I recently saw a patient who suffered from chronic back pain from a herniated disc. He asked me what I thought about O3, or ozone therapy. The best that I could do was to tell him that I would look into it. Allow me to share what I learned.

We’re all aware that there is an ozone layer found in the Earth’s stratosphere, which absorbs most of the sun’s ultraviolet radiation. Ozone is a colorless, water-soluble gas made up of three oxygen atoms (O3). It is a close cousin to ordinary oxygen, which has two oxygen atoms (O2). Ozone has been used clinically since the 1800s. During the First World War, it was used to disinfect wounds, improve blood flow, and serve as an anti-inflammatory.

The theory behind O3 therapy is that increasing the amount of oxygen in the body may help to reduce the clogging of blood cells, detoxify the liver, decrease uric acid in the body, improve circulation and oxygen supply, kill viruses, bacteria and fungus, and improve the activity of white blood cells. Its effectiveness is still unproven for these claims, but ozone therapy is, nonetheless, being used on infected wounds, circulatory disorders, geriatric disorders, macular degeneration, viral diseases, arthritis, SARS (severe acute respiratory syndrome), AIDS, and cancer.

Using a gas as a medical treatment is quite unusual. This gas is available in several forms, including ozonated olive oil, ozonated water, injections, administered directly into the blood stream, blown into the rectum, and as a gas bath or sauna.

Ozone therapy has been considered safe since at least 1980, when a study looked at over 5 ½ million ozone treatments. Side effects are quite minimal. However, when inhaled, ozone is extremely toxic. Those of us who were raised in Southern California will recall the years of smog alerts. Small amounts of ozone and nitrogen dioxide in smog can irritate the lungs and throat, resulting in coughing, shortness of breath, and damage to lung tissue. Ozone therapy carefully avoids ozone inhalation.

But let’s return to my patient, whose question about his herniated disc pain jump-started my education in ozone: Among its many possible applications, ozone therapy is emerging as a potential alternative to steroid injections and surgery for treatment of herniated discs. Both steroid injections and surgery pose potentially significant safety concerns.

Using ozone gas for herniated disc therapy has been practiced in Europe and Asia, and the research to date shows that 65% to 80% of patients have reduced symptoms after treatment. 75% of patients had benefits that lasted through 10 years.

Given that the European evidence suggests low-risk and high reward, why isn’t ozone therapy used more as an option here in the United States? More research is needed to determine the long-term effectiveness and safety of oxygen-ozone injections. Some of the skepticism is based on the fact that a large percentage of herniated-disc patients actually heal, with time, on their own.

Still, ozone therapy is a promising treatment that appears to be safe and may well be effective for a number of health conditions. Research is ongoing.

Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.