Antioxidants are molecules that help prevent or slow down the damage caused by free radicals in the body. Free radicals are unstable molecules that can damage cells and contribute to aging and diseases such as cancer, heart disease, and Alzheimer`s disease. Antioxidants neutralize free radicals by donating an electron, which stabilizes them and reduces their ability to cause harm.

Regular intake of fresh fruits and vegetables is recommended in the diet since they are rich sources of antioxidants. By consuming antioxidants through diet or supplements, a person can reduce the damage caused by free radicals and promote longevity. Antioxidants also have other health benefits, such as reducing inflammation and improving the immune system.

The other options listed in the question are not accurate explanations of how antioxidants promote health and longevity. For example, antioxidants do not activate enzymes necessary for vitamin synthesis, but they can help prevent the breakdown of vitamins in the body. Similarly, they do not prevent the excessive oxidation of carbohydrates, fats, and proteins, but they can help reduce the damage caused by this process. Finally, while some studies suggest that antioxidants may activate certain genes and delay the aging process, the evidence is not yet conclusive.