Chapter 8

Question 1

Define free radicals and discuss how they can damage our cells.

Answer 1

Free radicals contain unpaired electrons They can destabilize other molecules and damage cells

Question 2

Describe how antioxidants protect our cells from the oxidative damage caused by free radicals.

Answer 2

Antioxidants stabilize free radicals 1. Antioxidants work independently by donating their electrons or hydrogen atoms to free radicals to stabilize them. 2. Antioxidant minerals act as cofactors, substances required to activate enzymes so that they can do their work.

Question 3

Which mineral discussed in class has the most significant antioxidant properties?

Answer 3

Selenium

Question 4

List three antioxidant vitamins. Which of these has the strongest antioxidant function?

Answer 4

A

C

E

Question 5

Identify diseases linked to free radical damage.

Answer 5

CancerHeart disease

Type 2 Diabetes

ArthritisCataracts

Kidney disease

Alzheimer’s disease

Parkinson’s disease

Question 6

Identify risk factors that increase likelihood of free radical formation.

Answer 6

Smoking,

Obisity,

Inactivity

UV radiation

Question 7

What is the RDA for Vitamin C?

Answer 7

Men - 90 mg

Women - 75 mg

Add 35 mg per day day for smokers

the Upper intake level 2000 mg per day

Question 8

Describe the relationship between antioxidant nutrients and our risk for cancer.

Answer 8

Within the body, antioxidants act as a defense against the damaging effects of free radicals. Free radicals are unstable, so they can damage cells, proteins and other genetic materials, such as DNA, thus leading to many health-related problems. Enzymes, which are proteins within the body, are known to contain antioxidants, as do nutrients such as vitamins A, C and E, selenium and beta carotene. During some studies, these nutrients have been given to patients to explore the relationship between antioxidants and cancer.

Question 9

What is beta carotene?

Answer 9

A precursur to Vitamin A

In the class of phytochemicals called carotenoids

A provitamin

Provitamins are inactive forms of vitamins that must be converted to active forms in the body.
Beta-carotene is the precursor of retinol, the active form of Vitamin A.

Functions of beta-carotene

Even before it is converted to vitamin A, beta-carotene is a weak antioxidant that protects cell membranes and LDLsOther carotenoids include alpha-carotene, lycopene, lutein, and zeaxanthin. These carotenoids also help protect the body from free radicals.

Carotenoids in general are known to

Support the immune systemProtect skin and eyes from damage by UV light

Carotene is the substance in carrots, pumpkins and sweet potatoes that colors them orange and is the most common form of carotene in plants.

Question 10

What is the RDA for vitamin C for men and women, smokers and non-smokers?

Answer 10

Recommended intake

RDA = 90 mg/day for men; 75 mg/day for women

Smokers need an extra 35 mg/day

Question 11

What is the UL for vitamin C?

Answer 11

2000 mg/day

Question 12

Where is Vitamin E found?

Answer 12

Vegetable oils, nuts, seeds, wheat germ, soybeans

Question 13

What is a pro-vitamin?

Answer 13

Provitamins are inactive forms of vitamins that must be converted to active forms in the body.
Beta-carotene is the precursor of retinol, the active form of Vitamin A.

Question 14

What food groups are important for cancer prevention?

Answer 14

Vegetables, fruits, fiber, phytochemicals

Soy based foods, and (contain progesterens)

Omega-3 Fatty Acids

Question 15

List vitamins and minerals that have antioxidant properties. Describe their functions and best food sources.

Answer 15

Vitamin E

Vitamin C

Beta-carotene

Vitamin A

Selenium

Question 16

Where is Vitamin A found?

Answer 16

Obtained from animal sources (liver, eggs) and, as the precursor beta-carotene, plant sources (dark green, orange, and deep yellow fruits and vegetables)

Question 17

Where is Vitamin C found?

Answer 17

Fresh fruits and vegetablesCooking at high temperature for long periods of time and excessive exposure to oxygen (such as when there is only a little orange juice left in a large carton) destroys vitamin C

Question 18

Where is selenium found?

Answer 18

High sources include organ meats, pork, seafood, nuts, whole wheat, brown rice

Question 19

List three antioxidant vitamins. Which of these has the strongest antioxidant function?

Answer 19

Vitamin A,E,C

The most active form of vitamin E in food and supplements is alpha-tocopherol

Question 20

Discuss how consuming nutrients with antioxidant properties can reduce our risk for cardiovascular disease.

Answer 20

We have learned that vitamin E, vitamin A, and other plant chemicals (phytochemicals) protect LDL. Why would protecting “bad” cholesterol be a good thing? LDL needs to be protected because once the LDL has suffered damage from free radicals it is even more likely to “stick” to artery walls and form heart attack and stroke promoting plaques.

Without adequate amounts of antioxidants, free radicals travel throughout the body, damaging cells. This cellular damage leads to the development of cardiovascular disease.

Question 21

What are the deficiency diseases for vitamins C?

Answer 21

Scurvy: is the most common vitamin C deficiency diseaseSymptoms of scurvy include bleeding gums, loose teeth, weakness

Question 22

What are the deficiency diseases for vitamins E?

Answer 22

Vitamin E deficiencies are uncommon. However, results from NHANES III suggest 27-41% of Americans may be low in vitamin E and, as a result, have increased risk for cardiovascular disease (from LDL not being protected).Vitamin E deficiency can result in erythrocyte hemolysis and anemia

Question 23

What if you don’t consume enough vitamin A?

Answer 23

Night blindness is the most common disease of vitamin A deficiency.

Question 24

What if you consume too much vitamin E?

Answer 24

Vitamin E toxicity is uncommon. However, one study found no benefit and hinted at potential harm from megadose supplements of vitamin E. This finding has not been confirmed by additional studies.Vitamin E can interfere with anticoagulant medications (aspirin and Coumadin) and cause uncontrollable bleedingLong term use in some people can cause hemorrhagic stroke

Question 25

What if you consume too much vitamin C?

Answer 25

Megadoses of vitamin C can cause nausea, diarrhea, nosebleeds, and abdominal crampsIf a person has hemochromatosis or preexisting kidney disease, excess Vitamin C can be harmful.

Question 26

What if you consume too much vitamin A?

Answer 26

Vitamin A is highly toxic, especially from supplements.Birth defects and permanent damage to the liver and eyes can result.

Question 27

What if you consume too much selenium?

Answer 27

Selenium toxicity (brittle hair, nails, skin rashes) can result from supplements.

Question 28

What is a megadose?

Answer 28

Although there is no clear-cut explanation of what exactly constitutes a vitamin megadose, according to Harvard University Medical School, it is generally a vitamin intake many times higher than the recommended amount. You can safely take some nutrients in high amounts, but do not exceed the IOM’s guidelines, as taking too much of some nutrients can cause toxicity and health problems.

Question 29

Describe low grade inflammation and how it relates to heart disease

Answer 29

Researchers are now recognizing low-grade inflammation in its central role in insulin resistance, diabetes, and cardiovascular disease. Understanding the underlying causes of inflammation will help guide prevention and treatment guidelines.