Simply put, oxidative stress is an imbalance between free radicals and antioxidants. Both of these molecules are necessary for normal, healthy reactions in the body, but an excess of either can cause damage.
Free radicals are molecules which contain oxygen and have an uneven number of electrons. Because free radicals have an uneven number of electrons, they’re unstable and highly reactive with other molecules, which helps them cause large chain chemical reactions in the body. On the other hand, antioxidants are molecules that can give up an electron without becoming unstable, so they have the ability to stabilize free radicals.
When there are more free radicals than antioxidants can manage, oxidative stress occurs. Because free radicals are highly reactive, they cause damage to the body’s proteins, fatty tissue, and DNA in their quest for that stabilizing electron. Damage by free radicals can affect cellular function and cause apoptosis, also referred to as programmed cell death.
While our bodies’ cells regularly die and get replaced, prolonged damage by oxidative stress has been linked to a variety of diseases such as diabetes, cancer, inflammatory conditions, and neurodegenerative diseases like Parkinson’s and Alzheimers. Oxidative stress also contributes to the aging process and can affect skin’s collagen production and elasticity, causing wrinkles.
Causes of Oxidative Stress
But how does a surplus of free radicals occur? Everyone’s body naturally produces some free radicals, but everybody needs some free radicals in order to be healthy and help fight off infections. An excess of free radicals, and therefore a potential for lasting damage, can be a result of several environmental factors, like pollution, ozone, radiation, certain chemicals and pesticides, and cigarette smoke (including second-hand smoke).
Dietary factors can also play a role in excess free radicals. Diets high in fat, sugar, and alcohol can impact free radical production, and diets containing foods rich in antioxidants, like berries and dark, leafy greens, can introduce antioxidants to help manage free radicals.