Elevated levels of sodium blunt response to stress, study shows

Apr 05, 2011

All those salty snacks available at the local tavern might be doing more than increasing your thirst: They could also play a role in suppressing social anxiety.

New research from the University of Cincinnati (UC) shows that elevated levels of sodium blunt the body's natural responses to stress by inhibiting that would otherwise be activated in stressful situations. These hormones are located along the hypothalamic-pituitary-adrenal (HPA) axis, which controls reactions to stress.

The research is reported in the April 6, 2011, issue of The Journal of Neuroscience, the official journal of the Society for Neuroscience.

"We're calling this the Watering Hole Effect," says Eric Krause, PhD, a research assistant professor in the basic science division of UC's department of and behavioral neuroscience and first author of the study. "When you're thirsty, you have to overcome some amount of fear and anxiety to approach a communal water source. And you want to facilitate those interactions—that way everyone can get to the water source."

Krause and his team dehydrated laboratory rats by giving them sodium chloride, then exposed them to stress. Compared with a control group, the rats that received the sodium chloride secreted fewer stress hormones and also displayed a reduced cardiovascular response to stress.

"Their blood pressure and heart rate did not go up as much in response to stress as the control group's, and they returned to resting levels more quickly," says Krause.

"Also, in a social interaction paradigm with two rats interacting, we found them to be more interactive and less socially anxious."

Further research, through examination of brain and blood samples from the rats, showed that the same hormones that act on kidneys to compensate for dehydration also act on the brain to regulate responsiveness to stressors and social anxiety.

The elevated level, known as hypernatremia, limited stress responses by suppressing the release of the pro-stress hormone angiotensin II. Conversely, it increased the activity of oxytocin, an anti-stress hormone.

Further research, Krause says, will examine these hormones and neurocircuits to investigate their role in disorders and autism, a neurological disorder whose characteristics include social impairment.

"Oxytocin deficiency has been implicated in autism in previous studies," says Krause. "We'd like to investigate the possibility that dysregulation in fluid balance during pregnancy could result in autistic disorders."

Explore further: Lost memories might be able to be restored, new study indicates

Provided by University of Cincinnati Academic Health Center

4.5 /5 (4 votes)
add to favorites email to friend print save as pdf

Related Stories

Studies expand oxytocin's role beyond 'cuddle hormone'

Nov 15, 2010

New human research suggests the chemical oxytocin — dubbed the "cuddle hormone" because of its importance in bonding between romantic partners and mothers and children — also influences feelings of well-being and ...

Recommended for you

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

dan42day
not rated yet Apr 05, 2011
So now extra salt may be good for us? Pass the pretzels!
Edward_Hampton
not rated yet May 05, 2011
It doesn't necessarily mean that you have to take in salty foods altogether in your diet. It's just stated there that a little more of sodium can "suppress" your anxiety so you would be relieved off panic attacks and other things that are not "normal" to have in nature. I think this article is very good and informative too at most by making this things clear and sound logical.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.