An oxalate, which is also called ethanedioate, is the deprotonated charged form of oxalic acid or an ester of oxalic acid. Oxalates are chemicals that are often found in plant foods but not in most animal foods. Diets with high levels of oxalates, such as sorrel, may result in kidney disease or even death due to oxalate poisoning if eaten in large amounts.
Fruits
Fruits containing some forms of oxalates include blackberries, blueberries, dewberries, dried figs, gooseberries, raspberries (red and black), grapes (Concord), strawberries and tangerines.
Drinks
Drinks containing some forms of oxalates include beer: Lager draft, Tuborg, Pilsner; Bigelow herbal teas (hot brew time of four minutes or longer): Apple Orchard, Fruit & Almond, I Love lemon, Mint Medley, Orange Spice, Perfect Punch, Red Raspberry, Specially Strawberry, Sweet Dreams, Take-A-Break; tea (black and indian); chocolate milk and Ovaltine; green tea; as well as juices containing berries high in oxalates: kale, kamut and kiwi.
Herbs/Spices
These herbs and spices all contain some forms of oxalates: chocolate, ground cinnamon, cocoa, cocoa powder, ginger, lemon peel, lime peel, orange peel, parsley, pepper, pokeweed, sesame seeds and sorrel.
Vegetables
These vegetables all contain some forms of oxalates: celery, collards, dandelion greens, eggplant, green peppers, leeks, okra, parsnips, potatoes, sweet potatoes, pumpkin, rhubarb, rutabagas, spinach, squash (yellow and summer), turnip greens, watercress and yams.
Miscellaneous Foods
These foods also contain some forms of oxalates: whole-wheat bread, Cheerios, escarole, Fig Newtons, garbanzo beans, Graham crackers, graham flour, oatmeal, peanut butter, peanuts, pecans, popcorn, sesame seeds, soy sauce, soybean crackers, soybean tofu, stone-ground flour, sunflower seeds, Swiss chard, wheat bran, wheat germ and whole-wheat flour.
All the foods mentioned herein contain low amounts of oxalates. It is substantial consumption of any of them that has the potential to increase some form of health issues.