Diet, Nutrition & HIV

Good nutrition is key to a healthy lifestyle, regardless of whether one is living with HIV/AIDS. Optimal nutrition can help boost immune function, maximize the effectiveness of antiretroviral therapy, reduce the risk of chronic illnesses such as diabetes and cardiovascular disease, and contribute to a better overall quality of life.

In the early years of the AIDS epidemic, many people with HIV were dealing with wasting and opportunistic infections (OIs) linked to unsafe food or water. While these problems are less common today in developed countries with widespread access to highly active antiretroviral therapy (HAART), many HIV positive people have traded these concerns for worries about body shape changes, elevated blood lipids, and other metabolic complications associated with antiretroviral therapy.

Fortunately, maintaining a healthy diet can help address these problems. As HIV positive people live longer thanks to effective treatment, good nutrition can also help prevent problems (such as bone loss) associated with normal aging. But there is no single, optimal eating regimen appropriate for every person living with HIV/AIDS. Instead, HIV positive people should adopt a sensible balanced diet and consult an experienced nutrition specialist for individualized recommendations.


Food for Life
Food is essential for life, providing the fuel the body needs to function and the building blocks that make up cells, tissues, and organs. The energy provided by food is expressed in terms of calories. The body requires a certain number of calories simply to carry out its basic metabolic functions such as respiration and maintenance of body temperature. Additional calories are needed to support physical activity, fight infection, and rebuild damaged tissues.

If a person does not take in enough calories, fat is broken down to provide fuel. Once the fat is consumed -- or if an individual's metabolism is disrupted due to illness -- lean body mass (muscles and organs) is then used for fuel and raw materials. Conversely, if a person takes in more calories than needed, the extra energy will be stored as fat. The average person needs about 10-20 calories per pound (depending on physical activity level and other factors) to maintain a stable body weight; this requirement is likely to be higher for people with HIV, especially those with advanced disease.

But all food is not equal. While all contain calories, different foods vary widely in the nutrients they provide. A balanced diet is comprised of the following components.

Protein: Protein provides the building blocks of lean body mass. When a protein-rich food is consumed, it is broken down into amino acids, which are reassembled to create enzymes, hormones, and bodily tissues. Most nutrition experts recommend that protein should contribute about 15-20% of the total calories in a person's diet. Good sources include meat, poultry, fish, eggs, dairy products, tofu, nuts, and legumes (e.g., dried beans, lentils).

Carbohydrates: Carbohydrates, which are converted to glucose in the body, are a primary source of energy. Carbohydrates are classified as simple or complex; complex carbohydrates take more time to break down, and thus provide fuel over a longer period of time. Despite the recent popularity of "low carb" diets, most nutrition experts recommend that carbohydrates -- primarily complex ones -- should make up at least 50% of one's total daily calorie intake. Simple carbohydrates are found in processed sugar, honey, fruit and juice, and lactose (milk sugar). Complex carbohydrates are found in grain products such as bread, pasta, and rice; legumes; and starchy foods such as corn, potatoes, winter squash, and root vegetables.

Fats: Fat in food is a source of energy and has a high concentration of calories. Excess energy from any source -- not just fatty food -- is converted to fat in the body and stored for later use. Cholesterol (found in animal products like meat and eggs) and triglycerides are present in food, but are also produced when the body metabolizes sugar and saturated fat. Everyone needs some dietary fat, but getting too little is rarely a problem. More important is the type of fat. Saturated fats promote elevated blood levels of low-density lipoprotein (LDL) "bad" cholesterol, which can clog arteries and increase the risk of cardiovascular disease. Saturated fat is found in meat, butter, tropical oils (e.g., coconut, palm), and "trans" fats or hydrogenated oils (which are chemically altered to make them solid at room temperature). Polyunsaturated fats (found in safflower, sunflower, corn, and soybean oils) are generally considered more healthful, and monounsaturated fats (found in olive and canola oils, nuts, seeds, and avocados) can help raise levels of high-density lipoprotein (HDL) "good" cholesterol, which protects against heart disease. A balanced diet also contains essentially fatty acids, including omega-3 (found in flax and cold-water fish). Most experts say fats should make up no more than 25-30% of total calorie intake, with less than 10% being saturated fat.

Fiber: Also known as "roughage," fiber is indigestible plant matter such as cellulose. Insoluble fiber plays an important role in digestion, helping food move smoothly through the colon (large intestine); this type of fiber is found in the skin and pulp of many fruits and vegetables, whole grains, popcorn, and seeds. Soluble fiber helps stabilize blood sugar and may reduce LDL cholesterol levels; this type of fiber is found in oatmeal and oat bran, legumes, nuts, and fruits such as apples, oranges, pears, and grapes.

