|Nutrition and HIV/AIDS United Nations Administrative Committee on Coordination, Sub-Committee on Nutrition. Nutrition Policy Paper #20. Report of the 28th Session Symposium Held 3-4 April 2001, Nairobi, Kenya (UNAIDS - UNSSCN, 2001, 85 p.)|
(excerpted from Piwoz EG and Preble EA (2000) HIV/AIDS and Nutrition: A review of the literature and recommendations for nutritional care and support in Sub-Saharan Africa. SARA Project, Academy for Educational Development: Washington DC)
The effect of HIV/AIDS on nutrition
HIV/AIDS affects nutrition in these ways:
· Reductions in food intake - Reductions in food intake may be due to painful sores in the mouth, pharynx, and/or esophagus. Fatigue, depression, changes in mental state (sometimes due to specific nutrient deficiencies), and other psychosocial factors may also play a role by affecting a persons appetite and interest in food. Economic factors affect food availability and the nutritional quality of the diet. Side effects from medications - including nausea, vomiting, metallic taste, diarrhea, abdominal cramps and anorexia - also result in lower dietary intakes.
· Nutrient malabsorption - Nutrient malabsorption accompanies frequent bouts of diarrhea commonly experienced by people with HIV/AIDS. In addition, some HIV-infected people have increased intestinal permeability and other gut defects, even when asymptomatic, that contribute to nutrient malabsorption1. It is believed that HIV infection of the intestinal cells may also cause epithelial damage and nutrient malabsorption. Malabsorption of fats and carbohydrates is common at all stages of HIV infection in adults and children. Fat malabsorption, in turn affects the absorption and utilization of fat-soluble vitamins further compromising both nutrition and immune status.
· Metabolic alterations - Changes in metabolism may occur as a result of severely reduced food intake as well as from the immune systems response to HIV infection. Anorexia, fever, and the break down of muscle frequently accompany this response. When the body responds to invading pathogens, it releases pro-oxidant cytokines and other reactive oxygen species. This leads to the increased utilization of anti-oxidant vitamins (vitamins A, E, C and beta-carotene) as well as utilization of several minerals that form antioxidant enzymes (such as zinc and selenium). Oxidative stress occurs when there is an imbalance between the pro-oxidants and anti-oxidants, causing further damage to cells, proteins, and enzymes. Oxidative stress is believed to increase HIV replication and transcription, leading to higher viral loads and disease progression.
· Increased energy and protein requirements - The bodys cytokine-mediated reactions to infection adversely affect metabolism. The result is an increase in energy and protein requirements of people living with HIV and AIDS. This increase ranges from about 10-15% for energy requirements among asymptomatic HIV-infected persons, to up to 50% for protein requirements2. This translates roughly into an additional 300 kcals and 25 g of protein per day, which could be met through snacks or an extra serving of the family meal.
In summary, the impact of HIV/AIDS on nutrition results in weight loss and the wasting that is common in people living with AIDS. During the early stages of HIV infection, weight loss is mainly associated with reduced dietary intake and secondary infections, particularly diarrhoea3. This weight loss may be addressed, and even reversed, by nutritional or dietary management. However, once the metabolic abnormalities begin to play a leading role, it becomes very difficult, perhaps impossible, to reverse the nutritional consequences of the disease.
The effect of nutritional status on HIV disease progression
Studies from both industrialized and developing countries have shown that HIV-infected individuals have decreased absorption, excessive urinary losses and low blood concentrations of vitamins A, B1, B2, B6, B12, C, E as well as folate, beta-carotene, selenium, zinc and magnesium4,5. It is not known whether these deficiencies are independent markers of disease progression resulting from a compromised immune system, or whether they are causally related to HIV disease progression and mortality. This distinction is important in order to determine whether the nutritional deficiencies can be reversed, and whether nutritional therapy and management can slow or alter the course of disease. Randomized, controlled trials are required in order to assess a causal relationship between these nutritional observations and HIV outcomes. Relatively few such trials have been carried out.
The body of literature reporting on trials in Africa (mostly of vitamin A) and in industrialized countries (on vitamin B12, E, selenium and zinc) suggests that nutritional status affects HIV-related disease progression and mortality, and that improving nutrition status may improve some HIV-related outcomes. Current understanding of the potential impact of nutritional interventions is incomplete and there are issues to consider when extrapolating findings from research undertaken in North America and Europe to populations where malnutrition is widespread.
1. Keating J, Bjarnason I, Somasundaram S, et al (1995) Intestinal absorptive capacity, intestinal permeability, and jejunal histology in HIV and their relation to diarrhea. Gut 37: 623-629.
2. Woods MN (1999) Dietary recommendations for the HIV/AIDS patient. In: Nutritional Aspects of HIV Infection. Miller TI and Gorbach SL (eds). Oxford University Press: New York.
3. Macallan DC (1999) Dietary intake and weight loss patterns in HIV infection. In: Nutritional aspects of HIV Infection. Miller TI and Gorbach SL (eds). Oxford University Press: New York.
4. Friis H and Michaelsen KF (1998) Micronutrients and HIV infection: a review. European Journal of Clinical Nutrition 52: 157-163.
5. Tang AM and Smit E (1998) Selected vitamins in HIV infections: a review. AIDS Patient Care and STDs 12: 263-273.
What does this mean for programmes?
Providing early and adequate nutrition support and care may be one of the most important interventions for people with HIV, to:
· maintain and build body stores of energy, protein and anti-oxidant nutrients
· prevent diarrhea by promoting hygiene and food safety
· minimize the nutritional impact of secondary infections when they occur
· improve the quality of life and prolong independence.
In addition - the nutrition community can take these first steps to help national health officials and policy makers meet the broader challenges associated with HIV/AIDS:
· Strengthen the involvement of persons living with HIV/AIDS in policy and program interventions to prevent transmission and control the epidemic.
· Promote Government commitment to address food security and nutrition problems for all persons infected and affected by the epidemic.
· Support and encourage community-based care.
· Develop, test and disseminate practical guidelines for health workers and community volunteers on nutrition care and support for persons living with HIV. Materials developed should be culturally acceptable, and feasible. Involve people living with HIV in the development process.
· Promote and mainstream voluntary counseling and testing services.
· Place the commitment to fight HIV/AIDS at the center of the national capacity building agenda.
· Tailor and share information that will empower and enable politicians, policy makers, program mangers and service providers to mobilize partnerships for HIV/AIDS prevention and control.