Antioxidants: HIV
Introduction
Prior to the introduction of highly active antiretroviral therapy (HAART), the prevalence of malnutrition among HIV-infected persons at all stages of immune deficiency was common. [1] Several pre-HAART studies found that HIV-positive patients had higher levels of oxidative stress, and lower antioxidant levels compared with healthy controls. Oxidative stress may enhance viral replication and, in laboratory studies, antioxidants have been shown to inhibit the activation of HIV transcription. [2]
Compared with subjects not on HAART, HIV-positive subjects taking protease inhibitor-based HAART have higher levels of serum antioxidants, including vitamin E and β-carotene. [3] However, it is not clear whether antiretroviral therapy decreases oxidative stress. Other health issues have emerged among patients receiving HAART including HIV-associated lipodystrophy or fat redistribution syndrome. Certain aspects of this syndrome, along with the HAART medications themselves, may be associated with oxidative stress and the increased need for certain antioxidants. [4]
Antioxidant Supplementation
Malnutrition is still a problem among HIV-infected populations in much of the developing world. Among children, periodic supplementation with vitamin A starting at 6 months of age has been shown to be beneficial in reducing mortality and morbidity among both HIV-infected and uninfected children. [5] Among HIV-infected adults, the safety and the efficacy of vitamin A supplements need further study, [6] although adequate dietary intake of this essential nutrient is recommended. [7]
In HIV-positive patients treated with zidovudine (AZT), supplementation with vitamins C and E has been shown to reverse oxidative damage to DNA caused by this treatment. [8]The benefits of antioxidant supplementation have also been demonstrated among patients receiving HAART. In one study by Allard et al., [9] HIV-positive subjects were given either a daily combination of vitamins E (800 IU) and C (1000 mg) or placebo for 3 months. Significantly lower levels of oxidative stress, measured with breath pentane and plasma lipid peroxides and malondialdehyde (MDA), were noted among the supplemented subjects compared with the placebo group. In a study by Jaruga et al., [10] HIV-positive subjects assigned to receive either a supplement containing vitamin A, C, and E or a placebo were compared. In this experiment, antioxidant supplementation resulted in decreased levels of modified lymphocyte DNA, lower levels of thiobarbituric acid reactive substances (TBARS), and improved antioxidant enzyme activity.
Critical Thinking Questions:
- Should supplements of antioxidant nutrients be included as an adjunct to retroviral treatment?
- How might an oxidant/antioxidant imbalance contribute to the complications arising from HIV?
- Do all antioxidant micronutrients benefit HIV-infected persons?
- At what dosages might antioxidant supplements become harmful to HIV patients?
Links:
Professional Societies, Universities, and Government Organizations:
Society for Free Radical Biology and Medicine (SFRBM):
Virtual Free Radical School
http://www.medicine.uiowa.edu/FRRB/VirtualSchool/Virtual.html
University of Colorado Health Sciences Center,
Webb-Waring Institute for Cancer, Aging, and Antioxidant Research:
Antioxidant Research – AIDS:
http://www.uchsc.edu/sm/waring/webpages/secondlevel/science/aids.html
Tufts University School of Medicine:
Nutrition and HIV Research
http://www.tufts.edu/med/nutrition-infection/hiv/links.htmlHIV Nutrition & Health
http://www.tufts.edu/med/nutrition-infection/hiv/health_high_quality_diet.html
The Body – The Complete HIV/AIDS Resource:
Vitamins, Minerals and Trace Elements
http://www.thebody.com/jossey/romeyn.html
NCCAM