QUESTION: I understand that antioxidants decrease the number of free radicals in the body. How does one determine the number of free radicals one has?
– Richard Kurylo,
North Park
ANSWER: Free radicals (the kind generated in chemical reactions, not in Berkeley in the '60s) are molecules with unpaired electrons. Electrons like to hang out in pairs, and when they find themselves solitary, they try to break up happy electron couples in other molecules.
DNA, proteins and fats can all be damaged by free radicals, and free radicals have been implicated in a wide range of diseases, including cancer, Alzheimer's disease and heart disease.
Free radicals' bad rap is not entirely fair however. They are produced as a normal part of many chemical reactions in our cells, and they play a number of important roles in the body. For example, free radicals are used by our immune systems as weapons against invading bacteria and viruses.
It is not possible to find out how many free radicals one has. Tests for free radicals are not used by doctors because the complexity of various body tissues makes these tests impractical, according to Dr. Joseph Scherger, a professor in Department of Family and Preventive Medicine at UCSD's School of Medicine.
Scherger points out that although elevated levels of free radicals cannot be measured directly, their effects can be measured. For example, free radicals can cause inflammation in the blood vessels, which leads to atherosclerosis, or clogging of the arteries. Inflammation increases the amount of a chemical in the blood called C-reactive protein (CRP). So levels of CRP provide indirect information about free radical activity.
Someday, it might be possible to have a scan for free radical activity in a particular organ or tissue. Electron spin resonance – a measurement technique that detects free radicals based on how they behave in a magnetic field – has been used to detect free radicals in small animals.
However, several challenges to extending this technique to humans exist. For instance, it involves administering chemicals that are unsafe to humans to trap the radicals so they can be measured. It might be difficult to draw conclusions from a free radical test, since levels of free radicals are dynamic. Elevated free radicals might be a sign of a chronic problem or the normal response of your body to a temporary infection.
Doctors say the best way to keep a balance between free radicals and antioxidants is avoid smoking, minimize intake of trans fats and keep your diet rich in fruits and vegetables.
Sherry Seethaler has a doctorate in science education and is a UCSD science writer and educator. Send your scientific questions to her at Quest, San Diego Union-Tribune, P.O. Box 120191, San Diego, CA 92112-0191. Or e-mail sseethaler@ucsd.edu. Please include your name, city of residence and phone number.
