Which statement is correct and Why?

Question

The kidneys work harder when you eat a high salt diet or they work harder when you drink lots of water.

Answer 1

The kidney "works harder" when handling salt/ion loads than when handling water loads. Water can be easily filtered from the blood by a number of systems. The salt load, however, requires careful management because of the key ion gradients across the membranes of the kidney. Energy (ATP) is used in the maintenance of these gradients, thus performing "work" - water filtration can be paracellular, driven simply by relative gradients. This is, of course, without consideration of the health issues that come with such a diet.

Answer 2

The kidneys are the body's filtering system. This is where the toxins get caught and later flushed out of the body. If a person eats a lot of salt and not enough water, the kidneys would work harder. With an ample amount of water in the body, they should work normaly. Drinking a lot of water will make the bladder work harder.