Sodium and Kidney Health
By Alexandrina Balanean, MPH, MWC
Many people know that eating too much sodium can cause heart problems, but did you know that it can also hurt your kidneys?
What Do Kidneys Do?
Your kidneys are like superheroes that clean your blood and keep you healthy. They filter about 200 liters of liquid every day (that weighs 441 pounds!).1 They remove waste and toxins and get rid of extra water and electrolytes that your body doesn’t need, which leave as urine.1,2 Kidneys also help make hormones that tell your body to make red blood cells.1,2 Plus, they turn vitamin D into a form that your body can use to stay strong and healthy.1,2
Too Much Salt Is Bad For Your Kidneys
Eating too much salty food makes your kidneys work a lot harder.2,3 And you can develop high blood pressure, which can damage them over time.2,3 The National Kidney Foundation recommends that people with high blood pressure or kidney disease should not have more than 1,500 mg of sodium daily.4
Not following this recommendation can be like a figurative kick right in the kidney; here’s what can happen.
Kidney Stones
Kidney stones are like little rocks made of minerals and salt. When your urine gets too thick, the minerals can stick together and make stones.5 Eating high-sodium foods, being overweight, having health problems like high blood pressure, or taking certain medicines can make kidney stones more likely to form. And they can show up anywhere in the urinary system, from your kidneys to your bladder.5
To reduce your risk of kidney stones, it’s important to limit your salt intake and drink plenty of water.5
Chronic Kidney Disease (CKD)
CKD happens when your kidneys start to get weaker and can’t clean your blood as well as they used to—it’s like having a clogged filter. CKD is divided into five stages, with the earlier ones being less severe; stage 1 means mild kidney damage and stage 5 means total or almost total kidney failure.2,3 Unfortunately, even if you and your doctor can manage the cause of your CKD, it can still get worse and lead to kidney failure, for which you would need dialysis or a kidney transplant to survive.2,3
CKD affects a lot of people—about one in seven American adults—but many of them don’t even know they have it.2,3 Complicating things even more, some people are more likely to get CKD than others, such as those with diabetes, high blood pressure, or those who have family members with kidney problems.6 People from certain ethnic backgrounds, like Black/African American and South Asian, are also more at risk.6 But some people might still get kidney disease no matter what they do or don’t do.3 So how can you help your kidneys do their best?
If you already have CKD, fixing what’s causing your kidneys not to work properly is the best thing you can do.2,3 Aside from seeing your doctor, this might mean controlling your blood pressure, managing diabetes, and/or losing weight.2,3 A low-sodium diet helps with all of these.
How Can I Reduce My Risk of Kidney Stones and CKD?
If you don’t already have kidney stones or CKD, one of the best ways to prevent them is to eat less salt.2-7 When you buy packaged foods, check how much salt they have and choose the ones with less salt. And instead of adding salt to your food for flavor, try using herbs and spices like basil, oregano, or cumin. Here are some more tips:
- Know which foods are high in sodium: It’s in almost all foods, including mixed dishes like sandwiches, burgers, tacos, rice, pasta, pizza, meat, poultry, seafood, and soups. It’s not just about the saltshaker; be careful with processed and ready meals because they usually have a lot of sodium.7
- Sea salt is still salt: Sea salt is often thought of as healthier, but it has the same amount of sodium as table salt, around 40%.7
- Check for sodium in medications: Some over-the-counter medications contain high levels of sodium. Read drug labels carefully and consider low-sodium alternatives.7
Taking care of your kidneys is very important for staying healthy, avoiding painful kidney stones, and for keeping your kidneys from getting weaker if you have CKD. Remember, small changes can make a big difference!
- https://pubmed.ncbi.nlm.nih.gov/30855923/
- https://my.clevelandclinic.org/health/diseases/15096-chronic-kidney-disease
- https://www.yalemedicine.org/news/why-is-chronic-kidney-disease-ckd-on-the-rise
- https://www.medicalnewstoday.com/articles/sodium-and-chronic-kidney-disease#risks-of-excess-sodium
- https://www.mayoclinic.org/diseases-conditions/kidney-stones/symptoms-causes/syc-20355755
- https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521
- https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/sodium/7-salty-sodium-myths-busted-infographic