Salt 4- Sympthetic nervous system

We've previously discussed the function of the autonomic nervous system (ANS).  The ANS is fundamentally divided into the sympathetic (fight or flight) and parasympathetic (rest and digest) divisions.  As a general rule, our body is predisposed toward sympathetic dominance when we don't take care of ourselves.  In other words, when you don't eat/sleep/exercise well & carry too much stress, your body tends to become imbalanced in this department and drive toward overexpression of the sympathetic nervous system.

For example, your blood pressure tends to go up.  Your heart rate tends to go up.  Your ability to digest food goes down.  You respiration rate tends to go up.  All of these are associated and caused by the sympathetic nervous system.

As mentioned, Americans consume way too much salt.  It appears that salt drives the sympathetic nervous system towards overactivity.  A paper from the University of Texas states,

"In recent years, studies have shown that SNA (sympathetic nervous activity) can rise as a result of both acute and chronic increases of body fluid osmolality. These findings have raised the possibility that salt-sensitive cardiovascular diseases could result, at least in part, from direct osmosensory activation of CNS sympathetic drive"   J Phys 2010 Sep 15(Pt18) ;588:3375-84

Much of our brain (in its well state) is dedicated toward suppressing this sympathetic drive.  In other words, it keeps the sympathetics in check.  With excessive salt intake, we predispose toward this heightened sympathetic condition.  Remember that as you cook your dinner tonight.