assigned to fluid restriction did indeed consume less than 1.5 liters per day, while
those without restrictions drank approximately 300 milliliters more per day. “That may not seem like much, but it was apparently enough to prevent thirst,” says PhD candidate Job Herrmann. Van Kimmenade emphasizes: “For people with stable heart failure, fluid restriction is not necessary. This finding is of global importance and can be immediately applied in clinical practice. However, we studied a specific patient group, so the results may not apply to all individuals. That’s why it’s essential for patients to first consult their healthcare team before adjusting their fluid intake.”
Read the full study results in the journal Nature Medicine at this link
Summary by Louise Bouman
Citation
Herrmann, J.J., Brunner-La Rocca, HP., Baltussen, L.E.H.J.M. et al. Liberal fluid
intake versus fluid restriction in chronic heart failure: a randomized clinical trial. Nat Med
(2025). https://doi.org/10.1038/s41591-025-03628-4
