Nutrition and HIV management

Why is good nutrition important in HIV?

• Good nutrition helps keep your immune system strong, enabling you to better fight disease. A healthy diet improves quality of life.
• Weight loss, wasting, and malnutrition continue to be common problems in HIV, despite more effective antiretroviral medications, and can contribute to HIV disease progression.
• Good nutrition helps the body process the many medications taken by people with HIV.
• Diet (and exercise) may help with symptoms such as diarrhea, nausea, and fatigue, and with fat redistribution and metabolic abnormalities such as high blood sugar, cholesterol, and triglycerides.
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.

How Food Enhances and Depletes Effectiveness of Medication

Food can enhance or inhibit the absorption, metabolism, distribution and excretion of medication. Sometimes it is a matter of when the food is eaten, other times it is the content of the food itself. For example, food reduces the absorption of the antibiotic Isoniazid (INH) and Rifampin, both medications used to treat tuberculosis (TB), a common opportunistic infection. Because drug absorption is reduced by the intake of food, it is recommended that both INH and Rifampin be taken at least one hour before or two hours after a meal.

The type of food can also influence the effectiveness of a drug. A meal with high fat content (i.e., more than 40 g of fat or three tablespoons of margarine or oil), decreases absorption of the protease inhibitor indinavir (Crixivan), which is best taken without food or with a light meal. The opposite can also be the case: absorption of the ARV drug, tenofavir (Viread), is increased when taken with a high fat meal.

Dietary supplements, including herbal remedies and traditional medicines, also have the potential for both adverse and beneficial interactions with therapeutic drugs. Long-term use of garlic, for example, has been found to reduce the efficacy of the protease inhibitor saquinavir (Invirase). Adverse, even deadly effects of caffeine and ergotamine used as herbal treatment for migraines, have been found in people taking the following protease inhibitors: indinavir (Crixivan), nelfinavir (Viracept), ritonavir/lopinavir (Norvir) and saquinavir (Invirase). St. John’s Wort, a common herbal anti-depressant, reduces the effectiveness of several protease inhibitors such as saquinavir, indinavir, lopinavir, nelfinavir and ritonavir.

How Medication Affects Nutrient Effectiveness

Independent of ARV drugs, HIV infection has metabolic consequences such as weight loss, which, especially if it is lean tissue or muscle loss, can be a strong predictor of death. In combination with the right ARV drugs, food can help to maintain weight or improve weight gain.

A common manifestation of nutrient metabolism changes due to ART, especially protease inhibitors, are changes to lipid or fat metabolism and storage called lipodystrophy. A lipodystrophy syndrome, or fat maldistribution, characterized by either fat accumulation (e.g., breasts, upper back, visceral fat) or fat loss (e.g., face, extremities) can be difficult to manage.

Depending on the ARV drug, patients may experience changes in the type of body fat or lipid, as well as elevated levels of triglycerides and blood cholesterol. Some protease inhibitors, such as indinavir, may affect glucose or sugar metabolism, resulting in insulin resistance and diabetes.

TB provides an example of an opportunistic infection that affects 30 percent of HIV-infected people in resource-limited settings. As food reduces the absorption of the antibiotic, isoniazid, the medication also inhibits the metabolism of a key vitamin, B6 (pyridoxine), which helps to metabolize fats and proteins. The TB medication Rifampin may alter vitamin D metabolism, resulting in weakened bones or osteoporosis. Therefore, depending on which antibiotic is used, vitamin B6 or vitamin D supplements are recommended.

In addition to direct interactions between nutrient and drug metabolism, ARVs may also have side effects that influence food intake and nutrient absorption. Taste changes, loss of appetite, nausea, bloating, heartburn, constipation, vomiting and diarrhea will affect nutritional status simply by causing a reduction in food intake. Reduced food intake and poor nutrient absorption can lead to weight loss and continuing impairment of the immune system, which, in turn, allows HIV to progress more rapidly to AIDS.

Many of these ARV therapy side effects are similar to certain AIDS-related symptoms and call for similar dietary management.

• Changes in taste. The protease inhibitors, saquinavir and ritonavir, may cause food to taste metallic, sweeter, more sour, or too salty, resulting in a decrease of food intake. Flavor enhancers such as salt, sugar, spices, vinegar or lemon can stimulate the taste buds, increase taste acuity, and mask unpleasant flavors. Adding simple foods like onions to soup will boost flavor and can help to improve intake.

• Anorexia. Several medications, such as the TB drug isoniazid and the non-nucleoside reverse transcriptase inhibitor (NNRTI) ARVs, lamivudine (Epivir) and stavudine (Zerit), may cause a loss of appetite, leading to reduced food intake and anorexia. Dietary management requires eating small and frequent meals that include favorite foods. It is also important to maintain as much physical activity as possible, such as walking in fresh air, which also helps to stimulate appetite.

• Vitamin depletion. As noted above, some ARVs have been associated with loss of vitamin D and increased risk of osteoporosis and arthritis, both of which require medical and dietary responses. Because vitamin depletion is a common condition in resource-limited settings, side effects of treatment are often difficult to link to a specific medication. A balanced diet containing high calcium foods, such as milk, yogurt, cheese and vitamin D supplement are recommended.

Maximizing the Benefits of Both Medications and Food

The major challenge facing practitioners in resource limited settings is to devise a treatment regimen with the right combination of ARV therapy and diet that both improves overall nutrition and maximizes the drug effectiveness. A drug protocol, which identifies specific interactions, includes making the right food choices, and monitoring adherence needs.

In resource-poor settings, inadequate or non-existent laboratory facilities to monitor ARV regimens and possible food interactions make the use of basic approaches to nutritional assessment and counseling essential. Screening and monitoring clients using mid-upper-arm circumference, and weight and height can determine the degree of wasting in both children and adults. It also will help ensure an understanding of the effects of the protocol. Information and support to clients should be a central part of the regimen, helping them to maintain a healthy weight by eating a variety of nutritious foods, reducing intake of refined sugar and excessive carbohydrates, increasing fiber intake, avoiding alcoholic beverages, caffeine and smoking, and exercising regularly.

Still, many metabolic changes are not well understood, making it difficult to establish satisfactory management solutions. Cholesterol lowering drugs (such as the statins), for example, interact both positively and negatively with ARV drugs. In addition, it is unlikely that they will become widely available in resource-limited settings in the near future.

General advice for those taking ARVs to help manage metabolic changes can be most useful. Reasonable approaches include diet and exercise modification, judicious use of medications, and adjustments in the ARV regimen as required. In the case of diabetes, a specific carbohydrate-controlled diet, reduced intake of refined sugar and saturated fat, exercise and anti-diabetic medications are recommended.

For pregnant and lactating women, where there is still a lack of sufficient research, the principles of sound clinical and nutritional assessment and monitoring combined with the available treatment options apply. The same principles apply in designing a dietary response to include food and nutrient choices appropriate to the person, adequate, accessible, palatable and balanced.

So much is yet unknown about these ARV-food interactions and their effects, especially in different settings and in populations where malnutrition is endemic. If ARV therapy is to deliver the promise of treating large numbers of HIV infected people who, until now, have been unable to access potentially life-saving treatments, health workers, clinicians and researchers must document, monitor, continue to investigate, cooperate and share information in the ongoing dynamic process of better understanding and management of HIV/AIDS.