So where do these free radicals in our bodies come from? Just the simple act of breathing results in the production of free radicals. During respiration, some electrons leak away from the normal respiratory pathway during electron transport. These electrons latch on to free oxygen molecules, resulting in the production of free radicals. Under normal conditions, approximately 1% to 3% of oxygen molecules are converted into free radicals. The air that we breathe is polluted with toxins, which can increase free radical production during respiration. Other environmental factors such as alcohol, cigarette smoking and radiation can also lead to an increase in free radical formation.
In some cases, our bodies actually produce free radicals on purpose. For example, the body's immune system purposely creates free radicals to destroy unwelcome organisms, such as infections. The problem for people with HIV is that excess free radicals create a breeding ground for HIV. HIV thrives in an oxidized environment and uses free radicals to replicate.
Fortunately, our bodies have a defense system to protect our cells from oxidative damage. Antioxidants, which are manufactured within our body or extracted from the food we eat, help neutralize the free radicals in our bodies. The term antioxidant means "against oxidation." Antioxidants work by giving up one of their electrons to free radicals, but unlike free radicals, antioxidants do not become harmful and reactive when they lose an electron. Unfortunately, the normal antioxidant defense system is compromised in people with HIV and antioxidant levels decrease as the disease progresses.
In order to protect and repair the cells in your body, it is important to make sure you are getting enough antioxidants through the food you eat and/or nutritional supplements. The most studied antioxidants are vitamin C, vitamin E, beta-carotene and selenium. Vitamin C, which is a water-soluble vitamin, cannot be stored in the body, so it is important to get some regularly in your diet. Sources of vitamin C include citrus fruits, green peppers, broccoli, green leafy vegetables and strawberries. Vitamin E is a fat-soluble vitamin, which means that it can be stored in the liver and other tissues of the body. Sources of vitamin E include wheat germ, nuts, seeds, whole grains and green leafy vegetables. Beta-carotene, which is converted to vitamin A in the body, is a scavenger of a particular type of free radical and has been found to decrease free-radical damage associated with HIV. Food sources of beta-carotene include green leafy vegetables, carrots and other yellow and orange fruits and vegetables. Selenium is a trace element with antioxidant properties. A selenium deficiency is associated with immune dysfunction and decreased CD4+ counts. Food sources of selenium include seafood, brazil nuts, eggs, meats and whole grains.
It is important to get as many antioxidants as you can from the foods you eat by choosing a well-balanced diet including whole grains, lean meats and 5 to 10 servings of fruits and vegetables everyday. Since people with HIV have a higher need for vitamins, minerals and antioxidants, a supplement regimen may be beneficial, including a multivitamin/mineral supplement (without extra iron) with antioxidants and trace elements. Other antioxidant supplements that are gaining popularity among people with HIV are alpha-lipoic acid, N-acetyl-cysteine, coenzyme Q-10 and pomegranate juice. Megadosing on supplements can be dangerous, so it is important to discuss your supplement regimen with your doctor or dietitian.
There are many different types of antioxidants, including vitamins (C, E, beta-carotene), elements (selenium), amino acids (N-acetyl-cysteine, alphalipoic acid), herbs (green tea) and phytochemicals (flavanoids, polyphenols, allyl sulfides). It is important to find a regimen that meets your individual needs. You also need to reevaluate your food and supplement intake as your health status changes. It is important to do research and/or consult with a dietitian or other health care professional before starting a supplement regimen.
If you are eating all of your fruits and vegetables and taking your multivitamin, you may be wondering if the cells in your body are healthy and benefiting from the antioxidants. Unfortunately, it is not very convenient for you to extract a sample of your cells and slide them under a microscope at a moment's notice, but you can get a good overall picture of the health of your cells by getting a bioelectrical impedance analysis (BIA) test. A BIA is a simple test that measures lean muscle mass, fat mass and fluid levels in your body. A BIA can also measure cell capacitance. Cell capacitance is a measure of the integrity of your cell walls. A low cell capacitance (unhealthy cell walls) is associated with oxidative stress and can be an indication of poor health and/or disease progression. A high cell capacitance (healthy cell walls) is associated with adequate antioxidant support and can be an indication of good health.
For more information on optimizing your antioxidant intake through food and supplements and/or BIA testing, contact AIDS Treatment Initiatives (ATI) at (404) 659-2437.
Michele Bahns, M.S., R.D., L.D., is a dietitian at AIDS Treatment Initiatives (ATI).