It’s no secret that salt, while tasty, needs to be limited for the sake of our heart health and blood pressure. But according to new research by the University of Alabama at Birmingham, presented at the Seventeenth International Conference on Endothelin, too much salt could disrupt the circadian rhythm as well. Here’s what they found.
Studying the impact of salt
First things first: it’s important to call out that this research was done in mice (aka, preclinical animal model). While mice have long been used in research to inform clinical pathways in humans, it’s not always guaranteed that results will translate. That said, for the study, researchers wanted to see how salt impacted the circadian rhythms of lab mice.
Some mice were fed a high-sodium diet, and others a regular diet as the control group. The researchers then looked at the mice’s movement and brain activity.
They were specifically looking at a part of the brain called the suprachiasmatic nucleus (SCN), which is what keeps our body clocks regular and in rhythm. Within the SCN are receptors called endothelin B receptors, but outside of the brain, these receptors help to manage sodium levels.
Upon their analysis, the researchers found the mice who had been fed a high-salt diet weren’t following the normal sleep-wake patterns we’ve come to expect from mice through previous research.
Namely, those mice showed much higher neuronal activity at night compared to the control group, despite the SCN typically showing less activity at this time. As the team notes in their research, “Neuronal excitability at night could lead to decline or mistiming of sleep-wake, hormonal, and physiological rhythms.”
Then, when those mice were given an endothelin B receptor blocker, all that late-night neural activity slowed down. So not only was the salt affecting their circadian rhythm, but the team adds that endothelin B receptor blockers (which are used to promote healthy blood pressure), could also potentially influence the circadian rhythms of people who take them.
While we can’t say for sure whether these results will be replicated in humans, we already know too much salt isn’t great for us, anyway. And with quality sleep and a regulated circadian rhythm being so crucial to our overall wellbeing, these findings are simply one more thing to consider when we reach for the salt shaker.
