Gallic acid is an organic acid found in foods such as blueberries, apples, flaxseeds, tea leaves, oak bark, walnuts and watercress. Its supplements are available as capsules, ointments and liquid extracts, and have been used traditionally to treat a variety of ailments. The form and dosage depend on the age of the patient and condition being treated. Gallic acid supplements are generally safe to use, although they may interfere with certain blood pressure medications. It is important to consult a doctor before using them to avoid possible adverse reaction and drug interaction.
A 2009 laboratory study published in "Pharmaceutical Research" showed that gallic acid extracted from grape seeds induced the programmed death of prostate cancer cells. However, these results have not been proven in actual clinical cases and should not be used without consulting a doctor.
Another study published in the March 2006 issue of the journal "Toxicological Sciences" states that gallic acid possesses significant anti-inflammatory properties and prevents the expression of inflammatory chemicals including cytokines and histamines. The researchers of the study state that gallic acid may be used to treat inflammatory allergic diseases. However, talk to a doctor before doing so to avoid complications.
Certain animal studies, such as the one published in the May 2010 issue of the “Journal of Pharmacy and Pharmacology,” indicate that gallic acid possesses significant antioxidant activity and may protect the liver from the harmful effects of free radicals that are formed as a result of various metabolic processes in the body. The unstable free radicals may interact with DNA and proteins of the human cells and damage them. However, as with other cases, use gallic acid supplements only under the supervision of a physician.
Gallic acid may also benefit diabetes patients by triggering the release of insulin by the pancreatic cells, says a study published in the January 2010 issue of the “Phytothreapy Research.” However, they may not replace your existing diabetes medications, and do not use them without consulting your doctor.
Fungi, especially Aspergillus flavus and A. parasiticus, produce a harmful toxin known as aflatoxin that can contaminate foods such as nuts, peanuts, corn, wheat and cottonseed. However, gallic acid has the ability to inhibit the enzymes responsible for the production of aflatoxins by the fungi, says the U.S. Department of Agriculture, and may thereby, help develop an environmentally friendly way to deal with aflatoxins. But it is best to consult a physician before using gallic acid.