Giving selenium, an antioxidant mineral sold as a dietary supplement, to HIV patients modestly reduced the amount of virus in their blood, according to a study published Monday.
Patients taking 200 micrograms of high selenium yeast daily saw an average 12% drop in blood virus levels, according to the study in the Archives of Internal Medicine.
"I liken selenium to a lion tamer in a circus," said lead author Barry Hurwitz, a professor of psychology and medicine at the University of Miami. "What it appears to do is make [the virus] more docile, less virulent and less likely to replicate."
But Dr. Jeffrey Lennox, principal investigator for Emory University's HIV Clinical Trials Unit who was not involved in the study, said selenium's effect appears small, less than a variation that can be seen in some AIDS patients from week to week.
He added that taking selenium also did not have wide clinical implications in the U.S. because there are already antiretroviral therapies here that can decrease the amount of virus in the blood to undetectable levels.
"The conclusions are intriguing, but they don't change current medical practice," Lennox said. "In people not receiving optimum therapy, selenium might be a benefit."
Selenium is a trace mineral in soil that can be absorbed by plants. Cows and other animals can also absorb the mineral if they feed on grain grown in soil with selenium.
Research has linked selenium deficiency to forms of heart disease, hypothyroidism and a weakened immune system. Previous studies also have found that the mineral suppresses HIV replication in the lab and that some HIV patients have lower selenium levels.
Hurwitz's study, which was funded by the National Institutes of Health, looked at 174 HIV patients in the Miami area. About two-thirds of the patients were already taking antiretroviral drugs. About a third were not taking any AIDS drugs.
The study found that the 50 people who regularly took their selenium pills saw the virus in their blood drop by about 10,000 viral particles per milliliter of blood after nine months, a mean decrease of about 12%. The number of immune cells, known as T-cells, increased by a mean of about 30 cells per microliter of blood.
Selenium had a good effect at nine months regardless of what kind of drug regimen the patients were on, Hurwitz said.
The 83 patients in the placebo group saw the amount of virus in their blood increase by 10,000 to 20,000 viral particles per milliliter of blood. Their T-cells diminish by about 30 cells per microliter.
Another group of 41 people, classified as "nonresponders" because they did not adhere to their selenium schedule or because gastrointestinal problems prevented them from absorbing selenium, had about the same results as the placebo group.
Hurwitz and his colleagues are still analyzing the data on selenium's effects beyond nine months, but he said the benefits appear to be sustained
Jeffrey Blumberg, a professor of nutrition at Tufts University, said that because selenium appears to help and has no serious side effects, there is no reason not to use it as booster with traditional therapies.
"Selenium is a simple, inexpensive and safe adjunct therapy," said Blumberg, who was not involved in the study. "It's pretty reasonable to go forward with this."