HIV and AIDS
Thousands of research studies have demonstrated the positive effect that antioxidants have in managing immune suppression. The Life Extension Foundation was the first organization (in 1985) to propose that the decline in the immune function of persons with HIV may be prevented or slowed by taking high-potency antioxidant supplements. According to Marianna Baum, Ph.D., from the University of Miami Medical School: "Multiple nutritional abnormalities occur relatively early in the course of HIV infection and appear to facilitate disease progression" (Baum 1992).
Low levels of antioxidants and micronutrients in AIDS are most often related to low intake, as well as to malabsorption resulting from diarrhea, and also to metabolic problems and AIDS wasting.
There are causes of immune suppression that have been proven to create a malabsorption syndrome in the gastrointestional tract (e.g., diarrhea, metabolic conditions, AIDS wasting, and drug therapies) (see also the section on Other Causes of Immune Suppression). Malabsorption syndrome is a significant component in the vicious cycle of immune suppression because it can be considered to be both a cause and an effect of immune suppression. Therefore not being able to utilize ingested foods and nutrients can be a specific cause of malnutrition in immune-suppressed patients. It is essential to break the cycle of malabsorption, antioxidant depletion, oxidative stress, immunosuppression, and the resulting increase in malabsorption. It is helpful to remember that the majority of immune system components and their activity is located in the gastrointestinal tract. Immune system activity has a particularly dominant influence in the mucosal lining since the mucosal lining is the area of the body that must assimilate material entering the gastrointestinal tract from the environment.
In addition to its important role in the mediation of oxidative stress and free-radical damage, the amino acid glutamine also plays a major role in the overall health and well-being of the gastrointestinal tract and its supportive organs (stomach, small and large intestine, liver, pancreas, and gall bladder). Glutamine is vital to the function of intestinal cells called enterocytes. Enterocytes are located in the fingerlike projections of the mucosal villi. These cells make up the mucosal lining of the small intestines and are some of the most rapidly dividing cells in the body. They have high energy requirements. Glutamine is the primary nutrient for enterocytes. Enterocyte cells break down glutamine to form glutamate, which is then converted to ATP and used as the energy supply for the cells. Studies have confirmed that glucose (sugar) is not utilized as a fuel source for the intestine (Newsholme et al. 1985; Souba et al. 1985; Hartmann et al. 1989; Alverdy 1990).
Lactoferrin is a subfraction of whey protein that has been found to both directly and indirectly inhibit several viruses that cause disease in humans. It directly inhibits viruses by binding to viral receptor sites, thus preventing the virus from infecting healthy cells. In vitro studies have found that lactoferrin strongly binds to the V3 loop of the gp120 receptor on HIV-1 and HIV-2, resulting in inhibition of virus-cell fusion and entry of the virus into cells (Swart et al. 1998). In addition, lactoferrin indirectly kills or inhibits viruses by augmenting the systemic immune response to a viral invasion. It is interesting to note that there is a systemic deficiency of lactoferrin in persons with HIV. One study that examined 22 asymptomatic and 45 symptomatic patients with HIV compared to 30 healthy controls found that "levels of plasma lactoferrin are decreased in HIV-1 infected patients in relation to the progression of the disease" (Defer et al. 1995). Another study found that the lack of lactoferrin (and secretory Iga) found in the oral cavities of people with HIV correlated strongly with the frequent infections in those areas often seen in patients with AIDS (Muller et al. 1992). Lactoferrin was also found to have "potent" antiviral effects against the replication of both human HIV and cytomegalovirus (CMV) in several in vitro studies with no cytopathic effects on healthy cells.