Effects of nutrition on HIV Disease progression

The links between HIV and nutritional status run both ways. It has long been known that weight loss strongly predicts illness or death among people with HIV. More recently it has been found that this applies even to people taking antiretroviral treatment. Losing as little as 3-5% of body weight significantly increases the risk of death, losing more than 10% is associated with a four- to six-fold greater risk. A Zambian study involving nearly 30,000 patients has shown that failure to gain weight six months after the start of antiretroviral treatment increases the chance of death ten fold when compared with those who gain over 10 kilograms.

Various micro nutrients have been linked to changes in the rate at which HIV infection progresses to AIDS. Low levels of vitamin A, vitamin B12, vitamin E and selenium seem to accelerate progression. The effects of other micro nutrients, however, are more controversial. One such example is zinc. Although zinc is essential for a healthy immune system, it has been shown to play a role in HIV’s replication cycle. 12 On the other hand, some scientists claim zinc delays HIV disease progression.
There is strong evidence that malnourished people are less likely to benefit from antiretroviral treatment. One study in Malawi found that patients with mild malnutrition (a low body weight for their height) were twice as likely to die in the first three months of treatment. For those with severe malnutrition the risk was six times greater than for those of healthy body weight. Researchers in Singapore have reported similar findings. A study in Zambia showed death rates in the first three months of starting antiretroviral treatment were highest (95%) among the most severely malnourished. This is not just an issue for developing countries for example a study of people receiving antiretroviral treatment in Sydney, Australia found that one in three did not have access to nutritious food, and one in five said they regularly went hungry.

Without food or the right nutrition, taking antiretroviral drugs can be so painful that people simply don’t. In a choice between taking pills with no immediate or obvious effect, and eating food to survive, food will almost certainly take priority every time. A health worker in Zimbabwe, where malnutrition is widespread, explained that taking antiretroviral drugs on an empty stomach is like digesting razor blades. The result is that many simply do not take them. In resource-poor countries, treatment in children is made more difficult because many children with HIV are severely malnourished. Very little is known about how best to treat such children and in particular whether it is best to start antiretroviral treatment before or after nutritional rehabilitation. The World Health Organisation recommends treating the malnutrition first, but stresses that “further research on these matters is urgently needed.”

The ways in which the body digests, absorbs and makes use of drugs are very similar to the ways in which it treats food, providing many opportunities for food-drug interactions. As explained later in this article, a number of foods and supplements are known to alter the effects of antiretroviral drugs. It is also possible that some micro nutrient deficiencies may make the drugs less effective, or may worsen side effects.
The chance of someone transmitting HIV is linked to the amount of virus in their bodily fluids, which is known as the viral load. In theory, micro nutrient deficiencies may increase viral load by enabling HIV to replicate faster, or by weakening the immune system. Similarly, someone whose immune system has been weakened by micro nutrient deficiencies may be more likely to acquire HIV. Research in this area has, however, been largely inconclusive. The strongest evidence links low levels of retinol (the animal form of vitamin A) in women’s blood with increased rates of mother-to-child transmission.

Poor nutrition may also affect the spread of HIV in a very different way: by altering sexual behavior. One study of two thousand people in Botswana and Swaziland found that women lacking enough food to eat were less likely to use condoms and more likely to engage in risky activities, such as exchanging sex for money or resources.

Dietary advice should be tailored to individual circumstances. However, in general the recommendations for people living with asymptomatic HIV infection are much the same as for everyone else, meaning a healthy, balanced diet. Only three differences are worth noting:

- Because people with untreated HIV tend to burn more energy, the total number of calories should be around 10% higher than the usual guideline amounts, and up to 30% higher during recovery from illness. The balance of fat, protein and carbohydrates should remain the same.
- Many experts recommend a daily multivitamin (usually without iron, except in menstruating women or people with iron deficiency).
- The World Health Organisation recommends vitamin A supplements every 4-6 months for young children living with HIV in resource-poor settings.

HIV positive people suffering loss of appetite may need to make an extra effort to ensure they are eating enough. Helpful suggestions include eating several small meals per day, taking exercise to stimulate appetite, possibly mashing or liquidizing food to ease swallowing, and seeking advice from a health provider or dietician.

If other approaches have failed to reverse wasting then doctors may recommend a liquid food supplement, an appetite stimulant, or resistance exercise to build muscle. Other possibilities include steroids and hormone treatments, though these can be expensive and have serious side effects.