Kidney stones are a common health issue, causing discomfort and pain. These hard deposits form in the kidneys and can affect any part of the urinary tract. Cinnamon, a widely used spice, is often questioned regarding its impact on kidney health and stone formation.
Understanding Kidney Stones
Kidney stones are solid masses composed of minerals and salts that crystallize in the urine. They can vary significantly in size, from as small as a grain of sand to as large as a golf ball. Stone formation occurs when urine becomes highly concentrated with crystal-forming substances, or when substances that normally prevent crystals from sticking together are lacking.
The most common type of kidney stone is the calcium oxalate stone. These stones often form when urine contains elevated levels of calcium and oxalate, or low levels of citrate. Other types include uric acid stones, which can develop in individuals with diets high in animal protein or those with conditions like gout, and struvite stones, often linked to urinary tract infections.
Cinnamon’s Compounds and Kidney Impact
Cinnamon contains various chemical compounds, with coumarin and oxalates being relevant to kidney health. Coumarin is a natural flavoring agent found in cinnamon that can be harmful in large doses. High intake of coumarin over time has been associated with liver toxicity in some individuals. While direct kidney damage from coumarin is not a primary concern, severe liver dysfunction could indirectly affect overall body metabolism and kidney function.
Cinnamon also contains oxalates, naturally occurring compounds that can contribute to calcium oxalate kidney stones. However, the oxalate content in cinnamon as a culinary spice is minor. A significant portion of oxalate in cinnamon is water-insoluble, meaning it is less readily absorbed by the body compared to water-soluble oxalates found in other foods. While cinnamon supplements might contain higher amounts of total oxalate, cinnamon used as a food spice contributes negligibly to the overall dietary oxalate intake for most people.
Distinguishing Cinnamon Varieties
Different types of cinnamon exist, and their chemical compositions vary, especially regarding coumarin content. The two primary varieties are Cassia cinnamon and Ceylon cinnamon. Cassia cinnamon, the most common type sold in North America and often simply labeled “cinnamon,” has a stronger flavor. This variety contains significantly higher levels of coumarin, ranging from 2,650 to 7,017 mg per kilogram, and sometimes up to 1% coumarin by weight.
Ceylon cinnamon, often called “true cinnamon,” is primarily cultivated in Sri Lanka and has a more delicate, sweeter flavor. Ceylon cinnamon contains only trace amounts of coumarin, around 0.004% to 0.02%, making it a safer option for regular or higher consumption.
Cinnamon Consumption and Kidney Stone Risk
For those concerned about kidney stones, the type and quantity of cinnamon consumed are important. Moderate use of cinnamon as a spice in cooking is considered safe for most people, even for those with a history of kidney stones. The European Food Safety Authority suggests a tolerable daily intake of coumarin at 0.1 mg per kilogram of body weight. Consuming just 1-2 teaspoons of Cassia cinnamon can exceed this daily limit for some individuals.
To identify cinnamon varieties, Ceylon cinnamon sticks are lighter in color, with thin, papery layers that form tight, multi-layered rolls, resembling a cigar. Cassia cinnamon sticks are darker, thicker, and consist of a single, hard layer that forms a looser scroll. When purchasing ground cinnamon, it is often difficult to distinguish between the two types, as most products are Cassia unless specifically labeled “Ceylon.” Choosing Ceylon cinnamon for regular or larger daily intake is a practical approach to minimize coumarin exposure. Overall, cinnamon is not a primary dietary factor in kidney stone formation compared to other well-established risk factors like inadequate fluid intake or high sodium consumption.