Preliminary evidence suggests eating more foods containing glucaric acid may help limit cancer risk by inhibiting an enzyme called beta-glucuronidase, according to an article published in Cancer Therapies in June 2003. Glucaric acid, also called calcium glucarate or saccharic acid, is found in many plant foods, at least in small amounts.
Apples and grapefruit are among the fruits highest in glucaric acid and have about 350 milligrams per 100-gram serving. Grapes are much lower in glucaric acid, with about 10 milligrams per 100-gram serving, and apricots, oranges and cherries fall somewhere in between in their glucaric acid content, according to an article published in the Journal of Nutrition in June 2002.
Bean sprouts and cruciferous vegetables like cabbage, broccoli and Brussels sprouts tend to be high in glucaric acid, with about 350 milligrams per 100-gram serving. Tomatoes provide a significant amount of glucaric acid as well, but lettuce is low in glucaric acid with about 10 milligrams per 100-gram serving, according to the Journal of Nutrition article. Authors of a classic study published in Biochemical Medicine and Metabolic Biology noted that the broccoli and potatoes they tested had less than 2 milligrams of glucaric acid per 100-gram serving, however, so glucaric acid content may vary in the same food.
Kombucha is a fermented tea made by adding a type of fungus and sugar to black or green tea. It contains a form of glucaric acid, but the exact amount will depend on the fermentation time, the type of tea and the amount of sugar used. You shouldn't drink more than 1/2 cup of this tea per day, however, according to the Columbia University Health Services website.
Glucaric acid isn't an essential nutrient, but supplement manufacturers often recommend a dose of between 200 and 400 milligrams of glucaric acid per day for health benefits. It's hard to figure out just how much is in a particular food, however, making it difficult to know if you're meeting this goal.
Check with your doctor before taking glucaric acid supplements because these could increase the speed at which certain medications leave your body, making them less effective. Glucaric acid may interact with entacapone, hormone replacement and birth control medications, for example.