Low-Oxalate Diet And Seaweed

Oxalate is a simple compound found in many foods, including fruits and vegetables. Once consumed, oxalate binds to calcium in your body and, under certain circumstances, it crystallizes to form mineral deposits and stones. Oxalate also interferes with other minerals and nutrients, so minimizing it in your diet may be helpful, especially if you have been diagnosed with kidney stones, arterial calcifications or mineral deficiencies. Seaweeds are not high in oxalate, but they contain enough of it to be excluded from some low-oxalate diets.

OXALATE

Oxalate, also known as ethanedioate, occurs in plants due to the incomplete oxidation of carbohydrates. Oxalate is useful to many plants because it retards infection and deters animals and insects from eating the plants. Oxalate crystals cause physical irritation to the mouths and digestive tracts of insects and animals and, in large doses, it is toxic, according to the book “Human Metabolism: Functional Diversity and Integration.” Oxalate readily binds to calcium and also interferes with the roles of many other positively charged ions such as magnesium, zinc, copper, iron and manganese. As such, oxalate affects enzyme function, metabolism, digestion, bone mineralization and organ function, especially that of the kidneys, which are common sites for calcium oxalate stones.

FOODS HIGH IN OXALATE

Oxalate is present in many plants and fruits that you eat. According to the book “Principles and Practice of Phytotherapy: Modern Herbal Medicine,” foods especially high in oxalate include almost all seeds and nuts, most berries, rhubarb, buckwheat, black pepper, parsley, spinach, beets, carrots, olives, potatoes, beans, cocoa, chocolate and tea leaves. Ordinarily, your digestive tract won't absorb much oxalate, but when your intestines are inflamed, much more is absorbed. Oxalate also can be generated in your body when you take high doses of vitamin C or consume high levels of fructose.

OXALATE IN SEAWEEDS

Seaweeds, such as kelp, contain only moderate amounts of oxalate and are not linked to higher risks of calcium oxalate stone formation, according to the book “Superfoods: The Healthiest Foods on the Planet.” Although seaweeds contain much less oxalate compared to other green plants such as spinach and Swiss chard, you may need to eliminate seaweeds if you decide to embark on a strict low-oxalate diet. Aside from oxalate content, seaweeds are excellent sources of iodine and contain many vitamins and minerals.

CAUTIONS

An estimated 80 percent of kidney stones are formed from calcium oxalate, and its crystals can also inflame joints, according to the book “Human Biochemistry.” As such, those with kidney disorders, gout, rheumatoid arthritis and chronic vulvar pain are usually advised to avoid foods high in oxalate. Ask your doctor if the health benefits of consuming seaweeds outweigh any potential health risk.