Food grade hydrogen peroxide is a 35-percent solution intended for use in preparing or storing food. Some suppliers use it, for instance, to clean bagged lettuce. Food-grade hydrogen peroxide has a place in certain alternative health practices that adhere to the theory that disease thrives on low levels of oxygen in the body. Food-grade hydrogen peroxide is purported to heal many serious diseases, including cancer and AIDS. The folk remedies website Earth Clinic says side effects do not occur with appropriate dosages of up to 4 drops per 8-ounce glass of distilled water.
Food-grade hydrogen peroxide can damage the gastrointestinal tract. An article in the October 2007 issue of the "Canadian Journal of Gastroenterology" reviewed a case in which a man accidentally consumed 250ml of food-grade hydrogen peroxide, thinking it was water. Examination showed extensive caustic injury to the stomach lining, and some superficial erosions in the first section of the small intestine. The patient was able to leave the hospital on the third day with no complications. The study authors noted that keeping food-grade hydrogen peroxide on hand for alternative health purposes can lead to accidents such as this one. Ingesting this substance can also cause worse effects due to its caustic nature, including gastrointestinal ulceration and perforation.
Caustic injury to the airway can happen if an individual aspirates food-grade hydrogen peroxide, as noted by the "Canadian Journal of Gastroenterology" study. Aspiration involves accidentally breathing liquid into the trachea and lungs while swallowing. Aspirating food-grade hydrogen peroxide can cause narrowing of the airways and laryngospasm, a spasm of the vocal cords that makes it difficult to breathe. These conditions may require a breathing tube and mechanical ventilation.
Hydrogen peroxide in the body can release dangerous amounts of oxygen, according to the "Canadian Journal of Gastroenterology" article. Rapid release of oxygen can cause perforation of the stomach or intestines. Excessive amounts of oxygen in the bloodstream can lead to a gas embolism, or bubble, in the gastrointestinal system or in the brain. A gas embolism in the brain is similar to a stroke.
The U.S. Food and Drug Administration issued a warning on July 27, 2006 in regard to the potential for food-grade hydrogen peroxide consumption to cause gastrointestinal irritation or ulceration. The warning also addressed intravenous administration of hydrogen peroxide, which can cause inflammation of the blood vessel at the injection site, gas embolisms in blood vessels and life-threatening allergic reactions.