Boric acid is a weak acid that forms a white, water-soluble powder. It occurs naturally in seawater, is found in many plants and most fruits, and has been used since ancient Greek times for cleaning and food preservation. Modern research is finding a basis for the use of boric acid in human health and medicine.
A study published in the July 2010 journal "Experimental and Toxicologic Pathology" tested the antioxidant capacity of boric acid with regard to its ability to detoxify the body from heavy metal poisoning. The study looked at genotoxicity -- DNA damage -- to white blood cells induced by arsenic, bismuth, cadmium, mercury and lead in human blood cultures. Oxidative stress was also evaluated by measuring the levels of glutathione -- an antioxidant molecule -- in red blood cells. The study found that boric acid significantly reduced the genotoxic effects caused by low doses of these heavy metals. The researchers conclude that, based on its antioxidant properties, boric acid may play a protective role in the body and may be useful in the development of functional foods and medicines.
The ability of boric acid to inhibit the growth of candida albicans was documented in an article published in the February 2009 "Journal of Antimicrobial Chemotherapy." Test-tube preparations of candida albicans were tested using concentrations of boric acid that are safe enough to use as a topical treatment for a human yeast infection. The researchers found that when they varied temperature and boric acid concentration, the yeast were more resistant to higher concentrations of boric acid at cold temperatures. They conclude that boric acid is effective as a therapeutic tool, and they postulate that boric acid works by inhibiting the ability of the fungi to carry out metabolism.
Anti-cancer effects of boric acid were found on melanoma, a form of skin cancer, in a study published in the August 2009 journal "The Analyst." Boron is found naturally in foods and drinking water, and in locations where levels are low, a correlation has been found with a higher incidence of cancer. The study found that viability of melanoma cells decreased with an increasing concentration of boric acid, and the researchers concluded that high concentrations of boric acid have an anti-proliferative effect via promoting apoptosis -- programmed cell death -- of melanoma cells.
Another study published in the August 2008 "Cell Adhesion and Migration" found a similar result with breast and prostate cancer cells. The study compared boric acid with a close molecular relative called phenylboronic acid. Both compounds were effective at decreasing cancer cell viability after eight days of treatment; however, phenylboronic acid was found to be the more potent of the two with regard to inhibiting metastatic and proliferative properties of cancer cells.