Vitamins and minerals: Along with the "macronutrients" described above, a balanced diet also contains many "micronutrients," organic and inorganic substances necessary for proper biological functioning. Water-soluble vitamins (B and C) are excreted in the urine and must be consumed more often; fat-soluble vitamins (A, D, E, and K) are stored in the liver and can reach toxic levels if taken in large doses. Most vitamins must be obtained from food, although the body manufactures vitamin D when the skin is exposed to sunlight and others are produced by bacteria in the gut. Minerals (including the electrolytes chloride, potassium, and sodium) are inorganic substances found in the environment. The body needs several trace elements in tiny amounts, including boron, chromium, cobalt, copper, iodine, manganese, molybdenum, selenium, and zinc. Cooking and processing can destroy some vitamins and minerals. For information on the function and food sources of specific vitamins and minerals, see the chart below.

Antioxidants: Free radicals are unstable oxygen molecules that contain unpaired electrons. This allows them to set off damaging chain reactions when they bind with and "steal" electrons from other molecules in the body -- a process known as oxidative stress. Antioxidants scavenge and neutralize free radicals. By disrupting the oxidation process, antioxidants help protect cells from damage. Antioxidants include vitamins C and E, beta-carotene, the minerals selenium and zinc, and glutathione.

Phytochemicals: Among the advantages of obtaining nutrients from a balanced diet rather than supplements is that there are substances in whole foods that may offer unrecognized benefits. While most vitamins and minerals were isolated early in the 20th century, plant compound called phytochemicals are just now being discovered. Among these are allyl sulfides (found in garlic and onions), anthocyanins (in blueberries and blackberries), carotenoids (including beta-carotene in orange fruits and vegetables, lycopene in tomatoes, and lutein in dark green leafy vegetables), catechins (the tannins in green and black tea), flavonoids (in dark chocolate, red wine, tea, and many fruits), isothiocyanates (in broccoli and other cruciferous vegetables), limonoids (in citrus fruits), and sulforaphane (also in cruciferous vegetables). Some phytochemicals work as antioxidants, but others appear to have different mechanisms of action.


How HIV Impacts Nutrition ... and Vice Versa
In the early years of the epidemic, healthcare providers soon learned that people with AIDS commonly experienced both overt protein/calorie malnutrition and deficiencies of specific nutrients. But nutrient depletion may also begin to occur earlier in the course of HIV disease, even among individuals with relatively intact immune systems. Several factors can contribute to nutritional problems in people with HIV/AIDS.

Malabsorption: HIV or associated infections can damage the lining of the gastrointestinal tract, which can interfere with absorption of nutrients. Some HIV positive people experience specific problems, such as fat malabsorption, which can impair absorption of fat-soluble vitamins.

Opportunistic infections: Various bacterial, viral, fungal, and parasitic infections can interfere with proper nutrition. Malignancies (cancers) and mycobacterial illnesses such as tuberculosis are often characterized by wasting. Several OIs cause vomiting and diarrhea, which can lead to poor absorption or loss of nutrients. Other infections -- such as thrush (oral candidiasis), gingivitis (gum inflammation), and cytomegalovirus esophagitis (throat inflammation) -- can make eating painful.

Medications: Antiretrovirals, OI drugs, and other medications can contribute to nutrient deficiencies and imbalances, either due to direct drug-nutrient interactions or drug side effects. Vomiting and diarrhea can lead to dehydration and depletion of nutrients. Loss of appetite (anorexia), fatigue, and taste alterations can make it difficult to eat enough. Antibiotics may interfere with nutrition by killing off beneficial bacteria in the gut. Food requirements -- the need to take medications either on a full or an empty stomach or with specific types of food -- can disrupt normal eating patterns. Finally, some antiretroviral medications are associated with metabolic changes such as blood lipid and glucose abnormalities.

Inadequate intake: Ill people often experience anorexia. OI symptoms and medication side effects -- nausea, diarrhea, sore mouth or throat, altered sense of taste or smell -- can further reduce the desire or ability to eat. This may be compounded by lack of money, depression, or feeling too fatigued to shop and prepare food.

Altered nutritional requirements: By altering metabolism (how the body processes and uses nutrients), acute or chronic illness -- including HIV disease and OIs -- and the resulting immune response can increase the body's energy needs. People with HIV/AIDS may require more calories, macronutrients, and specific vitamins and minerals. Chronic illness may also alter hormone and cytokine levels, which may have nutritional implications.

Conversely, nutritional deficiencies can impair immune function, potentially worsening HIV disease progression. Research has shown that depletion of vitamins A, C, and E, the B-complex vitamins, and the minerals selenium and zinc can interfere with cell-mediated immunity (CD4 cell, natural killer cell, and neutrophil proliferation and activation), antibody production, and normal cytokine signaling.

Studies looking at the prevalence of nutritional deficiencies in people with HIV/AIDS have produced conflicting data, but on the whole, depletion of nutrients (e.g., vitamins A and E, and minerals including magnesium, selenium, and zinc) appears to be common, especially among individuals with advanced disease. In particular, having HIV seems to decrease the body's store of antioxidants, as they are needed to offset increased oxidative stress. Researchers have uncovered evidence of subtle nutritional deficiencies among people who appear to be eating an adequate diet and are not suffering from frank protein/calorie malnutrition.

