In preliminary research, beetroot juice reduced blood pressure in hypertensive people. Tentative evidence has found that dietary nitrate supplementation, such as from beets and other vegetables, results in a small improvement in endurance exercise performance. Betanin, obtained from the roots, is used industrially as red food colorant, to improve the color and flavor of tomato paste, sauces, desserts, jams and jellies, ice cream, candy, and breakfast cereals, among other applications. The chemical adipic acid rarely occurs in nature, but happens to occur naturally in beetroot. The red colour compound betanin is not broken down in the body, and in higher concentrations may temporarily cause urine or stools to assume a reddish colour, in the case of urine a condition called beeturia. Although harmless, this effect may cause initial concern due to the visual similarity to what appears to be blood in the stool, hematochezia (blood passing through the anus, usually in or with stool) or hematuria (blood in the urine). Nitrosamine formation in beet juice can reliably be prevented by adding ascorbic acid.