Antioxidants are substances that protect cells from damage caused by free radicals . Free radicals are unstable molecules that are produced during normal biochemical reactions or are exposed to harmful factors such as pollution , smoking , alcohol , stress , sunlight , inflammation , infection , drugs or diet . Free radicals can damage DNA , proteins , fats , and other molecules in cells, which can lead to various diseases such as cancer, heart disease, diabetes, Alzheimer's disease, Parkinson's disease, aging, and more.
Antioxidants can neutralize free radicals, or promote their removal from the body, thus protecting cells from damage. Antioxidants are divided into two types : enzymatic and non-enzymatic. Enzymatic antioxidants are proteins that catalyze reactions that eliminate free radicals. Non-enzymatic antioxidants are molecules that react with free radicals and prevent them from damaging cells.
Antioxidants must be taken from food or from food supplements , because the body cannot produce them on its own or only in insufficient quantities. A lack of antioxidants can cause oxidative stress, which is a condition where there is an imbalance between the production and removal of free radicals . Oxidative stress can damage cells and increase the risk of disease.
An excess of antioxidants can also be harmful , as they can disrupt normal cell functions or interact with other substances. Therefore, it is important to follow the recommended daily doses of antioxidants and not to abuse dietary supplements.