AYA@USC and NutritionPart 3: The Role of Antioxidants

in Cancer

Presented by: Mei Leng Iao MS RD CNSCClinical Dietitian at USC Norris Cancer

Hospital

Agenda

• Free Radicals

• Antioxidants

• Diet and Lifestyle

• Conclusion

• Quiz

Cancer

• Risk Factors• Dietary Factors

• Lifestyle Factors (alcohol/tobacco)

• Genetics

• Viruses (HPV)

• Environmental Factors

• Aging

• Stress

Free Radicals

• What is a free radical?• A free radical is an unstable molecule

• Free radicals come from:• Our bodies – illness, medications

• Environment – pollution, tobacco smoke, X-rays, pesticides

• Free radicals – chain reactions

Free Radicals in Your DietHeterocyclic amines (HCAs) and polycyclic amines (PCAs)

•Cooking meat at very high temperatures produces heterocyclic amines. PhIP is the most abundant HCAs in burnt meat. High intake is associated with colorectum, breast, prostate, pancreas, lung, stomach, and esophagus.

•Charbroiling any red meat or chicken with the skin produces polycyclic hydrocarbons

•Similar compounds are produced with cigarette smoking

Hydrogenated Fats• Fats that are normally liquid at room temperature and by the process of adding

hydrogen to them solid. • margarines & shortenings

These products are added to many crackers, cookies and bakery products, because it extend their shelf life and keep the freshness. Important to read labels when buying foods.

• A study found that women that consumed a lot trans-fat found to be twice as likely to develop breast cancer.

High Fructose Corn Syrup• High fructose corn syrup is made from processed corn

starch, that is several times sweeter than sugar. Currently being used in place of sugar. Is present in many products such as: Soda pop, juices, sweets, breakfast cereals and desserts. It makes you feel les full and promote insulin resist/weight gain.

Nitrites & NitratesSubstances that are used as preservatives or added to meats to prevent spoilage by bacteria and extend shelf life

• Nitrites are normally occurring in some vegetables like kale or green cauliflowerWhen added to meats to prevent the growth of bacteria and meat from turning brown. However, when these processed meats exposed to high heat, the sodium nitrites and protein in meat will form nitroamines which are carcinogens.

• Get Fresh foods with minimal amounts of preservatives

Antioxidants

•What are Antioxidants • Free Radical Scavengers • Neutralize damage to the

body’s cells that can lead to cancer

• Naturally present in vegetables, fruits, whole grains, beans, nuts, herbs, and spices

Dietary Antioxidants

• Vitamin A

• Vitamin C

• Vitamin E

• Selenium

• Phytochemicals• Flavonoids• Carotenoids• Phenolic Compounds• Allium Compounds

Vitamin A

• Inactivates free radicals

• Food sources• Fortified Vitamin A products• Animal Products

• Beef liver, tuna, herring, sardines, eggs

• Fruits• Cantaloupe, mango

• Vegetables• Sweet potatoes, carrots, spinach, butternut squash, broccoli

• RDA• Men: 900 µg/day• Women: 700 µg/day

Vitamin C

•Stabilizes free radicals•Food Sources

• Fruits• Oranges, orange juice, papaya, cantaloupe, grapefruit, lemons,

strawberries, kiwi

• Vegetables• Spinach, broccoli, cauliflower, tomatoes, bell peppers, brussels

sprouts, potatoes

•RDA• Men: 90 mg/day• Women: 75mg/day

Vitamin E

• Terminates reactions involving free radicals

• Food Sources • Oils from plants

• Canola, olive, sunflower, safflower, cottonseed, soybean, corn, almond• Nuts

• Full fat food varieties• Salad dressing, mayonnaise

• Whole grains• Wheat, barley, rice, oats

• Legumes

• RDA• 15 mg/day

Selenium

•Protect cells against destruction

by free radicals

•Sources of Selenium• Plant food

• Soil concentration is directly related to selenium’s concentration in plant foods

• Animal Products• Organ meats, seafood, dairy products

• Nuts and Grains• Brazil nuts, enriched breads and pasta

Phytochemicals

• Biologically active, naturally occurring compounds in plant foods that have protective or disease preventive properties.

