Oxygen in the body splits into single atoms with unpaired electrons, and electrons like to be in pairs. So, these atoms, called free radicals, scavenge the body to seek out other electrons to pair with. This causes damage to cells, proteins and DNA. Oftentimes, free radicals are associated with human diseases and may have a link to aging. Substances that generate free radicals can be found in the food, medicines, water and even, the air, but it is not possible to directly measure the amount of free radicals that are in the body.

Free radicals are the natural byproducts of chemical processes, such as metabolism. Dr. Lauri Wright, a registered dietitian and an assistant professor of nutrition at the University of South Florida, said, “Basically, I think of free radicals as waste products from various chemical reactions in the cell that when built up, harm the cells of the body.”

The Danger of Free Radicals

According to Rice University, once free radicals are formed, a chain reaction can occur. The first free radical pulls an electron from a molecule, which destabilizes the molecule and turns it into a free radical. That molecule then takes an electron from another molecule, destabilizing it and turning it into a free radical. This domino effect can eventually disrupt and damage the whole cell and may lead to the following dangers:

1. Broken cell membranes
2. Change the structure of a lipid, making it more likely to become trapped in an artery
3. The damaged molecules may mutate and grow tumors
4. Cascading damage may change DNA code
5. Damaged proteins, lipids and nucleic acids
6. Development of diseases such as: macular degeneration, cardiovascular disease, certain cancers, etc.

Antioxidants and Free Radicals

Antioxidants keep free radicals in check. Antioxidants are molecules in cells that prevent free radicals from taking electrons and causing damage. Antioxidants are able to give an electron to a free radical without becoming destabilized themselves, thus stopping the free radical chain reaction.

Well-known antioxidants include beta-carotene and other carotenoids, lutein, resveratrol, vitamin C, vitamin E, lycopene and other phytonutrients. Common sources are colorful fruits and vegetables such as tomatoes and spinach.

Oxidative stress is an imbalance between free radicals and antioxidants in your body. Symptoms of oxidative stress include: fatigue, headaches, noise sensitivity, memory loss and brain fog, muscle and joint pain, wrinkles and gray hair, vision trouble, and decreased immunity.

Exercise and Free Radicals

Regular physical exercise enhances antioxidant defenses. For example, aerobic exercise can induce oxidative stress due to fuel burnt in high-intensity cardio exercise causes chemical reactions that make free radicals form at a faster rate. Studies found that exercise alone was enough to build up antioxidant defenses against the initial exercise-induced oxidative stress.

Therefore, out of shape and infrequent exercisers who do a spontaneous bout of intense physical activity may invoke oxidative stress, while those who are consistently active should not worry.

source: livescience.com