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Phytochemicals and Genetically Modified Food. Unit 21. Phytochemicals. People who eat lots of fruits, vegetables, whole grains and other plant foods are less likely to develop many health problems Plants contain thousands of potentially beneficial substances called phytochemicals. Key Terms.
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Phytochemicals • People who eat lots of fruits, vegetables, whole grains and other plant foods are less likely to develop many health problems • Plants contain thousands of potentially beneficial substances called phytochemicals
Key Terms • Phytochemicals • Chemical substances in plants which likely perform important functions in the body • Zoochemicals • Chemical substances in animal foods which likely perform important functions in the body
Characteristics of Phytochemicals • Functions in plants: • Provide color and flavor • Protect from insects, microbes, oxidation • Used in energy processes, hormones • Not all phytochemicals are healthful • Naturally occurring toxins
Phytochemicals and Health • Diets rich in phytochemicals protect against many diseases • Heart disease, certain cancers, infectious diseases, osteoporosis, type 2 diabetes, stroke, hypertension, cataracts, age-related macular degeneration, and other disorders
Age-Related Macular Degeneration • Age-related macular degeneration • Eye damage caused by oxidation of the macula (central portion of eye responsible for detail) • Leading cause of blindness in adults over 65 • Prevented by carotenoids (antioxidants)
Cataracts • Cataracts • Complete or partial clouding of the lens of the eye
Phytochemicals Work in Groups • Most (if not all) phytochemicals work together when consumed at the same time • Pills containing individual phytochemicals don’t have the same effect
Beta-Carotene Studies • Smokers with high beta carotene levels from fruits and vegetables had low cancer rates • Smokers who took beta carotene supplements had higher cancer rates • Conclusion: A combination of chemicals in plant foods reduced cancer
It would take 100 pills to get the same amount of just one phytochemical (sulforaphane) in one serving of cruciferous vegetables such as broccoli Vegetable Extracts and Essences
Key Terms • Cruciferous vegetables • Sulfur-containing vegetables whose outer leaves form a cross (crucifix) • Includes broccoli, cabbage, cauliflower, brussels sprouts, mustard, collard greens, kale, bok choy, kohlrabi, turnips, broccoflower, and watercress
How Do Phytochemicals Work? • Phytochemicals can: • Act as hormone-inhibiting substances to prevent initiation of cancer • Act as antioxidants that prevent and repair damage due to oxidation • Neutralize enzymes that promote cancer • Modify utilization of cholesterol • Decrease formation of blood clots
Bright-colored pigments are strong antioxidants Zeaxanthin Anthocyanin Lycopene Top Antioxidants
Solanine In green potatoes Oxalic acid In dark green, leafy vegetables Cyanide In cassava Naturally-Occurring Food Toxins
Naturally-Occurring Food Toxins • Ackee fruit • Part edible, part deadly poison
Caffeine is a habit-forming phytochemical Withdrawal can cause headaches Caffeine
Genetically Modified (GM) Foods • Genetic engineering • Process of biotechnology used to modify the composition of a food by altering its genetic makeup – includes transfer of genes from one species to another • Food products produced are sometimes called GM or GMOs (genetically modified organisms)
Genetic Modification of Animals • Biotechnology has also genetically engineered animals used for food • Atlantic salmon, pigs, cattle, chickens • Animal products from cloned animals make up a small fraction of meat sales
Are GM Foods Safe? • Over 60% of processed foods contain GM ingredients • 80% of soybeans, 30% of corn are GM • Tomatoes, squash, cantaloupe, potatoes • Organic produce is not GM