• Plant pigments

• Flavonoids• Carotenoids• Phenolic Compounds• Allium Compounds

Flavonoids

• Colors: red, purple, green, white

• Red grapes, blueberries, cherries, cranberries, red cabbage, raspberries, apples, pears, onions, soybeans, kale, broccoli, garlic, green tea, cocoa

Carotenoids

• Colors: yellow, orange, red

• Mangoes, cantaloupe, apricots, papayas, carrots, pumpkins, sweet potatoes, corn

Phenolic Compounds

• Colors: orange, white, green, red

• Berries, prunes, rinds of citrus fruits, cabbage, bok choy, collard greens, watercress, turnip greens, broccoli, cauliflower, kale

Allium Compounds

• Colors: white, green

• Garlic, onions, chives, leeks, scallions

Phytochemicals by their colors

Color Group Phytochemicals Fruits and Vegetables

Red Lycopene Tomatoes, Tomato Sauce, Vegetable Juice,

Tomato Soup, Watermelon, Red Grapefruit,

Guava, Dried Apricots

Green Flavonoids

Indoles

Broccoli, Brussels Sprouts, Bok Choy,

Cauliflower, Cabbage, Parsley, Green

Peppers, Spinach, Green Tea

Green/Yellow Lutein

Zeaxanthin

Corn, Avocado, Kale, Green Beans

Green Peppers, Kiwi, Collard Greens

Mustard Greens

Orange Carotenoids (Beta carotene) Carrots, Pumpkins, Butternut Squash,

Mangos, Apricots, Cantaloupe, Sweet

Potatoes

Orange/Yellow Carotenoids

Flavonoids

Oranges, Orange Juice, Tangerines, Yellow

Grapefruit, Peaches, Lemons, Limes,

Papaya, Pineapple, Nectarines

Red-Purple Anthocyanins

Resveratrol

Ellagic Acid

Flavonoids

Grapes and Grape Juice, Cherries, Red

Wine, Strawberries, Blueberries,

Blackberries, Raspberries, Cranberries,

Plums, Prunes, Raisins, Beets

White/Green Allyl Sulfides

Indoles

Garlic, Onion, Chives, Cruciferous

Vegetables

Other Antioxidant Sources

• Herbs and Spices • Ground cloves, cinnamon, oregano, rosemary, sage, thyme, paprika,

curcumin

• Dark chocolate• 50-85% cocoa solids

Food with high amount of antioxidants

• Green tea• Epigallocatechin gallate (EGCG), has more powerful antioxidant effects than

vit C and E. Found to deactivate carcinogens, inhibits tumor growth and inducing cancer cell death in animal study. May reduce risk of breast, ovary, endometrium and prostate cancer.

• Omega 3 fatty acids• Protect again cancer by decrease the inflammation, cell proliferation and

angiogenesis.

• Flaxseed• ALA and lignans, reduce risk of postmenopausal breast cancer, and in animal

study, flaxseed inhibits the growth and metastasis of prostate cancer.

• Curcumin • Turmeric, has strong antioxidant and anti-inflammatory properties. Inhibit

tumor growth, and metastasis. Appeared to be promising in preventing colorectal and pancreatic cancers

Top Antioxidant Foods[ORAC* units per 100 grams**]

Fruits Vegetables

Goji Berry 25,000 Garlic 1939

Prunes 5770 Kale 1770

Raisins 2830 Spinach 1260

Blueberries 2400 Brussels sprouts 980

Blackberries 2036 Alfalfa sprouts 930

Strawberries 1540 Broccoli florets 890

Raspberries 1220 Beets 840

Plums 949 Red bell peppers 710

Oranges 750 Onions 450

Red grapes 739 Corn 400

Apples218 Potato 300

* Oxygen Radical Absorbance CapacityDeveloped by the National Institute of Aging USDA recommends 3000-5000 ORAC units/d

**About 3.5 ounces

Diet and Lifestyle

•Divide your plate• ½ plate vegetables

• ¼ plate protein

• ¼ plate carbohydrates

•↓ Fat and ↑ Fiber

Limiting Fat Intake

• < 30% calories (~67g), <10% calories (~7g) from saturated fat, per day (based on 2000 kcal)

• Choose fats and oils with 2 grams or less saturated fat per tablespoon

• Boil, broil, grill, bake, roast, poach, steam, sauté, or stir-fry.

