The study, published in the latest issue of the Archives of Internal Medicine, highlights the need of further research into the role of micronutrients in AIDS management, but it should be stressed that the selenium are not a replacement for standard antiretroviral drugs, but a potential supplement.
"This study is, to our knowledge, the first double-blind, randomized, placebo-controlled trial in a community-based cohort of HIV-infected men and women to demonstrate that daily supplementation with 200 micrograms of selenium for nine months elevates serum selenium level and suppresses the progression in HIV-1 viral load," wrote lead author Barry Hurwitz from the University of Miami.
The placebo-controlled, randomised, double-blind clinical trial looked at the effects of a daily selenium yeast supplement (200 micrograms, provided by Nutrition 21) or placebo on 262 people who were HIV-seropositive (average age 40.6). The average CD4 T-lymphocyte count (the immune system cells that the virus attacks) at baseline was 417 and 441 cells per microlitre of serum for the selenium and placebo groups, respectively, while average baseline serum selenium levels were 113 and 111 micrograms per litre, respectively.
One hundred and seventy-four volunteers completed the nine-month intervention and further nine months of follow-up. Selenium levels in the selenium-supplemented group were found to have increased by 32.2 micrograms per litre, compared to 0.5 micrograms per litre for the placebo group.
Higher blood selenium levels predicted a decreased HIV viral load, which in turn predicted increased CD4 count.
"Selenium-treated subjects whose serum selenium increase was greater than 26.1 micrograms per litre evidenced excellent… adherence (86.2 per cent), no change in HIV-1 viral load, and an increase in CD4 count (+27.9 cells per microlitre)," said the researchers.
Moreover, no adverse events related to the selenium supplements were reported, they said.
"The exact mechanism by which selenium exerts its effects on HIV-1 viral replication is not known, although the literature suggests several possibilities," wrote the researchers.
One hypothesis holds that selenium's antioxidant properties may repair damage done to immune cells by oxygen, which is produced at higher levels in the bodies of patients with HIV. However, future research is needed to confirm this relationship.
The researchers called for more research to investigate whether the indirect effect of selenium on CD4 count is limited to mediating the HIV-1 viral load, and what the mechanism(s) driving the effects is.
"Given the challenges of using conventional pharmacotherapy to achieve and maintain virologic suppression in HIV-spectrum disease, our results support the use of selenium as a simple, inexpensive and safe adjunct therapy," concluded the authors.
The research was welcomed by AVERT, an international HIV and AIDS charity based in the UK. A spokesperson for the charity told NutraIngredients.com that the research "highlights the importance of selenium in the proper functioning of the immune system, and gives good justification for the use of selenium supplements by HIV positive people.
"Further longer term studies should now be carried out to assess whether selenium supplementation could delay an HIV positive person's need to start antiretroviral treatment."
A report published by the World Health Organisation in November 2005 showed that the number of people living with HIV was at its highest ever: 40.3 million. More than 3 million people died of AIDS-related illnesses in 2005, with more than 500,000 of these children.
Source: Archives of Internal Medicine Volume 167, Pages 148-154 "Suppression of human immunodeficiency virus type 1 viral load with selenium supplements" Authors: B.E. Hurwitz, J.B. Klaus, M.M. Llabre, A. Gonzalez, P.J. Lawrence, K.J. Maher, J.M. Greeson, M.K. Baum, G. Shor-Posner, J.S. Skyler, N. Schneiderman