Free radicals are unstable molecules that are formed when atoms or molecules gain or lose electrons. These highly reactive molecules can damage cells, proteins, and DNA in the body. Free radicals are produced naturally as a byproduct of metabolism, but they can also be generated by exposure to environmental factors such as pollution, radiation, and tobacco smoke. In small amounts, the body can neutralize free radicals using antioxidants, which are molecules that can donate electrons to stabilize the free radicals. However, if the balance between free radicals and antioxidants is disrupted, it can lead to oxidative stress, which can contribute to a range of diseases and conditions, including cancer, heart disease, and aging.

Free radicals are not present in foods themselves, but they can be generated in our bodies when we consume certain foods or when our bodies process food. For example, when we digest food, our bodies produce free radicals as a byproduct of metabolism. Additionally, some foods, such as processed foods and those high in fat and sugar, can promote the production of free radicals in the body. However, some foods are rich in antioxidants, which can help neutralize free radicals and prevent damage to our cells and tissues. Examples of antioxidant-rich foods include fruits, vegetables, nuts, and seeds.