Oxalates are naturally occurring organic compounds found in various plants and common foods. These compounds are a type of acid produced by plants. This article explores oxalates, their levels in corn, and their potential health implications.
Understanding Oxalates
Oxalates, also known as oxalic acid or oxalate salts, are organic acids found in many plants, including fruits, vegetables, nuts, and grains. In plants, oxalates serve as a defense mechanism against herbivores. The human body can produce oxalate as a waste product and also obtains it directly from the diet.
Once consumed, oxalate can bind with minerals like calcium and iron, primarily in the colon, kidneys, and urinary tract. These compounds, such as calcium oxalate, are eliminated from the body through urine or stool. Some gut bacteria, like Oxalobacter formigenes, can break down oxalate before it’s absorbed, which helps reduce the amount of oxalate in the body.
Oxalate Levels in Corn
Corn contains oxalates, though its levels are moderate compared to some other foods. For instance, sweet corn (fresh or canned) contains approximately 3 milligrams of oxalate per half-cup serving. Air-popped popcorn has about 4 milligrams per cup, while corn tortillas contain around 25.5 milligrams per item.
Cornmeal has a higher oxalate content, with about 32 milligrams per half-cup, and cooked corn grits contain approximately 49 milligrams per half-cup. For perspective, foods known for high oxalate levels include cooked spinach, which can have around 755 milligrams per half-cup, and rhubarb, with about 541 milligrams per half-cup. Almonds also contain 122 milligrams per ounce.
Health Implications of Corn Oxalates
For most healthy individuals, the oxalate content in corn is not a significant concern. The body effectively processes and eliminates oxalates. However, for individuals susceptible to calcium oxalate kidney stones, dietary oxalate intake warrants consideration.
When oxalate levels in the urine are high, oxalate can bind with calcium to form crystals that can develop into kidney stones. Individuals with a history of kidney stones may benefit from strategies to manage oxalate intake, although dietary calcium intake is often a more significant factor in stone prevention. Eating enough calcium with meals can help bind oxalate in the gut, reducing its absorption. Consulting a healthcare professional or a dietitian is advisable for personalized dietary guidance, especially for those prone to kidney stones.