Is salt bad for the kidneys?
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The average salt (sodium) intake of an American is about double the daily recommended amount of 5 grams. And, while salt is essential for many bodily functions, too much may raise blood pressure and harm the kidneys.
Good Salt For Kidneys
Humans need sodium to survive. Our bodies use salt to transmit nerve impulses, control muscle contractions, and balance our fluid levels. (1) Too little salt will force the kidneys to keep water and therefore keep salt around.
Bad Salt For Kidneys
Too much salt will cause the kidneys to go into overdrive. The only way to remove the excess salt is by filtering and pushing out as much water as possible. Unfortunately, this forces more protein into the urine, which acts as a risk factor of kidney damage. (2) However, if the salt sticks around, it’ll enter the fluid around cells, bringing more water. The extra volume of fluids makes the heart work harder, putting extra pressure on blood vessels. As a result, these vessels can stiffen and damage. (1)
Blood Vessel Health Matters
The kidneys have thousands of tiny blood vessels and arteries. The blood enters through the renal artery, is filtered, and then removed through the renal vein. If these veins are damaged, it will severely impact their ability to work. Over time, fewer toxins will be able to be filtered from the blood, causing more damage. (3)
Salt and Kidney Stones
The kidneys’ goal is to balance sodium levels to regulate blood pressure. However, high intake forces the kidneys to remove more water than they usually would. During this process, calcium is also pulled along and removed via urine. As a result, minerals may form into kidney stones.
The Take Away
So, salt is not innately bad for the kidneys. Sodium is vital! Ultimately, it’s when consumed in excess can salt become dangerous.
Speak with your healthcare provider regarding your salt intake, blood pressure, and kidney health.
- Publishing, H. (2006). Take it with a grain of salt. Retrieved July 17, 2020, from https://www.health.harvard.edu/heart-health/take-it-with-a-grain-of-salt
- Kidney disease and kidney stones. (n.d.). Retrieved from http://www.actiononsalt.org.uk/salthealth/factsheets/kidney/#:~:text=Urinary%20calcium%2C%20the%20main%20constituent,reduce%20reoccurrence%20of%20renal%20stones.
- Your Kidneys & How They Work. (2018, June 01). Retrieved July 17, 2020, from https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work