Sugar, potassium, and how the body eliminates salt from its system

So I read that dextrose (sugar) and potassium both have the effect of causing your body to eliminate salt from its system (which is why it is recommended that you eat a banana if you’ve eaten a meal that was too salty,) but how?

Also, how long does it take for sugar and potassium to kick sodium out of the bloodstream?

The American Heart Association recommends potassium (such as bananas) to help flush out sodium and reduce blood pressure, so this isn’t just woo.

According to Harvard Medical School, at least one reason is that sodium is removed from your blood via the kidneys, but that also removes potassium. If your potassium levels are low, the kidneys stop the process so that you aren’t deprived. Putting more potassium into your body can help prevent that.
“ In healthy individuals, the kidneys respond to excess sodium by flushing it out in the urine. Unfortunately, this also removes potassium. If potassium levels are low, the body tries to hoard it, which also means hanging onto sodium. Water follows sodium, leading to an increase in the amount of water in the body and the volume of blood in circulation. Blood pressure climbs, and the heart must work harder. Excess sodium blunts the ability of blood vessels to relax and contract with ease, and may also overstimulate the growth of heart tissue. All of these responses are made worse by low potassium intake.“

If I remember correctly, ion pumps work with potassium and sodium ions. Pull potassium in, push sodium out.


Thanks. How long does it take for the body to flush X amount of sodium out of the bloodstream? Any formula?

One of the symptoms of high blood sugar is continuously needing to go to the bathroom. You body flushes the extra sugar out of itself. I believe the same thing happens when you salt intake is too high, you drink more and then piss more. This doesn’t make it safe to take in too much salt or sugar on a regular basis as I believe this puts a strain on the kidneys.

Okay, I think I misinterpreted your original question.

The sodium-potassium pump is used on a cellular level, so individual cells pull potassium inside the membrane and push sodium out. If you’re asking about sodium regulation in the bloodstream, that’s an entirely different system, as Atamasama mentioned it involves the kidneys. You normally lose sodium through urine, but if the sodium concentration is too low the kidneys produce renin which causes production of aldosterone and angiotesin, which cause the kidney to reabsorb more sodium and excrete more potassium into the urine.

There isn’t going to be a time formula because people’s bodies are different, and we are talking about a passive regulation system here. The rate is affected by a number of factors for example if you drink too much fluid or lose too much fluid (eg: dehydration, diarrhea). But your body is generally supposed to keep the plasma sodium concentration between 135-145 mmol/L at all times.

I’m not a doctor but I believe hypernatremia (high sodium concentration) is generally caused by lack of water more than potassium deficiency. People usually eat enough potassium unless you’re on some weird diet. With enough water your body is supposed to get rid of the sodium on its own. It’s a problem for very old patients who cannot drink enough water.

The reason we inject eg: saline or 5% dextrose is because adding water intravenously is faster than drinking. You can’t use straight water because the red blood cells will rupture if you dilute plasma too fast.