Part One of this blog post presented scientific reviews published in Advances in Nutrition that explored links between nutrition and the prevention and treatment of viral infection. Part Two looks at relevant articles published in The American Journal of Clinical Nutrition, The Journal of Nutrition, and Current Developments in Nutrition.
The Ebola virus epidemic in West Africa that occurred between 2014 and 2016 resulted in more than 28,000 infections and more than 11,000 deaths. Liberia and Sierra Leone bore the brunt of the disease.
Research has shown that micronutrient supplementation is a key part of supportive care for Ebola virus patients. In particular, vitamin A, which is found in such foods as spinach, dairy products and liver, has been proven to bolster immunological response to infectious disease. It therefore has been posited that vitamin A supplementation could help patients with Ebola virus disease.
“The observed mortality of patients treated early with 200,000–400,000 IU of vitamin A was significantly lower than patients who were not treated.”
Working with a retrospective cohort of 424 Ebola virus patients in Liberia and Sierra Leone, Adam R. Aluisio et al. evaluated the impact of early vitamin A supplementation (i.e., beginning with the first or second day of treatment) on mortality. Treatment guidelines included vitamin A supplementation for all patients; however, due to a lack of resources, not all patients received it, allowing a comparison between those who received vitamin A and those who didn’t.
According to the authors’ findings, “the observed mortality of patients treated early with 200,000–400,000 IU of vitamin A was significantly lower than patients who were not treated.” In fact, the mortality rate among patients treated with vitamin A supplementation was 55.0%, compared to 71.9% for those not given vitamin A.
American Journal of Clinical Nutrition “Zinc Supplementation Decreases Incidence of Infections in the Elderly: Effect of Zinc on Generation of Cytokines and Oxidative Stress,” March 2007
Many older adults are deficient in zinc, a trace mineral that plays an important role in maintaining healthy immune function. In this study, ASN member Ananda S. Prasad, et al. conducted a randomized, double-blind, placebo-controlled trial to determine the effect of zinc supplementation on the incidence of total infections among healthy older adults.
Fifty men and women aged 55 to 87 years were recruited for this study from a senior center. The baseline plasma zinc concentrations among the participants were low, suggesting that a marginal zinc deficiency was present throughout the group.
“Our study showed that zinc supplementation administered to the elderly population resulted in a significant decrease in the incidence of infection.”
The zinc-supplemented group received 45 milligrams orally every day for a period of 12 months. At the conclusion of the study, the authors found “the incidence of infections was significantly lower, plasma zinc was significantly higher, and generation of tumor necrosis factor α and oxidative stress markers was significantly lower in the zinc-supplemented group than in the placebo group.” Among the zinc-supplemented group, there were seven incidences of infection over the course of a year compared to 35 infections among the placebo group.
The authors noted that “the limitation of the current study is that the number of subjects in the trial was small. We hope that our results will stimulate larger zinc trials in the elderly.”
Current Developments in Nutrition “Intakes of Vitamin A and Zinc and Markers of Oxidative Stress in Newly Diagnosed HIV-positive Participants in the MASH Cohort in Miami,” June 2019
HIV infection is characterized by increased oxidative stress. In this study, ASN member Priscilla Clayton et al. examined the association of the intake of vitamin A and zinc, both antioxidants, with measures of oxidative stress and HIV disease progression among newly diagnosed HIV-infected patients.
“Antioxidant supplementation may be beneficial immediately after receiving a diagnosis of HIV infection as well as during antiretroviral treatment.”
To conduct their research, the authors developed and implemented a cross-sectional study of 52 HIV patients. Blood was drawn for parameters of oxidative stress and disease stage. Intakes of vitamin A and Zinc were calculated with the use of 24-hour dietary recalls.
The authors discovered that a lower intake of vitamin A and zinc was associated with higher oxidative stress and higher HIV viral load. “These findings suggest that antioxidant supplementation may be beneficial immediately after receiving a diagnosis of HIV infection as well as during antiretroviral treatment.”