Intro to Nutrition Chapter 8 Antioxidants

what is oxidation?

chemical reaction when an atom loses an electron

what is the exchange reaction?

an even exchange of electrons that keeps atoms stable

what is a free radical?

atoms that lose an electron and do not immediately gain another become unstable

how do free radicals cause problems?

they steal electrons from stable atoms, causing a chain reaction of free radicals

what is an antioxidant?

vitamins that stabilize free radicals

how do antioxidants work?

they donate their electrons or hydrogen atoms and remain stable

what is superoxide dismutase?

an antioxidant enzyme system that converts free radicals into less damaging substances like hydrogen peroxide

what is catalase and glutathione peroxidase?

antioxidant enzyme systems that remove hydrogen peroxide by converting it to water and oxygen

how might antioxidants relate to cancer risk?

antioxidant supplements can increase your risk for cancer, while antioxidant nutrients prevent it

what is the function of vitamin E?

antioxidant and protects fat

what is the RDA for vitamin E?

15 mg/day

what are good food sources of vitamin E?

sunflower seeds, almonds, plant oils

what can cause vitamin E deficiency?

disease and malabsorption

what are the symptoms of toxicity from vitamin E supplements?

nausea, intestinal distress, diarrhea. serious conditions risk prostate cancer, premature mortality, hemorrhage stroke

what is the function of vitamin C?

antioxidant

what is the RDA for vitamin C?

75 mg/day for women, 90 mg/day for men, smokers need RDA+35

what are good food sources of vitamin C?

fresh fruits and veggies

what are the symptoms of toxicity from vitamin C supplements?

nausea, diarrhea, nosebleeds, abdominal cramps

what is the function of vitamin A?

improves vision and works in cell differentiation

what is the RDA for vitamin A?

700 mg/day for women, 900 mg/day for men

what are good food sources of vitamin A?

ONLY in animal products like meat, eggs, dairy

why is vitamin A deficiency serious?

it can cause irreversible blindness and follicular hyperkeratosis

what are the symptoms of toxicity from vitamin A supplements?

birth defects, illness, death, permanent damage to organs

what is the function of selenium?

needed for the production of thyroid hormones and good immunity

what is the RDA for selenium?

55 mg/day

what are good food sources of selenium?

fish and dairy products

what can be caused by selenium deficiency?

Kashan disease and deforming arthritis

what are the symptoms of toxicity from selenium supplements?

brittle hair and nails, skin rash, nausea, vomiting, weakness

what is the function of prooxidants copper, iron, zinc, and manganese?

metabolism for healthy tissue and blood