Soft Drinks with Potassium Citrate

Processed foods and beverages often contain non-nutritive substances added to enhance the products in some way, be it for flavoring, coloring or preserving. Potassium citrate is an additive found in soft drinks as well as candy and ice creams. The U.S. Food and Drug Administration deemed it GRAS -- generally recognized as safe -- in 1977.

Potassium citrate is a prescription medication that reduces the acidity of urine to prevent kidney stones. It's also used as an additive in some sodas as a buffering agent to reduce and balance the tart flavor. Potassium citrate is made of the mineral potassium and the substance citrate, which is a sour salt. The sour characteristic of citrate helps to mask the acidic taste of soda and to provide a more pleasant, balanced tart flavor.

Carbonated soft drinks that have a tart citrus flavor may contain potassium citrate, according to Ruth Winter, author of "A Consumer's Dictionary of Food Additives." Lemon, lime, mandarin, grapefruit, tangerine, orange and clementine are examples of soft drink flavors that may contain potassium citrate. Because sugar replacements often have a less appealing flavor, diet drinks labeled sugar-free, regardless of flavor, may contain potassium citrate as well. Check the ingredient list if you want to know whether a soft drink contains this additive.

Scientists who studied the effects of consuming soft drinks containing potassium citrate on kidney stone risk published their findings in the March 2009 issue of the Journal of Endourology. The researchers tested different sodas for the risk of kidney stone development in healthy adults. According to the results, a decrease in uric acid was seen in participants who drank the soda containing potassium citrate. Elevated uric acid levels can cause gout. The authors found no kidney stone risk -- or benefit -- from drinking potassium-citrate-containing soft drinks, however.

Potassium citrate may cause gastrointestinal upset in those who have a sensitivity to it. Symptoms include nausea, abdominal discomfort and loose stools. Avoid drinking beverages that contain this additive if you experience side effects due to sensitivity. Because it is a source of potassium, it is not a good fit for the low-potassium diet you should follow if you have kidney disease.