Final answer:
Dietary antioxidants are found in fruits and vegetables and protect the body against free radicals. They work by being oxidized to stop the chain reactions caused by free radicals, with vitamins C, E, beta-carotene, and selenium being key antioxidants.
Step-by-step explanation:
Dietary antioxidants are compounds typically found in fruits and vegetables. They play a crucial role in protecting the body against the harmful effects of free radicals, which are highly reactive molecules with unpaired electrons. Free radicals can be naturally produced during metabolic processes or can come from environmental factors like radiation and pollution.
Antioxidants work by being oxidized themselves, thereby halting the destructive reaction cascades initiated by free radicals. Key antioxidants include vitamins C and E, as well as the provitamin β-carotene, which can be converted into vitamin A in the body. Another important mineral with antioxidant properties is selenium.
Vitamin E (tocopherol) acts as an antioxidant by scavenging harmful by-products of metabolism, such as free radicals. It can also prevent fats in foods from becoming rancid due to oxidation. Vitamin C is also known for its antioxidant capabilities, reducing potentially damaging oxidation of living cells and transforming into dehydroascorbic acid in the process.