Just as ocean tides rise and fall under the pull of the moon and sun, scientists are discovering that gravitational changes can affect our hearts in subtle ways. We caught up with Guadalupe Rodríguez Ferrante, PhD, who presented her work at the 2026 American Physiology Summit, to learn more about this intriguing topic.

Q: Can you tell us what your team’s work is about?

A: We wanted to know if human cardiovascular function follows rhythmic patterns synchronized with tidal changes in local gravity caused by the moon and sun’s position throughout the day.

Q: Are you saying our hearts are affected by the moon?

A: In a way, yes. We tracked the heart rate and blood pressure of 215 volunteers continuously for a week. Many participants showed repeated patterns that matched not only the 24-hour day, but also gravitational cycles that occur roughly every 12 and 25 hours.

Q: Did the volunteers live close to the ocean for the tides to affect their heart function?

A: No, the study participants live in Almaty, Kazakhstan—about 1,400 miles from the Arabian Sea.

Q: If they live far from the ocean, why do tides matter?

A: The answer is a little less straight forward that you may expect. We observed a positive association between blood pressure and heart rate and gravity every 12 to13 hours. However, they are not completely aligned—the changing tides preceded the blood pressure changes by a couple of hours. In other words, the body may be responding to environmental rhythms before we’re even aware of them.

Q: Are these changes in our blood pressure and heart rate harmful?

A: There’s no evidence these changes are harmful. They’re small, natural fluctuations— part of the body’s ongoing adjustments to the world around us.

Q: Why does this matter?

A: We already know the body runs on a 24-hour internal clock that affects sleep, hormones and metabolism. Our research suggests there may be additional, quieter rhythms layered on top of that daily cycle.

Understanding these patterns could help scientists better explain changes in sleep quality, daily performance and cardiovascular function. It also opens an entirely new direction for physiology research.

Q: What’s the most important thing you want people to understand about your study?

A: Our bodies react to even the subtlest gravitational shifts. And these signals can influence our physiology and daily functioning.