Experts dig into the possible effects of this popular carbonated beverage.

Reviewed by Dietitian Alyssa Pike, RDN

Key Points

• Dark-colored sodas with phosphoric acid and added sugar may harm kidney health over time.


• High added sugar intake can increase risks of diabetes, hypertension and chronic kidney disease.


• Experts recommend water, sparkling water and unsweetened beverages for better kidney health.

The kidneys are a pair of organs that play a central role in hydration and electrolyte balance. When they’re functioning as they should, you can easily go through the day without thinking about the work they’re doing behind the scenes. Many lifestyle factors, including your diet, are important in helping to maintain healthy kidney function. “If you do not have kidney disease, a general healthy diet can play a huge role in preventing it,” says Melanie Betz MS, RD, CSR, FNKF, FAND. “Kidney disease is usually caused by either poorly controlled high blood pressure or diabetes, so anything that helps prevent these health conditions is good for your kidneys.”, One popular drink—dark-colored sugar sweetened sodas—may be causing more harm than good when it comes to your kidneys and overall health, even in those with healthy kidneys. Registered dietitians explain why and provide a few healthier alternatives.

They Contribute Phosphoric Acid

Some foods naturally contain phosphorus, while others have it added during processing. Phosphoric acid, derived from phosphorus, is found in many dark-colored sodas. Consuming too much of it can be a concern for people with compromised kidney function. “This additive is used for flavor and acts as a preservative and stabilizer to retain the colas color and taste over time,” says Lindsay Ducharme, RD, CSR, LDN. “In people with chronic kidney disease (CKD), excess phosphorus can accumulate in the blood when the kidneys are no longer able to excrete it efficiently,” says Vanessa Connolly, RDN, CSR, LD. “Over time, this may contribute to CKD progression, mineral and bone disorders and increased cardiovascular risk.”

Studies suggest that the added form of phosphorus is absorbed and used differently by the body than the phosphorus that occurs naturally in foods. “Because phosphorus from additives is more readily absorbed, higher exposure to added phosphorus has been linked with lower kidney function (eGFR) in population data,” says Talia Follador, RDN, LDN.

Contain Added Sugars

Many dark-colored sodas contain added sugar that far exceeds the recommended daily intake, especially if drinking more than one per day. The goal is to consider your overall diet, not worry about enjoying one soda from time to time. “The concern is less about a single soda and more about habitual, high intake over time,” says Connolly. Diet patterns that include too much added sugar increase the risk for certain chronic health conditions that can then lead to kidney disease or impaired kidney function. “High consumption of added sugars, particularly from sugar-sweetened beverages, is associated with increased risk of hypertension, Type 2 diabetes, metabolic syndrome and obesity,” says Connolly. “All of these are risk factors for chronic kidney disease.”

May Impact Overall Hydration

Your hydration status impacts your overall kidney function. Some research suggests those who prioritize water (as opposed to sweetened beverages) tend to be better hydrated overall. “Dehydration can cause kidney damage, so it is important to drink plenty of fluid overall, mostly from water,” says Betz. Though it’s okay to reach for a sweetened beverage occasionally, prioritizing low sugar or no sugar beverages can keep you well hydrated and your kidneys happy.

Healthier Alternatives

Not sure what to drink instead of soda? Here are a few dietitian-approved recommendations.

• Water: “Water supports waste filtration, helps prevent kidney stones, and naturally helps regulate sodium balance,” says Talia Follador. While hydration needs vary, drinking primarily water to thirst is a good way to stay adequately hydrated.


• Sparkling Water or Infused Water: “Infused water with lemon, lime, cucumber or herbs is a great way to add flavor without adding unnecessary minerals,” says Follador. “Flavored seltzer waters can also be a good option, just with a quick label check for added sodium, phosphorus additives or sugar.”


• No Added Sugar Fruit Juice: Fruit juice made without added sugar is a great option when you’re looking for a drink that also offers a boost of some vitamins and minerals.


• Cow’s Milk: An often-overlooked beverage for hydration is cow’s milk, which may come with benefits to the kidneys. “If you do not have kidney disease, milk is another wonderful beverage that can dramatically reduce the risk of kidney stones,” says Betz.

Our Expert Take

Dark-colored, sugar-sweetened sodas may harm kidney health due to their phosphoric acid and added sugar content. Phosphoric acid, found in many dark sodas, is absorbed differently by the body and can be an issue in those with compromised kidney function. Consuming too much added sugar can lead to chronic diseases such as hypertension or Type 2 diabetes, both of which are risk factors for chronic kidney disease. Experts recommend choosing healthier alternatives like water, sparkling water or unsweetened cow’s milk to support optimal kidney function and overall hydration.