Whether sugar is high in oxalates is a common question for people managing their diet, especially those with certain health concerns. Oxalates are naturally occurring compounds found in many foods, and their presence is a factor in dietary planning. Understanding the oxalate content of common table sugar requires looking closely at what these compounds are and how the refining process affects them. This analysis focuses on the oxalate levels in refined sugars compared to other food sources.
What Oxalates Are and Why They Matter
Oxalates, also known as oxalic acid, are organic compounds found in many plant tissues, functioning in mineral regulation and defense. When consumed, oxalates are considered an antinutrient because they bind to minerals, primarily calcium, within the digestive tract. This binding reduces mineral absorption.
Once absorbed into the bloodstream, oxalates are filtered by the kidneys and excreted in the urine. The primary health concern related to high oxalate intake is the formation of kidney stones; approximately 80% of all kidney stones are composed of calcium oxalate crystals.
The body produces some oxalate internally, but dietary intake contributes significantly to the total amount circulating. If the concentration of oxalate in the urine becomes too high, it can crystallize with available calcium, forming stones. Minimizing high-oxalate foods is a common dietary recommendation for individuals prone to this condition.
The Oxalate Content of Refined Sugars
Highly refined sugars, such as common granulated white table sugar, contain negligible levels of oxalates. The extensive manufacturing process required to produce pure sucrose effectively strips away all plant-based impurities, including oxalates. A typical teaspoon of white sugar contains essentially 0 milligrams of oxalates, making it a non-issue for a low-oxalate diet.
The source of the sugar (sugar cane or sugar beet) does not change the final product’s oxalate content because refining isolates the sucrose molecule. Raw sugar cane and sugar beets contain oxalates, but purification removes the non-sugar components that carry these compounds. The final product is nearly 100% pure sucrose.
Less-refined sugar products retain more original plant matter and thus contain slightly higher oxalate concentrations. Brown sugar, typically white sugar mixed with molasses, contains about 1 milligram of oxalate per teaspoon. Molasses, a viscous byproduct of refining, retains the highest amount of residual plant components. Full-flavor molasses can contain around 6 milligrams of oxalate per tablespoon, a moderate level far lower than many common vegetables.
Major Non-Sugar Dietary Oxalate Sources and Management
Since refined sugar is not a significant source of oxalates, individuals concerned about intake should focus on foods where the compounds are concentrated. Many healthy plant-based foods contain high levels of oxalates, including leafy greens, nuts, and cocoa. Spinach is one of the highest sources, with a half-cup serving of cooked spinach containing hundreds of milligrams of oxalates.
High-oxalate foods include almonds, rhubarb, beets, and black tea. For those susceptible to calcium oxalate kidney stones, dietary management focuses on two primary strategies:
Dietary Strategies
The first strategy involves pairing oxalate-rich foods with a source of calcium. This ensures the oxalate binds to the calcium in the gut before it can be absorbed, reducing the amount of free oxalate that reaches the kidneys.
The second strategy involves specific food preparation and hydration. Boiling certain vegetables, like spinach, can reduce their oxalate content by leaching the soluble compounds into the cooking water, which is then discarded. Maintaining a high fluid intake helps dilute the concentration of minerals and oxalates in the urine, discouraging the formation of crystals.