• Non-stick spray oil

• Trim fat from meat and poultry. Drain fat after browning.

• Purchase low fat or non-fat food varieties

Serving Sizes*

Chopped Vegetables ½ cup

Raw Leafy Vegetables 1 cup

Fresh Fruit 1 medium piece

½ cup chopped

Dried Fruit ¼ cup

Pasta, Rice, Cooked Cereal ½ cup

Ready-to-Eat Cereal 1 oz. (varies ½ cup – 1 ¼ cup)

Meat, Poulty, Seafood 3 oz.

Dried Beans ½ cup cooked

Nuts 1/3 cup

Cheese 1 ½ oz (2 oz if processed)

Food Serving Size

*According to the American Cancer Research Institute

Visual Serving Sizes

• 1 fruit serving= ½ cup canned or 1 medium fruit • About the size of a tennis ball

• 1 meat, poultry or fish serving= 3 oz• About the size of a deck of cards

• 1 grain= 1 slice bread, pre-sliced, 1/2 cup pasta• About the size of a CD case

• 1 dairy serving=8 ounces• The size of a container of individual yogurt

• 1 vegetable serving = 1/2 cup cooked or canned vegetables • About ½ a baseball)

• 1 fat serving= 1 teaspoon • About the size of your thumb tip

1/2 cup 1 cup = =

Lifestyle

•Moderate Exercise• 30 minutes of activity, five or more times per week (150

minutes of moderate exercise or 75 min vigorous exercise (or whatever your doctor recommends)

•Reduce Stress• Take 15 to 20 minutes a day to sit quietly, breathe deeply

and think of a peaceful picture• Try to learn to accept things you can’t change

• Limit alcohol, don’t overeat and don’t smoke

Safety

• Vegetables and fruits are rich sources of antioxidants and concerns have not been raised about the safety of antioxidants in food.

• However, high dose supplements may link to health risk in some case• High dose beta-carotene->increase risk of lung cancer in smoker

• High dose vitamin E increase risk of prostate cancer and a type of stroke

• Antioxidant supplements may interact with some medicine • Vitamin E supplements may increase risk of bleeding with people that are

taking anticoagulant drug

• Some antioxidants are found to be harmful with chemo regimen, but some found beneficial, results are not conclusive

• St. John wort may reduce concentrations of some drug including imatinib and irinotecan

• Omega 3 fats may reduce toxicity of Irinotecan and Paclitaxel, enhance clinical benefit of Doxorubicin, Cisplatin and Vincristine

Conclusion

• Do not use antioxidant supplements to replace a healthy diet or conventional medical care .

• If you are considering taking a dietary supplements, please consult your healthcare provider first to get reliable information. Remember some of the supplements can interact with your medication.

• Tell all your healthcare providers about any supplements that you are taking, and this will help ensure coordination and safe care.

• Until more studies are done, it is best to get your antioxidants from a diet rich in fruits and vegetables rather than from supplements.

Quiz!!!!!

• True of False• 1. Free radicals cause damage?

• 2. Vitamins A, B, C, D, and E are all antioxidants?

• 3. Phytochemicals are found in plants and animals?

• 4. A serving of raw vegetables is 1 cup?

• 5. The best antioxidants sources are from supplements?

References

• Gropper, S., Smith, J., Groff, J. Advanced Nutrition and Human Metabolism 4th edition. Thompson; 2004.

• Mahan LK, Escott-Stump S. Krause’s Food, Nutrition, and Diet Therapy, 11th edition. Philadelphia, PA: Saunders; 2004

• American Institute for Cancer Research at http://www.aicr.org

• United States Department of Agriculture at http://www.usda.gov

• United States Food and Drug Administration at http://www.fda.gov

• Office of Dietary Supplements at http://www.ods.od.nih.gov

• https://www.heart.org/en/healthy-living/healthy-eating/add-color/fruits-and-vegetables-serving-sizes

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