Experts don't yet understand the clinical significance -- if any -- of subtle changes in laboratory values relative to the norms seen in the HIV negative population, nor do they know how much of any given nutrient people with HIV/AIDS need for optimal immune function and overall health. Due to a lack of research on nutritional status in the setting of HIV disease, and because nutritional requirements vary dramatically from person to person, there are few definitive recommendations for nutritional supplementation in the HIV positive population.


Waste Not, Want Not
Wasting -- also known as cachexia -- was a prominent feature of AIDS in the early years of the epidemic; even today, AIDS is referred to as "slim disease" in Africa. Experts define wasting as involuntary or unwanted loss of 10% or more of body weight. As Steven Grinspoon, MD, and Kathleen Mulligan, MD, discuss in an April 2003 special issue of Clinical Infectious Diseases (CID) devoted to nutrition and HIV, "wasting ... has been associated with increased mortality, accelerated disease progression, loss of muscle protein mass, and impairment of strength and functional status." Even a 5% loss has been linked to increased illness and death.

In classic HIV-related wasting, lost weight is in the form of lean body mass rather than fat, especially in men. People with HIV/AIDS (and other chronic illnesses) require more calories simply to maintain their weight, due to increased metabolism, higher energy demands, hormone and cytokine imbalances, inefficient absorption and utilization of nutrients, and/or accelerated tissue breakdown (catabolism).

While effective antiretroviral therapy has dramatically reduced the incidence of severe wasting, moderate weight loss is still a prominent feature of HIV disease. For example, as reported in the September 1, 2005 Journal of Acquired Immune Deficiency Syndromes (JAIDS), Alice Tang, MD, from Tufts University Medical School and colleagues found a steady increase in the rate of 5% or greater loss of body weight between 1995-1997 (pre-HAART) and 1998-2003 (HAART era). In an analysis of 713 HIV positive participants in the Nutrition for Healthy Living cohort, 53% lost at least 5% of their body weight during any six-month period. Weight loss was significantly associated with nausea, diarrhea, thrush, poverty, history of drug use, CD4 cell count below 200 cells/mm3, and HIV viral load above 100,000 copies/mL. The authors were unable to pinpoint the reasons for the increased rate of wasting in the HAART era.

In another study (reported in the October 15, 2005 issue of CID), Adriana Campa, PhD, from Florida International University and colleagues found that 17.6% of 119 HIV positive, mostly homeless drugs users in Miami showed evidence of HIV-related wasting. In this study, wasting was associated with cocaine and heavy alcohol use, "food insecurity" (not eating for one or more days in the past month), and higher HIV viral load. Participants taking HAART were more likely to experiencing wasting than those not receiving anti-HIV treatment (86% vs 67%).

Rather than dramatic whole-body weight loss, today many HIV positive people on HAART experience lipoatrophy, or fat loss in the face, limbs, and buttocks. Paradoxically, this may coincide with fat accumulation in other areas of the body (discussed below). Lipoatrophy is most strongly associated with use of nucleoside reverse transcriptase inhibitors (NRTIs), especially d4T (stavudine or Zerit). For this reason, U.S. government treatment guidelines no longer recommend d4T as part of a first-line regimen for people starting HAART.

Since HIV positive people and their clinicians may not recognize the early signs of wasting, it is important to monitor weight regularly to detect subtle changes. Underlying factors contributing to weight loss -- such as OIs or hormone imbalances -- should be promptly addressed. But, as Grinspoon and Mulligan point out, "no therapeutic guidelines currently exist for the management of weight loss and wasting in HIV-infected patients."

When it comes to weight loss, prevention is often easier than cure. To add calories, focus on proteins and complex carbohydrates rather than "junk food" that contains mostly sugar and fat. Consider eating several small meals and snacks throughout the day rather than two or three large meals. Nutritional supplements such as Ensure or Boost may benefit individuals who find it difficult to eat solid foods. Some cities offer food delivery programs for people with HIV/AIDS who are unable to shop or prepare meals (e.g., Project Open Hand in San Francisco, God's Love We Deliver in New York City, Moveable Feast in Baltimore).

The appetite stimulant megestrol acetate (Megace) tends to promote fat rather than muscle gain and can cause side effects including edema (swelling). Certain antidepressants and other medications may also enhance appetite. Some patients swear by medical cannabis or dronabinol (Marinol), a pill that contains a synthetic version of marijuana's active ingredient, THC.

While recombinant human growth hormone (HGH, Serostim) is FDA-approved for the treatment of HIV-related wasting, it is extremely expensive and can cause side effects including carpal tunnel syndrome, joint pain, and insulin resistance. Anabolic (muscle-building) steroids such as testosterone and oxandrolone (Oxandrin) help some patients gain weight, but can also cause adverse effects. Hormone replacement therapy is most useful for individuals who have low levels; there is little evidence that "supraphysiological" doses (higher than the natural physiological range) are beneficial, and they may be harmful (see "HIV and Hormones" in the Summer 2004 issue of BETA). Research has shown that anabolic steroids work better when combined with resistance exercise; in fact, some studies suggest resistance exercise works better than steroids, without the cost or side effects.
source:www.thebody.com