“We [know] that nutrition is important in the care of HIV-infected adults and children, and we have a little understanding of the science... Now we need to recover the lost time and implement what we already know works,” said Professor Nigel Rollins, of the University of KwaZulu-Natal, South Africa, at the opening ceremony of WHO Technical Consultation on Nutrition & HIV/AIDS in Africa, held on the evening of April 10th.
More than 240 scientists, national representatives, funders, programme planners, NGOs and implementers have gathered for the WHO consultation this week in Durban, South Africa to discuss the role of food and nutrition in HIV & AIDS.
Nutrition neglected
Over the past couple decades, so much attention has been focused on the virology and immunology of HIV & AIDS that the relative contribution of nutrition to the illness has often been overlooked.
At times, nutrition scientists have struggled to be taken seriously. This is partly due to the many charlatans, quacks and pseudoscientists (such as Matthias Rath (see…) who have touted vitamins and micronutrients as cure-alls.
But nutritional research has produced seemingly conflicting or counter-intuitive findings thereby adding to the confusion. Some of this can be blamed on the workings of nutrients in the human body (and with each other) — which are complex and not always well understood. Poorly designed studies (of which there are many) only muddy the picture further.
As a result, few policy makers, clinicians or patients have a clear understanding of the role of nutrition in HIV disease. And even when there is an interest in implementing nutritional interventions, only broad guidance has been available to assist them.
And yet, a growing body of evidence show that nutritional abnormalities and their resulting complications are a common and potentially serious component of HIV disease — especially in a part of the world where pre-existing malnutrition and food insecurity are endemic. In sub-Saharan Africa, especially, food and nutrition issues affect almost every aspect of HIV prevention, infection, care and treatment in adults and children.
In advance of the consultation, the organizers of this WHO consultation performed a comprehensive and rigorous review of all the available published scientific research on the interactions of nutrition with HIV and AIDS. Dr. Rollins chaired this effort and gave a brief overview of its findings during the meeting’s opening plenary. Over the next several days, these data were discussed in much greater detail (and will be covered in be covered in upcoming HIV & AIDS Treatment in Practice).
The effect of HIV & AIDS on energy and protein needs
“ Energy needs increase by about 10% in adults and children from the time of infection, said Dr. Rollins. “During and after severe illnesses, these needs might increase by a further 20-30% in adults and 50% or more in children.”
But other than a balanced diet, there are no clear data to show that people with HIV need to increase the amount of protein they eat. Protein usually makes up 12-15% of the total diet.
After a patient has already lost weight, it may be difficult to recover (or improve their clinical status), simply by improving the diet alone. On the following morning, Dr. Andrew Tomkins, of the Institute of Child Health noted that often when weight is recovered, it often consists of fat, rather than lean body tissue (such as muscle).
These findings argue for a more proactive approach to dietary supplementation in people with HIV.
Micronutrients
Even though, people with HIV often have low levels of micronutrients, “there is insufficient data at present to categorically define the effect of micronutrient supplementation on transmission and disease progression,” said Dr. Rollins.
But some vitamins and micronutrient supplementation has been shown to be important for health, especially in the developing world. For example, Vitamin A supplements reduce diarrhoeal morbidity and mortality especially in young children.
“Adequate intakes of essential vitamins and minerals should be an emphasis of HIV care programmes,” said Dr. Rollins. This is especially true for areas of the world where diets are micronutrient deficient — such as Africa. Many studies that have shown null effect from micronutrient supplementation have been conducted in the US where the diet is high in micronutrients — these data have little application in micronutrient deficient areas.
Infant feeding and HIV transmission
Exclusive breastfeeding is the best way to feed a child, but in areas with a high prevalence of HIV, there are concerns about HIV transmission.
“The risk of HIV transmission is constant (0.74% per month) and cumulative for as long as the child is breastfed,” said Dr. Rollins. Data show that the risk of postnatal transmission is increased with low maternal CD4 count and a high viral load.
However, in much of the developing world, formula feeding is not a practical solution, because supplies of clean drinking water are not reliable. Further, recent reports confirm that formula-feeding part of the time is associated with a higher risk of transmission than exclusive breastfeeding.
The tendency is now to recommend that women in Africa exclusively breastfeed and wean early (by six months). There is ongoing research to see whether giving the mother antiretroviral therapy while she is breastfeeding further reduces the risk of HIV transmission.
Growth abnormalities in HIV-infected children
“Poor growth, especially statural (height) growth, occurs before the onset of opportunistic infections and is significantly associated with the degree of immune deficiency and survival in HIV-infected children, said Dr. Rollins, a paediatrician by training. “The exact mechanisms of wasting in children are complex but insufficient food intake and diarrhoea are major causes of poor growth, especially in resource-poor countries.”
When clinically indicated, antiretroviral therapy has clearly been shown to improve weight, growth and development of infected children.
Pregnant and lactating women
Studies have shown that weight and skinfold thickness in HIV-infected pregnant women decline with increasing viral load and decreasing CD4 count, however, pregnancy and lactation do not in themselves advance HIV disease.
There had been some confusion around this issue, because a few years ago, a sub-analysis of a Kenyan study suggested that mortality was higher among HIV-infected breastfeeding women than among women who formula-fed their infants. However, the study was not really designed to ask this question, and no other study has reported similar findings. In fact, subsequent studies designed to assess this issue have found no difference in mortality between breastfeeding and non-breastfeeding HIV-infected women.
Pregnant and breastfeeding women should continue to take iron and folic acid supplements.
Nutrition and antiretroviral therapy (ART)
“ART can reverse but not always rectify the loss of body mass, including muscle, that occurs in HIV,” continued Dr. Rollins. However, very little research has been conducted to fully understand the relationship between nutrition and ART.
For example:
- Few studies have evaluated the pharmacokinetics (how drugs are absorbed, metabolised distributed in the body) on antiretrovirals in severely malnourished patients
- Does nutrition improve adherence?
- Are there interactions with herbal treatments and other therapies
- Does nutrition affect the development of longer term antiretroviral related complications such as lipodystrophy and bone problems
Programme implications
The review of the available research has number of clear implications for HIV management programmes currently being designed or implemented.
- All adults, children, pregnant and lactating women with HIV infection should be assessed for their nutritional status as part of their routine care. This should include an assessment of their access to adequate and appropriate food
- Programmes need to have mechanisms to actively support adults and children who are found to have inadequate intakes of food or micronutrients
- Poor nutritional in uninfected adults and children (or whose status is unknown) must be similarly addressed. Data show that food insecurity and poor nutritional status is associated with increased risk of infection. Approximately 90% of African do not know their HIV-status, and programmes must ‘cast their nets widely’ to prevent malnutrition and weight loss among these individuals.
Moving forward
Dr. Rollin’s finished the overview by addressing what was needed in order to recover the time lost during which nutrition’s role in HIV and AIDS was not fully recognized.
“We need to be unambiguous regarding the role of nutrition and ART,” he said. “And we need to… implement what we already know works.
To do this, he called upon those present at the consultation to identify and commit to achievable action targets and timelines. “Finally, “ we need to hasten the clinical and operational research agenda,” he concluded.